The paper deals with transverse resistance problems occurring in railway ballast bed viewed from the standpoint of construction, maintenance, and safety of the railway track in use. Various ways of an analytical approach to the phenomenon tested using illustrative examples of mathematical models found in literature have been analyzed. A survey has been made into the current state of experimental works related to transverse resistances, and different methods of conducting such experiments in railway track during operation have been discussed. Furthermore, the idea of undertaking research, by a group of scientists from the Gdansk University of Technology, on the application of the tamping machine, is considered. Attention is focused on the process of preparing and carrying out the experimental works on transverse resistances, inclusive of an appropriate measuring system. The results of the experiments were analyzed and are included in the paper. The topic on how to deal with the time signals obtained from measurements and how to interpret them is discussed. The basic part of the paper is related to the theory of modeling the railway track structure paying special attention to the presented experimental work. An explanation has been provided to the mathematical description of the adopted model. The presented algorithm makes allowance for running simulation of the phenomenon on computer. The results obtained from simulation and experiments were aimed at convergence. Finally the results of such a simulation to enable a numerical description of the transverse resistance to the rail track ballast bed are tested.

The contribution of ballast and subgrade layers behavior to railway track performance is given insufficient consideration in the current railway track models. In particular, stress- and traffic-dependent characteristics need to be incorporated into the analysis. In this research, a new theoretical model is developed to include nonlinear characteristics of the track substructure such as resilient modulus and nonrecoverable strain, incorporating for the first time stress- and traffic-dependent properties of track sublayers. The new model uses a modified finite element plane strain technique which allows simulation of a three-dimensional load spread with a two-stage two-dimensional model. This technique keeps calculation time and cost to a minimum. Comprehensive field tests were conducted to evaluate the accuracy and reliability of the model. Challenging the current assumptions in the analysis and design of railway track systems, the impact of the consideration of the nonlinear properties of the ballast and subgrade materials on the accuracy of the theoretical results is discussed. The proposed technique was found to be accurate and easily applicable to railway track analysis.

In this paper a new method is presented for the estimation of actions on sleepers and the pressures that develop under the seating surface of the sleeper and are transmitted on the ballast. Results from laboratory tests performed on ballast are also presented. The tests were conducted in laboratories in France, Austria, and Greece, and resulted in the formulation of an equation describing the time evolution of ballast fouling. Moreover, a new method for the calculation of the actions on the railway superstructure is analyzed and compared with observations of tie cracking on railway track. The influence of the ballast stressing on track performance as derived from the tests and theoretical analysis is also discussed. Finally the empirical equation derived from laboratory tests is extended to include a relationship between the hardness of ballast and its expected life cycle due to fouling. Its validity is verified in a case study of ballast fouling.

Based on analysis of some existing prediction methods and models for track irregularities, according to the characteristics of track irregularity development for China railroad, this paper has proposed a short-range prediction model (SRPM) which applies the calculus thinking and method to estimate track irregularities over small track lengths on a single-day basis using track waveform data generated by track geometry car. We applied the SRPM to make predictions for track irregularities of many unit track sections of the up-going tacks of Beijing-Shanghai Railway Line (Jing-Hu Line) using the past two-year waveform data of this railway line. To confirm the efficiency of the SRPM, we compared the actual and estimated irregularities in both time and railway distance dimensions. The comparison shows that the SRPM can accurately predict track irregularities of unit track sections along Jing-Hu Railway Line on each day within a future short period.

Conditional priority is recognized as having the potential to improve transit service reliability at small cost to general traffic. The popular preference for conditional priority over unconditional priority encounters the challenges of various and challenging test scenarios. This paper makes a comparative analysis of unconditional and conditional priority in terms of intersection performance, based on the logic rule-based bus rapid transit signal priority (BRTSP), an active transit signal priority (TSP) for use at isolated signalized intersections with median bus-only lanes. Compared to previous study, the design of phase scheme, including two BRT phases, eight vehicle phases and four pedestrian phases, and the technical framework of BRTSP, centered on four categories of logic rules, have been improved to incorporate a mechanism for providing phase insertion, a special signal priority treatment in addition to green extension and early green. Phase insertion detector, if phase insertion is desired, is installed on the bus-only lane between check-in and check-out detector to trigger phase insertion request. A new category of logic rules, i.e., rules for early green response, is introduced into as a component of BRTSP to dynamically alter the response of the vehicle phases conflicting with the BRT phases to early green request. Inductive loop detector placed on each lane of the vehicle phases is used to monitor time headway and occupancy time on a lane by lane basis. The simulation experimental results indicated that: (1) phase insertion contributed substantially to late schedule deviations correction, but was recommended to be embedded in conditional priority rather than unconditional priority; (2) there was lack of convincing evidence that conditional priority had an inherent effectiveness of managing the intersection performance by varying the lateness criterion; (3) at TSP-enabled isolated intersections with green extension and early green, compared to having conditional priority, having an integration of unconditional priority and holding early BRT vehicles at control points may be a cost-effective solution not only to improve schedule adherence but also to accommodate the benefits of general traffic; and (4) at TSP-enabled isolated intersections with green extension, early green and phase insertion, there seemed to be a pressing need to move from unconditional priority to conditional priority.

The consumer electronics industry has made extensive use of the Bluetooth wireless protocol in many portable devices. A substantial number of these Bluetooth devices broadcast a unique identifier in the form of the media access control (MAC) addresses. These MAC addresses can be captured electronically and the same matching algorithms used in traditional license plate studies can be used to estimate segment travel time and origin-destination matrices. This paper briefly illustrates how these data can be used to estimate arterial link travel times and empirically illustrates the sensitivity of sample size to sensor placement. A controlled experiment with fixed lateral mounting and varying vertical mounting heights is then conducted to develop design recommendations for mounting Bluetooth monitoring devices. The paper concludes by recommending a Class I Bluetooth detector mounting height of at least 8 ft above the pavement grade. Based on a 24-h empirical data set on I-65 in Indianapolis, we found that 7.4% of the vehicles within $30^{\prime }$ and 6.6% of the vehicles between $102^{\prime }$ and $114^{\prime }$ had a discoverable MAC address.

