Transportation and Development Innovative Best Practices 2008

Transportation infrastructure is critical to economic and land development in industrialized and industrializing nations. However, dispute over the responsibility for funding and implementation of off-site transportation infrastructure improvements frequently occurs. While public agencies often desire development, they bear the responsibility of ensuring that it does not degrade the mobility and safety of the nearby surface transportation network for the traveling public. Private developers seek adequate access to their property, but at times feel there is unfair burden on the private sector to fund and implement off-site improvements. The purpose of this paper is to examine the process for the implementation of off-site transportation improvements associated with land development in the Commonwealth of Pennsylvania, United States, and compare it to best practices in the United States. Currently in Pennsylvania there are two regulatory means by which local and state agencies may require private developers to fund off-site improvements. At the state level, the Pennsylvania Department of Transportation (PennDOT), through their permitting process, may require developers to fund and construct improvements as determined from the preparation of a traffic impact study (TIS). At the local level, municipalities may adopt a traffic impact fee ordinance. This ordinance allows municipalities to assess developers a fee on a per vehicle trip basis to construct off-site improvements. However, few municipalities have enacted traffic impact fee ordinances due to its cumbersome, costly process. In addition, the PennDOT TIS / permitting process is not an exact science, in terms of determining an equitable distribution of improvement implementation responsibility. This paper describes the current process for implementing off-site transportation improvements associated with land development, examines their pros and cons, and compares it with best practices in the United States.

Globalization is shaping a new socio-economic order with profound, and still unfolding, implications for transportation development. A prerequisite for national competitiveness in the global market place is efficacious transportation when its recent technological advances have created an unprecedented rise in mobility and accessibility. Developments of efficient and effective transportation infrastructure and services are among the principal driving forces for the globalization process. Using international databanks, this paper describes an attempt to shed some light on national trends of globalization and transportation, and their relationships. Deploying a comparative macroscopic approach and using relevant time-series statistics, the study provided some quantitative clues of the possible interrelationships between globalization and transportation.

This paper shows how Asian cities are leading the way to sustainable mobility based on a set of selected indicators. The reasoning behind the selection of the indicators is discussed. They focus on measuring the sustainability of personal mobility (versus freight mobility) for land-based transportation. Using the selected indicator set a comparative analysis is presented showing how Asian cities compare with major metropolitan areas in the United States, Canada, Australia, Europe and other countries. The paper will discuss the areas of sustainable mobility where Asian cities are performing well and which categories they need to improve on. From the analysis, the paper will demonstrate why Asian cities are currently leading the way to sustainable mobility. The challenge for Asian cities is whether they can maintain their leadership in this area and how they can improve on other issues, in particular air quality and traffic congestion. The paper provides a summary of development best practices based on the experience of developed countries, in order for Asian cities to continue to take the lead in providing sustainable mobility.

In view of the greater attention being paid today to such problems as pollution, the traffic congestion that contributes mightily to it, and the ever-increasing cost of gasoline, a recent planning process in Honolulu offers a timely look at how the decisions regarding a new mass-transit system were made and why. Honolulu's linear city layout, mountainous topography, and high density land-use make it ideal for a grade-separated transit system. Multiple efforts to plan a high-capacity mass transit system for Honolulu have occurred over the past several decades, and have been aborted at least three times since the 1970's. Through these floundered processes, it was learned that building a fixed guideway transit system takes more than sophisticated planning and engineering, it takes political will, public support, and a dedicated, predictable source of funding as well. This paper explains the most recent planning process for a new mass-transit system in Honolulu. It summarizes the debating points persistent since the beginning of the previous planning efforts. It was through these healthy debates that a broad consensus was reached on exactly what alternative best met locally defined goals and objectives for the specified corridor.

To support balanced and sustained economic returns from transportation investment, the convergence of development strategies on a regional scale is crucial. Recognizing that regional economies are shaped by unique geostrategic conditions, effective transportation development must be planned in the context of regional urbanization dynamics. This paper examines the development patterns of the Pearl River Delta region in Guangdong province, serving as a case study for exploring broad strategies that best promote balanced regional growth through transportation investment and development. Based on a methodical assessment of strengths and weaknesses in the region, the rural periphery was identified as an underutilized asset crucial to supporting balanced regional growth. Recommended best practice strategies emphasize the role of policy-making and transport infrastructure as allocative mechanisms in a regional economy.

The U.S. government allowed the Interstate System to become compromised when it failed for decades to properly adjust for inflation the gasoline excise tax used to fund the system and increasingly diverted federal fuel-tax revenues to purposes other than roads. In addition, during the same time period, increases in the cost of road construction significantly outpaced inflation. Privatization, on the other hand, will bring about a series of benefits: it will provide new, much-needed, private capital; facilities will be built more quickly and more efficiently and operated more cost-effectively; execution and pricing risk will be transferred from the public sector to private investors, which can bear more risk and thus may develop more innovative solutions; and new sources of tax revenue will be created.

Accurate project cost and schedule estimates are a critical component of transportation project decisions. While many owner/agency organizations have had successful estimating experiences, worldwide data suggest that engineers and planners have systematically under-estimated the ultimate costs and schedules for large transportation infrastructure projects; one study suggests up to 90% of estimates for transportation infrastructure projects have been low and, on average, cost estimates for transportation projects have been 20% short of final costs. This paper briefly summarizes an innovative and flexible probabilistic, risk-based approach to addressing these problems in a practical and cost-effective way.

The Wasatch Front Regional Council has developed and tested the UrbanSim land use modeling system for the Greater Salt Lake Region of Utah. The UrbanSim model is integrated with the regional travel models, and this integrated model system is an advanced analytical framework used to help develop long-range land use forecasts and to evaluate land-use and transportation scenarios in the Regional Transportation Planning process. This paper will provide an overview of the WFRC modeling process, and describe the recent application of the modeling system during the Wasatch Choices 2040 Visioning effort.

Urban cities around the world are busy finding ways to manage traffic congestion that increasingly reduces the quality of life of the citizens and the productivity of the city. Many governments of developed countries had already learned that building your way out of congestion is totally cost ineffective and counterproductive, and is certainly not a recommended long-term strategy for congestion management. Instead, transportation professionals are calling the attention of the policymakers to focus on integration of land use and transportation as an effective mean to manage congestion. While coordinated land use planning can certainly help to enhance the movements of people and goods for the two primary modes of transportation, automobiles and public transport, the presentation will concentrate on the public transport sector instead of the highway sector. It will introduce the concept of Transit Oriented Development including background and principles, and the discussion will touch on of the following technical elements: 1 Factors that favoring and hindering development around transit, 2 The elements of Transit-Oriented Planning, 3 Accommodating the terminal/station function, 4 Principles for successful development around stations/terminals.

Urban transportation planning in Beijing has not been well integrated with land use strategy. Limited land supply cannot meet the demands placed on the transportation system, resulting in newly constructed roadways becoming congestion after a short period of time. Using the method of data envelopment analysis (DEA) and the idea of membership degree of fuzzy mathematics, the evaluation model of a composite system was proposed. State and dynamic degrees of coordination displayed the different temporal concepts. Indexes were then selected and the degree of coordination for Beijing was calculated. From this analysis the conclusion can be drawn that development and transportation in Beijing have not been coordinated in the past several years. This conclusion is also supported by objective data. The example verifies the viability of the model.

The collection of feedback and adjustments to operations and services in response to motorists' needs and perceptions is presented. Surveys for commercial customers, manual toll payers and electronic toll payers are described, along with main results. New products are toll subscription packages that respond to varied needs and frequencies of travel. Services range from the location where electronic transponders are sold to response times and types of aid offered for incidents on the freeway.

This paper reports the results of a stated-preference survey of mode choice under different parking fees in downtown Beijing during the morning peak period. The respondents' preferences are estimated by means of a Multinomial Logit Model. The main findings indicate that drivers are sensitive to parking fees, and that, assuming low parking fees outside the central city, the major effect of a high parking fee downtown is the shifting to parking outside the downtown area and riding transit to internal destinations (P&R.) A high degree of travel demand elasticity is found and a specific parking fee policy for Beijing is recommended.

Making comprehensive urban transportation policies and decisions under the dynamic and complex environment of the Chinese institutional structure for planning is, to put it lightly, not a simple task. In addition to the traditional conflicting interests inherent in any transport project, there is an additional layer of challenge posed by Chinese planning approvals and incentive structures. Given this environment, the need for an intuitive, simple system to quickly evaluate project alternatives and to readily articulate the performance of an existing system is acute. Project sponsors need to be able to readily answer questions such as: 1 Which is a better alternative to serve the transportation goals and needs of the project? (evaluate alternatives within project), 2 What is a better choice between modal options to serve the city or communities? (new highway via public transport line), 3 What are the best transportation options for the city in the near term and in the long term? (master planning), 4 What are the transportation priorities under various levels of financial constraints? (capital programming), 5 How do transportation policies impact the quality of life of the people who are living in the study area? (environmental and community impact assessment). Establishment of standardized transportation "performance measures" could be an effective method to overcome these challenges. This paper will share the concept of and experiences in developing performance measures through examples.

Investments on the construction of transportation infrastructure have a great effect on the national economy of any country. Infrastructure includes the transport networks such as railways, highways, and waterways. This article examines the transportation infrastructure construction contribution on both of the national product growth and the personnel employment growth in China for the year of 2002. This examination was done based on input-output method and industry correlation theory which applies the output, investment, employment multiplication in order to quantify the investments effects on the transportation infrastructure construction for the Chinese economy. The obtained results showed that the scale of transportation infrastructure construction is small at present in comparison with many others countries which will lead to lower the growth rates and productivity of the Chinese economy in the near future. This paper concludes that the Chinese government should strength the administration of macro-economy in order to exert the function of the transportation infrastructure for the economy development.

The Yangtze River, at 6300 km long, is the longest river in China and a key transportation corridor in China's booming economy. The implementation of the National Freeway Planning and National Long-term Railway Planning programs will create a comprehensive transportation corridor along the river, consisting of railway, roads, waterway, aviation and pipeline infrastructure. The development of this transportation infrastructure will be the impetus for continued development within the Yangtze River economic region, further fuelling growth in the Chinese economy. This paper applies the concept of the "transportation-economic belt"; i.e. — that construction of a comprehensive transportation corridor creates the impetus for formation of a "belt", or linear region, of high-growth economic activity around the corridor. Using the comparison of one of the world's first comprehensive transportation corridors — the Rhine River — the inherent relationship between industrial development and transportation is examined. Using this historical perspective and the transportation-economic belt concept, the paper suggests mitigation measures that could be adopted to manage growth, and to address the possible negative effects of rapid growth and industrialization.

Traffic jams, air pollution, lack of exercise — these are problems that a large majority of us face every day. Cycling is one of the best solutions to all of them: it is an active contribution to creating an urban environment with less traffic and better air quality, it helps people to improve their well-being and contributes to a better quality of life in urban areas. The Municipality of Bolzano Bozen, located in South Tyrol (Italy), has been promoting bike mobility for several years. As an overall result, the modal split of bike mobility in this town rose from 17% to 25% in less than five years. This paper gives an overview of the results achieved through several projects and activities implemented in collaboration with the Ökoinstitut Südtirol/Alto Adige.

Despite unprecedented motorization in China, most Chinese still rely on non-motorized modes. As a result of rising incomes and a long legacy of bicycle use, electric powered two-wheelers have risen in popularity over the past five years and the country has seen tremendous growth of this mode. Touted as environmentally friendly vehicles, they are capable of traveling about 40–50 kilometers on a single charge and emit zero tailpipe emissions. However, many cities are banning electric two-wheelers from city streets, citing safety and environmental problems. This research quantifies both the negative externalities (environmental and safety impacts) and positive mobility benefits of electric two-wheelers in China. Electric bikes perform well on most metrics, although their use results in much higher environmental lead emissions from battery production and disposal than any alternative. They do however provide unmatched, cost effective mobility and accessibility advantages compared to most alternative modes.

The large population and urban mixed traffic flow have caused many urban traffic problems in China. This paper considers the basic factors that influence the choice behaviors of individual travelers, and presents a system optimization model for urban mixed traffic networks using bi-level programming. The model uses the variational inequality method and increases optimization for an urban mixed traffic system and provides a powerful tool to improve city traffic situations. A case study to illustrate the applications of the model and its algorithm is also included in the paper.

Although a significant number of trips are made by foot in developing cities, pedestrian infrastructure, amenities, and services are often neglected in municipal planning and budgets. This paper presents the processes and results in the development of a Walkability Index, which would rank cities within a country and across the world based on the safety, security, and convenience of their pedestrian environments. The Index is a tool that could be easily and economically implemented throughout Chinese cities to raise awareness of walkability as a critical issue, and more importantly, provide cities with the data and information they need to develop informed investment plans and policy decisions. This paper provides a summary overview of how the Index is constructed and implemented.

This paper presents the application of simulation techniques to the design of the New Curaçao Airport Terminal. The purpose of the simulation is to confirm that the design will meet or exceed IATA Level of Service C (LOS C) planning standards during periods of peak activity of the design day. The simulation model is a dynamic, object-oriented passenger movement analysis tool. The model is driven by a realistic flight schedule developed for a 24-hour design day, thereby providing passenger volumes and flows that reflect the arrival and departure of aircraft and passengers over the course of an entire day.

Congestion pricing strategy as a traffic demand management measure is widely accepted by the public. However, there is little focus on the research of optimal toll-areas. This paper puts forward the Second-best multi-class based bi-level planning model of road network congestion pricing in elastic demand, where the upper level model attempts to maximize the network social welfare by trying different tolls on some roads and the lower level model describes the route choice behavior of network users. A Multi-class user equilibrium Frank-Wolfe algorithm is used for the lower level model and a differential quotient algorithm of bi-level planning model is employed to find the optimal solution after function evaluations. Finally, on basis of the above model and algorithm, the optimal toll area is computed its toll level is simultaneously designed.

Scheduling of operational activities is a key step in port management. Port operation scheduling in China is normally based on empirical procedures that result in long ship berthing time, uneven distribution of duty cycle of machinery, and serious yard-block congestion. In view of this, this paper presents a simulation model for scheduling container terminals. The model provides information on equipment and port utilization as well as operational processes, thus providing managers with a valuable decision support tool for port operation scheduling.

The high economic cost and social impact associated with freeway incidents has prompted Traffic Management Agencies world-wide to develop incident management system (IMS) aiming to alleviate incident consequences. In order to reduce the response time and clear the incidents quickly and safely, an efficient and effective deployment of incident response resources, especially the service stations, is critical to IMS. The objective of this paper is to develop a tool to search for optimal locations of service stations along the freeway, to minimize the response time from the service stations to the incident sites. A dynamic programming approach is presented in this paper, followed by a case study to demonstrate the application of this optimization model in accordance with the status quo of China. With 20% reduction in total travel time, the model shows good potential in improving the incident response time.

In this paper, a method based on BP neural network is proposed to predict the hourly average concentrations of NO₂ on roadside near city arteries. The main factors that affect the hourly concentrations of NO₂ include O₃ concentrations, NO concentrations, traffic volumes and meteorological factors which contain atmospheric temperature, atmospheric pressure, wind speed, wind direction, relative humidity, rainfall and solar radiation. The hourly average data of these affecting factors were selected as the input neurons of the network. And the network was trained and validated with the data form an automatic monitoring experiment on roadside. As a comparison, a multiple linear regression model was established. When predicting NO₂ concentrations with the neural network approach, the mean absolute value of relative error of training and validation result was 7.19%, and the correlation coefficient between the predicted and monitored concentrations was 0.99, which was much better than the prediction with a multiple linear regression model.

Urban short-term traffic flow data is highly nonlinear and with time-varying characteristics, especially changing abruptly before and after a period of congestion. In this paper, a Markov switching (MS) model is proposed to model the short-term traffic flow forecasting. The model is suitable to describe a nonlinear time series of urban traffic flow. The proposed model classifies traffic flow conditions into two states corresponding to two regimes of the MS model respectively. The traffic flow model changes under each state, switching at a certain probability controlled by a first-order Markov chain. Comparisons with real data for traffic flow validate the method with accurate short-term forecasts.

While cellular probe traffic data shows its great potential in applications of Intelligent Transportation System (ITS), especially, the Traveler Information System (TIS), the data quality becomes a more and more important issue for real world application. The purpose of the paper is to discuss the issues in probe data evaluation and their potential solution approaches. The selections of data source, sampling strategies and data analysis techniques can be complicated problems. A case study is presented. It is observed in the study that cellular probe traffic data provide ideal spatial and temporal coverage and the precision of the cellular probe traffic travel times on freeways qualifies immediate ITS application. It indicates that it is necessary to further improve the algorithm on arterials and to coordinate signal setting within the algorithm. With future improvement of cellular probe technology, ITS applications will be further benefited.

This study presents a practical approach to transit system planning using microscopic simulation with emphasis on operational issues. The microscopic simulation model can generate detailed estimates of traffic conditions considering time-varying demand and individual driver's behavior. Therefore, it can evaluate drivers' interactions with complex traffic environment and analyze the impact of major roadwork improvement and/or advanced transportation management strategies on the transit and traffic operations. A microsimulation-based transit planning practice is presented as case study. Exhaustive analyses combining various alignments and three transit technologies including BRT, LGR, and AGT are conducted to evaluate the performance of each alternative. The case study demonstrates the feasibility, applicability and benefits of the proposed approach.

This paper first analyzes link and route travel time distributions in a degradable road network by assuming a uniform distribution on the capacity of each link. It is postulated that travelers, by acquiring route travel time variability from past experiences, make route decisions based on a travel time budget, which is the summation of the mean route travel time and the safety margin of the travel time. This paper then formulates a novel travel time budget-based stochastic user equilibrium traffic assignment model with multiple user classes and elastic demand as a variational inequality problem. Finally, a numerical example of a small road network is presented to illustrate the properties of the proposed model.

In order to investigate the suitability and potential benefits of applying land-use forecasting models in China, this paper presents an immune genetic algorithm for the calibration of Lowry model based on a maximum likelihood approach. The calibration procedure comprises three stages. In the first stage, an immune genetic algorithm is employed to calibrate the population and employment potentials, together with a coefficient associated with the travel impedance function in the study area. The second stage investigates the relationship between the calibrated potentials and various land-use variables, using a multivariate stepwise regression analysis. The third stage is model validation. A case study of Hu Zhou city, in Zhe Jiang province of China, was employed to demonstrate the performance of the proposed methodology. The results indicate that the calibrated Lowry model is acceptable for forecasting the future population and employment distribution in China.

The fuzzy logic controller (FLC) presented in this paper simulates the control logic of experienced human traffic controllers such as police officers who supersede signal controls at over-saturated intersections during special events. Given real-time traffic information, the FLC controller decides on whether to extend or terminate the current green phase based on a set of fuzzy rules. A microscopic simulator, the Intersection Control Simulator (ICS), was developed to facilitate the evaluation of the proposed FLC strategy. The FLC strategy was compared with pretimed and actuated control strategies using a typical intersection with varying traffic volume levels. Based on delay, speed, % stops, time in queue and throughput-to-demand ratio statistics, the FLC strategy produced significant improvements over pretimed and actuated control strategies under heavy traffic volumes. This indicates that FLC has the potential to improve operations at over-saturated intersections.

Relieving traffic congestion on roadway has always been one of the prior concerns of traffic engineering. Thoroughly understanding the factors which cause traffic jams plays the fundamental role in planning, design, construction and management of roadway facilities. This paper focuses on experimental observations and theoretical analysis of urban freeway congestion due to complex features of traffic flow, shock wave and state transition. Real time detected data were collected to calculate shock wave speed and establish vehicle trajectory models. A typical urban freeway segment in the center of Shanghai City is used in this analysis. As a result, conclusions have been drawn and the theory of shock wave speed could be used to help establishing traffic control strategies and to control queue length.

In order to meet the need of traffic route guidance and traffic monitoring system in urban areas, this paper introduces a method to estimate and predict traffic condition and travel time between arbitrary locations by utilizing the Extended Kalman Filtering (EKF) framework. The basic concept is to first predict future traffic conditions using macroscopic dynamic models that are integrated with EKF based on the fixed traffic detectors in urban areas, and then predict actual travel time using "fictitious car" method. Finally, a case study in Shanghai is presented. The results demonstrate acceptable applicability and precision of the method. This study may lead to better traffic control and traffic route guidance, and improve the accuracy of broadcasted traffic conditions.

Intersection traffic safety management includes basic intersection information, safety evaluation, safety problem diagnosis, and countermeasure recommendations. In this paper, a new approach to improve the efficiency of safety evaluation is proposed: GIS-based model of safety level-of-service. Field ratings were used to initially screen intersection information. After entering intersection information into a computer model, the system automatically evaluates the safety of intersection, identifies existing safety problems and recommends prioritized countermeasures based on a benefit-cost ratio model. Initial results show the system improves the efficiency of evaluating and selecting intersection safety improvements.

Urban transport problems resulting from high levels of mobility and car usage are major challenges facing most urban areas worldwide. While past decades saw various transport policies and measures to restrict and manage car usage in the cities, it has been increasingly recognized that urban form, development patterns, and density levels affect travel behavior and car usage, and that therefore urban planning can be a major tool in solving transport and traffic problems. Sustainable development debates support this line of thought, emphasizing the most appropriate urban form for creating sustainable urban transport systems. Certain planning approaches, such as intensification of urban development and corridor development that support public transport usage, together with higher density and diversity in development, are promoted as sustainable alternatives to the prevailing lower-density urban sprawl. This paper assesses the effectiveness of such planning approaches, focusing on the planning experiences of Ankara, the capital of Turkey.

Statistical analyses have shown that the death rate per 100,000 persons in traffic and transportation related deaths can be correlated to economic indices including per capita Gross National Product (GNP). The death rates along with 14 social economic indices in 28 sample countries were chosen to evaluate the relationship between transportation safety and economic development. Using multiple regression analysis, several models were developed to analyze the effect of economic factors on transportation safety. The results of the models developed showed that the death rate per 100,000 persons tended to increase when predicting the development of national transportation safety. As a result, advice is provided to macroscopically readjust and control the main social economic factors which include changing economic growth, enhancing economic strength, increasing technologic devotion and education training, and strengthening safety control to realize stable improvements in traffic and transportation safety.

The rate of incidents involving commercial vehicles is a particular concern in China, accounting for an estimated 35.8% of all crashes in 2004 and over 30% in 2005. Commercial motor vehicle safety issues in China were studied by collecting data from the Jingjintang freeway, which serves as the primary high-speed link between the cities of Beijing and Tianjin, China. For this study, heavy vehicles refer to vehicles with a gross weight of at least 20,000 pounds or vehicles designed to transport at least 40 passengers. This vehicle type is a surrogate for most Commercial Vehicles. Mid-sized vehicles are those with a gross weight between 10,000 to 20,000 pounds, or vehicles designed to transport 20 to 39 passengers. Light/compact-sized vehicles are those smaller than the mid-size. Commercial vehicles are over-represented in collision involvement, and crashes that involve commercial vehicles have a higher severity level. Data collected from a survey of commercial vehicle drivers was analyzed for statistical relationships between collision probability and causes related to driver behavior, driver training, and vehicle mechanical condition. Higher crash risk corresponds to lower driver experience, increased driver tendency to load a vehicle in excess of design capacity, operation of older or defective vehicles, and driver tendency to travel at excessive speeds. Based on the known factors influencing commercial vehicle crash probabilities, a number of potential safety countermeasures are suggested for further study in China.

In order to systematically analyze the trends in crash occurrence, Utah Department of Transportation (UDOT) has developed over the years a state-wide crash database and a GIS-based Data Almanac to search through the crash database as well as other databases including annual average daily traffic (AADT). The Data Almanac is a powerful search engine for extracting necessary crash data. Using the crash data provides one way to describe what has happened to the sections of highways that the analysts are evaluating. However, evaluating what might happen when improvements are made requires going one step further. The Interactive Highway Safety Design Model (IHSDM) developed by the Federal Highway Administration (FHWA), may be used to help the engineers conduct crash prediction and design consistency evaluation and intersection safety review as part of highway safety audits. This software provides an opportunity to design, operation, and safety engineers for evaluating sections of two-lane highways from various aspects and identifying most cost effective improvement alternatives to such audited sections.

Unascertained measurement theory (UMT) is used to create an evaluation method to determine the condition of cement concrete pavement (CCP). The proposed method allows for composite evaluation of the CCP that is consistent with the actual condition of the CCP. The resulting measurement model is designed to strictly adhere to UMT, the measurement functions are rigorously constructed, and a confidence criterion is introduced due to the ordered division the evaluation space. This paper also defines a method to determine index weight using similar weight by similar figures that provides an objective standard and avoids using the subjective opinions of experts when defining index weight. The index weight instead reflects the relative importance of the index in assessing of pavement maintenance quality. The proposed method is explained in detail by means of an example to encourage its use.

There are about 1,520 miles of multiple-lane (excluding freeway) highways in Louisiana that amounts to 9% of all highways on the Louisiana Department of Transportation and Development (LaDOTD) roadway system. However close to 50% of total crashes and 22% of total fatal crashes occur on multiple-lane highways annually. Reducing number of crashes on multiple-lane highways is crucial for LaDOTD. This paper investigates characteristics of crashes on multiple-lane highways in Louisiana and identifies the top sites for safety improvements by the network screening methods introduced by the on-going Highway Safety Manual projects. Classifying the multiple-lane highways by median (divided and undivided) and area (urban and rural), the results show that urban undivided highway is the most dangerous highway with the highest overall crash rate, and rural divided highways is the most fatal highway with the highest fatality rate in Louisiana. Unlike other types of highways, collisions with other vehicles consist of more than 70% of all crashes. Rear-end crash is the most common type of collision on this type of highways. The results from network screening reveal the characteristics of top ranking sites by four different methods.

Weaving areas in road interchanges are dynamic areas, where vehicles change lanes frequently to complete merging and diverging operations in a short distance. As a result, traffic flow is rather unpredictable and volatile, with negative impact on the safety and efficiency of the entire interchange. This paper studies the impact of weaving length on traffic safety and efficiency. An orthogonal experimental design is developed in order to analyze the relationship between traffic conflicts and (i) weaving length, (ii) traffic volume and (iii) ratio of weaving volume to mainline flow. A microscopic simulation model, VISSIM, is used to model the Youyi Avenue interchange of Wuhan Changjiang River Tunnel and extract the selected as the traffic safety indices for each scenario, i.e. traffic conflicts and conflict velocity. Finally, a reasonable weaving length for the interchange that balances traffic safety and efficiency is estimated using the difference analysis method.

Intersections are crash-prone locations due to the presence of conflicting vehicular movements. However, safety is not included in the intersection performance measure of level of service (LOS) for signalized intersections according to the current Highway Capacity Manual. The research presents the concept of safety level of service (SLOS) and develops model of SLOS for signalized intersections based upon vehicle conflicts, intersection geometrics, signal phasing, pavement markings, signage, pavement condition and ambient lighting. The average control delay of LOS is combined with risk index of SLOS to develop the delay and risk index for the improved LOS performance measure accounted for safety. In light of current LOS criteria and distribution of risk index values, the improved LOS criteria are defined for signalized intersections.

While investigating Jingjintang Expressway's traffic accidents, it is clear that, crash frequency and rates at interchange areas are more severe than that at other locations. To further explore the relationship between crash rates and characteristics of freeway geometric design features, this study analyzed the existing safety problems at Jingjintang Expressway's interchanges. Particularly we examined crash characteristics at ramps including length of acceleration lanes and deceleration lanes, ramp geometric design, traffic control devices at ramps and locations of toll plazas. The driver behavior and performance of overloaded trucks on ramps were also studied. The results of the study have clearly shown that it is important to have a uniform traffic information system and a consistent traffic control system. Most importantly, the study has concluded that the length requirements in our current design specification for ramp acceleration and decoration lanes are not sufficient for safety, particularly for large vehicles. A set of recommendations are made as a result of this study.

As public transport systems continue to modernize, China's implementation of Information Technology and Intelligent Transportation Systems will require a focus on increasingly complex data and technology issues. The success of these systems and the management of the underlying data are crucial to the support of China's current and future public transport services. This paper describes a business-technology planning approach used by leading-edge transit agencies in the United States (US) called "Enterprise Architecture Planning" or "EAP." EAP enables open-architecture, standards-based technology planning and deployment. By using an EAP approach, public transport agencies in China can define, document and coordinate the information technology requirements and implementation plans for mission-oriented business needs. By so doing, they can support local and national collaboration for increased efficiency and improved services to society.

This paper presents the application of data mining technologies for GPS positioning data uploaded by on-board intelligent public transit terminals to a data warehouse. The results provide a reliable reference for the application of increased intelligence to public transportation industry operation and management. This helps management to organize and guide public transportation operations, thus enabling the city public transportation to complete its operational plan and efficiently manage its daily operations by promoting more effective decision analysis.

Transit-oriented development (TOD) combines transit infrastructure with urban land utilization in ways that optimize the long-term benefits of urban mass transit (UMT). TOD has been successfully implemented in the USA, Europe, Singapore, Hong Kong and many other places; however, its practice in China is so uncommon that few people understand it well. Although it is worthwhile to study the foreign TOD models, Chinese cities cannot simply copy these examples because of how its politics, economic conditions, and regional cultures differ from the countries where TOD has previously been used. Chinese cities should analyze the successful TOD cases to determine how the various aspects of TOD apply to conditions existing in China and ultimately develop TOD designs and procedures appropriate for China.

Transit-oriented development (TOD) may soon become mandatory practice in China due to the rapid growth of traffic congestion in densely populated urban areas. Three core elements of TOD include transit, specific land development techniques and strategic organization of transportation systems. Well organized transportation systems provide transit, automobiles, cyclists and pedestrians with a contemporaneous environment and an attractive alternative to traffic congestion. Two key components include access management and nodal development. To investigate the three core elements of TOD, the Beiyuan Bus Rapid Transit (BRT) corridor in Jinan, China was taken as the study case. The study showed that it is most efficient to set dedicated pedestrian corridors at each end of the transit stations which are spaced on average 200 meters apart and set dedicated vehicle corridors between the pedestrian crossings. This planning strategy serves to delineate the separation of human and vehicle. An analysis model was developed to demonstrate that for each trip one minute can be saved using set dedicated cross pedestrian corridors at both ends of a station as compared to one end. The research followed the stipulations that traffic organization is consistent with BRT station design, the adjacent stations are considered together in one transportation system which means traffic organization is continuous along the corridor, and the existing land development is protected as possible through setting parallel vehicle corridors.

Quality delivery to Mega Projects is a growing vital concern to all owners, engineers and program managers. As the scale of projects increases, complexity of delivery increases leading to quality control problems. There are many examples out there which are well documented in technical papers as well as public press! This issue certainly leads to degrading public confidence in large complex projects. Rework needed to rectify defects leads to further increase in costs and time consuming litigations. In certain safety critical systems such as High Speed Rail Line, Nuclear Power Plants, Air-craft or Space vehicle construction etc. defect rate must be reduced to zero to avoid component failures which may lead to total system failure causing a lower performance, shutdown or even an accident.

This paper reports on the role of the Attica Tollway, an urban freeway connecting key Olympic venues, the airport, and the city of Athens in Greece, during the Athens 2004 Olympic Games. The paper details the measures taken by the operator of the freeway to ensure that Attica Tollway could fulfil the great challenges presented by this significant global event. It also discusses the lessons learned and performance indicators that justified the successful operation of the Attica Tollway during Games time. In light of the upcoming 2008 Olympic Games in Beijing, the goal of this paper is to present our experience regarding the preparation, management, and operation of a freeway for such a large-scale international event and thus to contribute to the understanding of the issues and challenges faced by this grand endeavour.

Freeways are the backbone of a highway system and they are designed to provide users with high standards of service. In order to maintain a high level of freeway service, adequate and appropriate maintenance should be routinely performed. Determining the need for, and the appropriate type of, routine maintenance may be accomplished with systematically performed, comprehensive evaluations of freeway maintenance quality. This paper summarizes a research project sponsored by the Ministry of Communications of China and the Highway Bureau of Jiangsu Province, which was to develop comprehensive evaluation procedures and models for freeway maintenance. The freeway in this system consists of six primary subsystems: pavement, bridge, subgrade, on-road facility, culvert, and roadside vegetation. Based upon survey and research, comprehensive evaluation models for the integrated estimation of maintenance quality of the six subsystems are set up by way of linear regression. Analysis of the correlation between the subjective evaluation of survey crews and objective evaluation of the models is carried out, and the result shows that the models are valid and reasonable.

Controlling traffic in cities is a very complex task, since efficient traffic flows require coordination of service requests from many participants. Traditional methods optimize signal timing plans, to maximize efficiency of traffic, based on predefined traffic flows e.g. fixed-time signal timing plans. Disadvantages of these methods are that they cannot cope with constantly changing traffic flows. Therefore, fixed-time signal timing plans are not robust enough to provide near-to-optimal service to fluctuating traffic flows. We propose a simple and feasible method which adjusts traffic lights to better utilize phase green splits. This method is based on detection of traffic flows and represents a form of actuated traffic control with a flexible phase sequence. The initial results show that self-adjusting traffic control significantly reduces average vehicle delays when compared with conventional traffic control. The method also shows some promising potential for coordinated traffic operations on urban arterials.

After several decades of decay and decline, the central cities in America have finally caught the attention of governments, the private sector, and ordinary citizens. There are numerous programs that entice businesses to relocate or stay in these areas. The programs also aim to improve the occupational and academic skills of local residents, encourage the creation and retention of new jobs, and encourage entrepreneurship and the formation of new businesses. However, congestion and parking problems continue to impede the progress of such downtown revitalization and economic improvement efforts. This manuscript documents a feasibility study of an Automatic People Mover (APM) application for the City of Newark in New Jersey. The objective of this feasibility study is to evaluate the applicability of the APM technology for increasing mobility, efficiency, and accessibility, and ultimately for enhancing transit service quality. The potential benefit of replacing the current LOOP, a small bus circulation system in downtown Newark, with APM technology, will not only reduce passenger walking, waiting, and overall travel time, but will also provide an anchor for downtown business development, which in turn will have great potential to stimulate economic development in the city of Newark and surrounding areas.

Since their inception in the U.S. in the 1970s, automated people mover systems have become numerous, with installations around the world. Because APMs are inherently complex systems that involve multiple interacting subsystems, new technology and public safety, it is essential to establish minimum standards for their design, construction, operation and maintenance. The paper describes the benefits of standardization to organizations that specify and procure APM systems, regulatory authorities, system suppliers, system operators, system users and the general public. The consensus approach to standard writing is described and evaluated in terms of fairness, objectivity and effectiveness. Balance in APM Standards Committee membership and openness and transparency of the standards creation process are evaluated. The scope of the APM standard and potential overlap with other related standards produced within other standards-developing organizations is discussed. The degree to which a standard can gain worldwide acceptance, having been developed by an American organization with global membership, is also considered.

One potential solution for the problem of annoying locomotive horn sound is a stationary horn mounted at the crossing. This "wayside horn" is sounded in place of the locomotive horn when a train approaches and is positioned to direct the sound precisely down the intersecting roadways rather than along the track. A wayside horn can therefore operate at a lower sound level than a locomotive horn and produce less area sound exposure. The objective of this project was to evaluate a wayside horn produced by Railroad Controls Limited. We conducted the evaluation through observation of a test installation in Rocky Mount before and after wayside horn installation. Before wayside horn installation, the site had a typical array of safety devices (gates, lights, signs, and marking). The site was a nearly ideal crossing of a road with one through lane in each direction of a single track with low train volumes and speeds in a moderate density suburban area. We examined the reliability of the system and also measured sound in the area, motorist behavior, motorist opinion, area resident opinion, and train engineer opinion. Based on the results from previous studies and the results from our test, the study team concluded that the wayside horn offers significant sound relief to residents and others in the area around a crossing. The team also concluded that the wayside horn has led to slight, if any, shifts in driver behavior and opinion. Finally, the study team concluded that the wayside horn appears to be reliable and acceptable to train engineers. The team strongly recommends that the NCDOT, other relevant agencies, and railroads continue to allow wayside horns and begin preparing policies and procedures to decide where they should be installed and who should pay for them.

This paper outlines a new set of criteria for the economic appraisal of railroad construction projects, based on overall comprehensive objectives including socioeconomic benefits. Multi-Criteria Analysis (MCA), in conjunction with Cost-Benefit Analysis (CBA), was deemed appropriate for analyzing and comparing these objectives. The proposed criteria are applied to the South Xinjiang Railroad project.

On June 15, 2007 a great tragedy occurred due to a ship collision with a bridge pier which resulted in nine fatalities in Guangdong Providence, China. This event greatly increased concern over the safety of bridges crossing navigable waterways. Due to the rapid expansion of highway networks in China many bridges which span rivers, lakes and crossing bays have been constructed or are under construction. At the same time, waterborne traffic has also been increasing which has caused an increased risk of ship collision with bridges (SCB). The risk analysis and management of SCB are vital to the safety of both bridges and ships. In this paper the risks of SCB are analyzed, evaluated, classified and rated according to their impact distribution, probability and loss of the accident. The risk acceptance criteria are analyzed and several kinds of ship collision protection methods are discussed. The framework of the "life-cycle cost oriented" risk reduction methodology is proposed to guide the bridge design and/or indicate the appropriate level of collision protection and management.

Effective incident management requires a full understanding of various characteristics of incidents to accurately estimate incident durations and to help make more efficient decision to reduce the impact of non-recurring congestion due to these accident. This paper presents a new prediction model base on the Bayesian decision model to estimate the traffic incident duration. The basic theory of Bayesian decision model is presented and the prediction model is created based on this theory using incident data collected in Rijkswaterstaat Verkeerscentrum Nederland from various sources. Compared to most existing methods, the proposed model is unique in two aspects: firstly, the model is adaptive in the presence of real incident for which data might only be partially available or in the presence of incomplete information. Secondly, this model is shown to perform better theoretical prediction accuracy compared to the decision model or Bayesian model.

Prompt and accurate incident response plan is an essential part of an effective freeway incident management system. However, uncertainties associated with the incident often lead to delayed or inaccurate response decision and processing plan. The core of the proposed algorithm is a Bayesian network based decision-making system that quantifies the causal dependencies between response decisions and incidents information. With input from real time incident data, the Bayesian networks update the probability of uncertainties associated with highway incidents through a two-way inference mechanism. We apply the proposed method to the incidents data recorded in Nanjing-Lianyungang freeway from 2001 to 2004 combined with more complete incidents data recorded in 2005 obtained from RK-IMS (a rule-based freeway incident management system). The model was validated using incidents data of the year 2006 from RK-IMS. The comparison results indicate that the proposed algorithm is accurate and reliable.

The paper analyzes elevated expressway off-ramp connections to arterial street intersection. Direct left-turns and U-turn left turns were analyzed in terms of travel time and delay. VISSIM 4.1 simulation models for direct left-turn and indirect left-turns were constructed. The simulation tests were executed under two traffic conditions. Delay and travel time of straight movements in the U-turn scenario were reduced by 40–90 percent, while delay and travel time of the direct left-turn increased. Research also showed traffic volume and composition can affect the results of this comparison.

An investigation on the effects of oxygen-enriched air on engine performance was proposed. This investigation focuses on combustion performance. As the oxygen concentration of the air for combustion increases, the heat of combustion for an engine of the same size would increase. The size (displacement) of an engine can be effectively reduced to achieve the same power. Oxygen- enriched air will affect the combustion process and the overall engine thermodynamics. For example, as oxygen concentration is increased, under the same operating conditions, combustion temperature and cylinder pressure will be increased. The purpose of this study was to quantify these results for a range of operating conditions. Results include detailed thermodynamic output of pressures and other properties as related to the oxygen concentration of the air used for combustion. Results also include engine performance parameters such as power, torque, fuel consumption, and thermal efficiency. In one case, the combustion performance of the engine was recorded for an equivalent load with different oxygen concentrations of air. For air enriched with 24% oxygen, the cylinder pressure was increased by about 15%, the heat of combustion increased, and both the maximum pressure and the increased heat of combustion were achieved more quickly. Other results were recorded.

Based on previous information about drivers' behavior, six types of driver Route Choice Behavior were studied. Using the VISSIM simulator, the effectiveness evaluation models of each traveler type was developed. The simulation-based model evaluated various types of guidance information; including dynamic route guidance using variable message signs (VMS), under the same travel demands. The results indicate that VMS can reduce travel time of related roads and VMS can markedly increase the network speed.

The advantages of mesh network provide huge potential for its application in transportation network security and first response service. The applications of mesh network in transportation security will not only improve emergency response but also help the coordination and integration across agencies, regions, and public safety and transportation disciplines. The goal of this paper is to explore the potential applications of mesh network in emergency response service and to analyze the performance of various emergency dispatching policies using simulations. The case study shows that with the help of mesh network and integrated management, promising saving in average response time and reduction in percentage of long response times can be achieved.

Flume experiments were performed to investigate the needed thickness of concrete mattress under wave action. Hydrodynamic pressures above and below the mattress were measured, and the mattress's stability was observed. Results indicate that the hydrodynamic wave pressure on the mattress accords well with cnoidal wave theory. Based on the theoretical analysis, an expression of the required thickness of a concrete mattress under wave action is proposed, which is mainly determined by wave height H, water depth h and wave period T. The theoretical coefficient of the semi-empirical formula was also predigested, according to the theoretical analysis.

Based on the fact that the speed of growth of the port capacity lags behind that of economic growth in China because of the shortage of investment in port facilities, the author deems that financing for port projects by asset-backed securitization (ABS) is a practical way to promote the investment. With the operation features of ABS taken into consideration and an analysis of the properties of port project in China made, a tentative design has been presented of the feasible modes of the financing for port projects by ABS in this paper.

Two-Way Stop-Controlled (TWSC) intersections are used widely. Capacity of vehicular traffic streams at TWSC intersections has been studied. This paper provides an improved procedure or model for determining TWSC intersection capacity based on traffic conflicts, for intersections with shared lanes and flared entries. The developed model was calibrated for conditions in China and can also assess the influence of non-motorized road users. The model results suggest that impact of non-motorized users on capacity of vehicular traffic can be appreciable.

With growing auto traffic and scarce land in most Chinese cities, parking guidance systems (PGS) are becoming increasingly valuable for reducing congestion and making efficient use of existing parking facilities. This paper contributes to the growing parking choice literature by proposing a two-phase parking model for pre-trip PGS with an application based on a parking behavior survey conducted in Nanjing, China. Our two-phase parking choice model simulates parking choice behavior in real-world situations; it searches all available parking options based on maximum acceptable walking distance to the driver's destinations, and selects optimal routes based on five criteria including distance, safety, convenience, cost, and accessibility. Our modeling approach can help drivers select optimal parking spaces with the benefit of detailed pre-trip route information.

All-Way Stop-Controlled (AWSC) intersections are used widely. Capacity of vehicular traffic streams at AWSC intersections has been studied. This paper provides an improved procedure or model for determining AWSC intersection capacity based on traffic conflicts, for intersections with shared lanes, short lanes, and flared entries. The developed model was calibrated for conditions in China and can also assess the influence of non-motorized road users. The model results suggest that impact of non-motorized users on capacity of vehicular traffic can be appreciable.

Mixed traffic is a remarkable character in our country, and therefore, a study on traffic composition is always one of the critical issues in the national traffic engineering field. In this paper, a concept of a large vehicle is used on a basic freeway section, investigated the real-time traffic flow to acquire parameters of vehicle type model. With the help of simulation software, we carried a study on how the 3 traffic flow parameters namely, density, speed and volume, change with the different large vehicle mix rates to find out the sensitivity analysis of large vehicle mix rate to traffic flow state parameters. Finally, we were able to determine the most unsafe large vehicle mix rate in a basic freeway section. The results from this paper are considered as a technical support to speed limits on freeway and traffic management decision system.

Some of the primary geotechnical and geometric issues considered in upgrading of a 12 km section of Hwy 40:34 situated in hilly terrain are presented and discussed. Steep grades, erosion, substandard curves, sharp shoulders, rock slopes, soft ground, wetlands, and the proximity of natural lakes to the highway were some of the features addressed in ensuring a satisfactory design and end product. This case study illustrates the importance of addressing geotechnical, geometric and construction issues simultaneously at the design stage, especially for highways in hilly terrain.

A method that integrates geographic information systems(GIS) with improved particles swarm optimization(PSO) for simultaneously optimizing three-dimensional highway alignments is presented in this article. With improved PSO introduced, the complex nonlinear alignments optimization problem becomes very simple to carry out. A GIS system —ArcGIS and its object-oriented data model — Geodatabase are exploited to store relevant geographic information and highway alignment elements. An example study shows that the proposed optimization gives more efficient results than the existing methods and also improves quality of solutions.

Based on the analyses of research findings from both domestic and abroad, Highway Three-Dimensional Dynamic Sight Distance (H3DSD) and methods for calculating it are put forward in this paper. Key techniques and basic characteristics for H3DSD are illustrated in detail. With the characteristics of second-order continuity, localization, flexibility, etc., cubic B-spline curve, as the prerequisite of calculation of H3DSD, is used to represent highway alignment. Meanwhile, the method for calculating highway geometry elements from GPS data is also provided. Using the relation of space geometry and vector, the calculation of H3DSD is done in 3D space. In the calculation, the drivers' dynamic visual angle, the limitation of the vehicle's headlights at nighttime, and the combination of horizontal and vertical alignment, etc. are taken into account. And a new method is provided to evaluate the consistency of highway alignment much more scientifically.

The concept of design consistency evaluation provides highway designers with a proactive tool for roadway safety improvement. Previous research has focused on the development of evaluation models for basic highway segments, while little research has considered interchange ramps. Interchange ramps differ from major roadways in the complexity of vehicles' acceleration and deceleration activities on them. The objective of this paper is to develop a practical consistency evaluation method for interchange alignments based on the theory of operating speed. To begin with, by giving a profound analysis of the moving characteristic of vehicles on ramps, the speed-change process on ramps is divided into five phases. Next, operating speed along highway ramps and speed differential between successive elements of ramps are calculated based on regression models developed by previous research. Three criterions are then established to evaluate the design consistency of ramp alignments. Lastly, a real life example is presented to illustrate the proposed method.

The Wuhekou Cable-Stayed Bridge has a central span of 370m, which features two towers, two cable planes, and a floated deck system. The 38.6m monolithic deck structure is the widest in China. The standard deck section is a fully pre-stressed concrete box girder, which is strengthened by spaced cross beams and longitudinal stringers, providing enough bending and torsion stiffness for this wide long-span girder. The deck was constructed using a balanced cantilever method with specially designed travelers, supported with a cable on each cycle during casting. Epoxy coated parallel strands and high performance concrete were used to improve the bridge's durability.

The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge. It takes the advantages of each and also makes up for some deficiencies of the two bridge structures, and therefore has better spanning capacity. By analyzing a cable-stayed-suspension hybrid bridge with main span of 1400 m, effects of design parameters including the cable sag to span ratio, the suspension to span ratio, the side span length, the layout of stay cable planes and the subsidiary piers in side spans etc on the wind stability are investigated. Utilizing 3D nonlinear aerostatic and aerodynamic analysis, and based on the wind stability, the optimal values of these design parameters are determined.

This study presents a systematic approach to determine the cable tension when vibration of the cable supports is taken into account. A dynamic model by including support vibrations was developed for cable structures. Boundary conditions were modeled with equivalent stiffness and mass. The displacement function was obtained from the model and then energy method was used to obtain stiffness and mass matrices to find the relationship between the cable tension and frequency. We studied several cases for ignoring support conditions and very large or very small equivalent stiffness values. In these cases the calculated cable tension was less than the actual tension and the accurate results were obtained when vibration of the supports were included in the model. Therefore, in dynamic analysis of cable structures, vibration of the supports should be included in the model.

A lack of reliable information on the location of underground utilities can result in costly conflicts, damages, delays, utility service disruptions, redesigns, claims and even injuries and lost lives during construction activities. While the location of subsurface utilities might be found on plans and records, experience has often shown that the utility locations are not exactly as recorded or the records do not fully account for the buried utility systems. An engineering process known as Subsurface Utility Engineering (SUE) has proven to be a welcome solution to providing this much-needed underground utility information. Combining geophysics, surveying, civil engineering, and nondestructive excavation technologies, SUE can provide accurate mapping of existing underground utilities in three dimensions during the design phase to avoid unnecessary relocations, eliminate unexpected conflicts with utilities, and enhance safety during construction. The use of SUE services has become a routine requirement on highway and bridge design projects, and is strongly advocated by the Federal Highway Administration (FHWA) and state departments of transportation. A savings of $4.62 for every $1.00 spent on SUE was quantified by the FHWA from a total of 71 projects. These projects had a combined construction value in excess of $1 billion. Qualitative savings were non-measurable, but it is clear that those savings are also significant and may be many times more valuable than the quantifiable savings. In addition to highway designs, SUE is gaining strong endorsement by other industries and market sectors, involved with design of construction projects involving congested underground utilities.

To assess the temperature field when microwave heating is used to recycle asphalt mixtures, a two-dimensional mathematic model considering the heat absorbed and conducted by microwave internal heat-generation was developed based on a Fourier heat transfer model. The microwave internal heat-generation was modeled by approximating the radial field by a two dimensional planar surface with uniform dielectric properties throughout. The control volume based finite difference method (CV-BDM) was used to establish a discrete form of the energy conservation equations, and a numerical simulation was conducted. Results showed that non-linear heat transfer. For confirmation, an experiment was conducted using a microwave power system at 2.45GHz and recording the temperature variation as a function of surface location and heating time within samples of asphalt mixture. The data confirmed that this microwave heating method could both heat the mixture in a reasonable time and improve temperature uniformity.

Instead of traditional polymer modifiers in asphalt, this experiment tested the addition of the common plastic bag (primarily LLDPE). Shredded plastic bags were added by percent weight for samples of 2%, 4%, and 6%. Softening point, penetration, ductility, low temperature-cracking performance and the micro-structure of the modified asphalt were studied. Analysis of the mixing process and structure of the modified asphalt indicated that swelling and molecular level crack-branching were the main reasons for the modified effect.

Asphalt treated base (ATB) materials have shown good road performance. There are some differences in the mix design methods used for ATB and Asphalt Concrete (AC) and this paper investigates four different design methods for ATB. Each design method is analyzed by using volume and mechanical indexes, and pavement performance. Based on this analysis, the proper design method of ATB is proposed.

The finite element analysis program, ANSYS, is utilized in this research to numerically assess the rutting depth of an asphalt pavement under selected loading conditions. A generalized Maxwell model is used to simulate the viscoelastic behavior of the hot mix asphalt. The viscoelastic parameters of asphalt materials are obtained using a Frequency Sweep Test. Excluding the hot mix asphalt, a Drucker-Prager model is utilized to simulate material behaviors of underlying pavement courses. Twenty-five selected cases are analyzed to better understand the effects of rutting for asphalt pavements. Factors considered in this study include the magnitude of wheel loading, the wander distance, the speed of wheel loading, the number of load repetitions, and the modulus of subgrade. The analysis results indicate that the magnitude of loading and the modulus of subgrade have the greatest impact on the rutting development followed by the factor of wander distance. The speed of wheel loading and the number of load repetitions are found to be insignificant in quantifying the rutting depth.

A new rutting prediction model for semi-rigid asphalt pavements is put forward based on the shear deformation mechanism. The most notable feature of this model is the efficient consideration of shear factors, namely, shear-strength is employed to evaluate the anti-deformation capacity of asphalt mixture and shear stress is used to represent the resistance of pavement structure to rutting. Four asphalt mixtures are used to carry out wheel tracking tests at different temperatures and contact pressures, and then the model is determined by the optimization analysis method. Meanwhile, the vehicle speed, which has a pronounced influence on rutting, is successfully introduced into the model by means of Boltzmann's linear superposition principle. Finally, the model is calibrated using accelerated pavement test results.

In China, the use of Sulfur Extended Asphalt Modifier (SEAM) has been recently introduced to the pavement community. This asphalt modifier does not only conserve energy, reduce asphalt content by 16%–40%, but also has good performance in terms of high strength and good rutting resistance. Preliminary experience with asphalt mixtures containing SEAM showed vulnerability to moisture damage. To improve upon resistance to moisture damage, large number of experiments was conducted, such as retained Marshall Stability, Freeze-thaw, and split test on four different types of aggregate, and five different types of anti-stripping agents. The influences of gradation, air void and asphalt content on reducing moisture damage due to the inclusion of SEAM were also analyzed. The improvement to different aggregate caused by different anti-stripping agent differs significantly. Using coarser gradation yielded higher resistance to moisture damage of mixtures containing SEAM.

Damage of asphalt mixes due to moisture is a complex phenomenon. Conventional moisture-related tests do not well simulate field conditions, in which traffic loading is an essential component. Flexural beam test has been widely used in current pavement design to evaluate material properties of asphalt mixes, but has not been well explored to study the moisture effect. This paper developed a typical fatigue-based test procedure for comparative evaluation of moisture sensitivity of different mixes. It is a controlled-strain flexural beam fatigue test performed at 20°C, 10 Hz, and 200με on specimens pre-saturated under 635 mm-Hg vacuum for 30 minutes and preconditioned at 60°C for one day. Test results showed that the fatigue based test procedure can distinguish mixes with different moisture sensitivities, and give a ranking of mixes consistent with prior field experience. An extension of the test procedure for use in the pavement design was also discussed, but further work is needed to implement the test procedure.

Compaction of asphalt mixtures in the laboratory is critical to meaningful results. Over the years several compactors were development to closely simulate field compaction. However, none of the devices or equipment was found to effectively compact asphalt mixtures. Therefore, a new automatic roller compactor (Turamesin) was developed which is able to compact any asphalt mixtures to the required slab thickness and density. The machine was developed by researchers from the Universiti Putra Malaysia under the Ministry of Science, Technology and Innovation. In this study Stone Mastic Asphalt (SMA) mixture was selected. The study was carried out in order to establish criteria for slab compaction and explore the potential of the newly developed Turamesin for use in SuperPave mix designs. A total of nine slabs were prepared with different combination of compactive efforts. Data was collected and analyzed to determine the appropriate values of the compactive efforts that results in optimum performance of the asphalt mixture. It was observed that to compact slabs of asphalt mixture to a design air void of 4%, a compactive effort of applied pressure of 8.0 kgf/cm², and 75 passes of roller were required.

This paper presents key findings of a research project which is entrusted with setting up guidelines for monitoring and evaluation of pavement performance requirements with the aim of improving durability and both road safety and environmental sustainability. The study has investigated some techniques for monitoring structural and surface characteristics of asphalt pavements, such as Ground Penetrating Radar, Falling Weight Deflectometer, Laser Profilometer, Skiddometer, and has addressed problems arising from the use of these techniques; the paper describes some measures needed to overwhelm them and for optimizing data collection procedures. In order to enhance the evaluation of asphalt pavements, the study has focused on data analysis and interpretation methodologies; it proposes refinements to the existing procedures for both data processing and interpretation.

Hot mix asphalt (HMA) covers more than ninety percent of paved roadways in the US. Most HMA pavement distresses (such as rutting and fatigue cracking) can be characterized through laboratory performance tests. The NCHRP Project 9-19 has identified several tests as the simple performance tests (SPT) to characterize the performance of HMA mixtures. The paper presents a laboratory study carried out by the Tennessee Department of Transportation and the University of Tennessee. One type of HMA commonly used as surface mixture in the state of Tennessee, USA, was evaluated through the simple performance tests of dynamic modulus and flow number. The Asphalt Pavement Analyzer (APA) test was conducted as comparison to the simple performance testing. The dynamic modulus was tested at 10, 25, and 54 °C and three confining pressures. Three asphalt binders (PG 64-22, PG 70-22, and PG 76-22) were used for comparative purposes. The results from the present study indicated that the simple performance tests generally agreed with APA, i.e., mixtures produced with increased high temperature PG grade of asphalt cement exhibited higher dynamic modulus values, higher flow number values, lower rut depths, indicating potentially high resistance to rutting.

Six thin asphalt pavements were tested under accelerated pavement testing. Those pavements generally varied in the base and subbase materials, but had the same layer thicknesses. Pressure cells and Multi-Depth Deflectometers were used to monitor the vertical stresses and plastic deformations developed inside the pavement structures. Falling Weight Deflectometer (FWD) tests were performed during the accelerated loading. Test results indicated that a test section with a furnace slag stabilized Blended Calcium Sulfate (or BCS, an industry waste material) base performed significantly better than its counterpart section with a fly-ash stabilized BCS base, whereas both BCS sections appeared to out-perform the pavement sections with the foamed-asphalt stabilized bases and the crush limestone bases. In addition, a cement-treated soil subbase was found to have a better load carrying capacity than a lime-treated subbase. Further investigation illustrates that both the FWD data and instrumentation results could reveal the structural deterioration fairly well.