The traffic volume and roadway capacity are the important basic inputs required for planning, analysis, and operation of roadway systems. Expressing traffic volume as number of vehicles passing a given section of road or traffic lane per unit time will be inappropriate when several types of vehicles with widely varying static and dynamic characteristics are comprised in the traffic. The problem of measuring volume of such heterogeneous traffic has been addressed by converting different types of vehicles into equivalent passenger cars and expressing the volume in terms of passenger car unit (PCU) per hour. The vehicles of highly heterogeneous traffic such as the one prevailing on Indian roads may occupy any convenient lateral position on the road, based on the availability of space, without any lane discipline. This study is concerned with the estimation of PCU values of vehicles in such traffic conditions, using microscopic simulation. The PCU values obtained for different types of vehicles, for a wide range of traffic volume and roadway conditions, indicate that the PCU value of a vehicle significantly changes with change in traffic volume and width of roadway.

Study of the basic traffic-flow characteristics and clear understanding of vehicular interaction are the prerequisites for highway capacity and level of service analyses and to formulate effective traffic regulation and control measures. Computer simulation has emerged as an effective technique for modeling traffic flow and to study the flow characteristics over a wide range of roadway and traffic conditions due to its capability to account for the randomness related to traffic. This paper is concerned with application of a simulation model of heterogeneous traffic flow, named HETEROSIM, to quantify the vehicular interaction, in terms of passenger car unit (PCU), for the different categories of vehicles, by considering the traffic flow of representative composition, on up-grades of different magnitudes for intercity roads in India. The PCU estimates, determined through microscopic simulation, for the different types of vehicles in heterogeneous traffic, for a wide range of grades and traffic volumes, indicate that the PCU value of a vehicle significantly changes with change in traffic volume and magnitude of grade and its length.

Sun glare may impair drivers’ vision on a particular road section while driving. Recently, a new method has been developed for analyzing the problem on specific road elements. This method does not account for the prolonged glare exposure, which occurs when the sun position lies uninterruptedly within the driver’s field of vision for an extended period of time along a highway segment. In this article a new methodology for carrying out the analysis of glare problems in road segments under conditions of prolonged glare exposure is presented. The methodology can be applied to both existing roads and new road designs, either for analyzing the impact of prolonged sun glare on drivers or for the design of measures against the sun’s glare. An application to a 45-km long road segment with east-west orientation is presented.

The heavy truck traffic generated by major seaports can have huge impacts on local and regional transportation networks. Both transportation agencies and port authorities have a need to know in advance the amount of truck traffic in order to accommodate them accordingly. Several previous studies have developed models for predicting the daily truck traffic at seaport terminals using terminal operation data. In this study, two kernel-based supervised machine learning methods are introduced for the same purpose: Gaussian processes (GPs) and $\epsilon$ -support vector machines ( $\epsilon$ -SVMs). They are compared against the multilayer feedforward neural network (MLFNN) model, which was used in past studies, to provide a comparison of their relative performance. The model development is done using the data from Bayport and Barbours Cut container terminals at the Port of Houston. Truck trips generated by import and export activities at the two terminals are investigated separately, generating four sets of data for model testing and comparison. For all test data sets, the GP and $\epsilon$ -SVM models perform equally well and their prediction performance compares favorably to that of the MLFNN model. On a practical note, the GP and $\epsilon$ -SVM models require less effort in model fitting compared to the MLFNN model. The strong performance of the GP and $\epsilon$ -SVM models and their relative ease of use make them viable alternative approaches to the MLFNN in port-generated truck traffic predictions.

The classification of secondary crashes is a useful performance measure of incident management systems. Previous classification methodologies used a static threshold for classifying secondary crashes. Such a threshold represents the spatial and temporal influence of a primary incident, such as 3.2 km upstream (2 mi) and 2 h after the incident. The dynamic methodology described herein improves upon existing static methodology by marking the end of the varying queue throughout the entire incident using incident progression curves. The four steps in the development of incident progression curves are: (1) processing of intranet incident reports; (2) filling in of incomplete incident reports; (3) nonlinear regression of incident progression curves; and (4) merging of individual incident progression curves into a master curve. The result from a 640 sample validation set shows that the dynamic methodology reduces Type I error by 24.38% and Type II by 3.13%. The application to a 5,514 freeway crash data set shows the results from using dynamic versus static methodology can differ by more than 30%.

Hot-mix recycled asphalt concrete in plant is one of the available techniques to perform cost and environmental effective pavement recycling. It is not commonly used in Portuguese paving practice basically because there is a lack of confidence at the end of the production chain. A study was conducted using mixtures from four trial sections, one with a traditional mixture for reference and three with 20, 30, and 40% of reclaimed asphalt concrete from a flexible pavement. The mix production was made in a batch plant without heating the reclaimed material. The laboratory process produced the same kinds of mixtures for comparison. Laboratory tests aimed to establish some fundamental properties for both the trial sections and laboratory mixtures: stiffness modulus, resistance to fatigue, and permanent deformation behavior. This paper contains the comparative results and indicates some useful directives for the use of such materials. It can be stated that for all the analyzed recycled mixtures the level of confidence should be similar to the one offered by the asphalt concrete produced from virgin materials.

Pavement Interactive (http://pavementinteractive.org) is an ongoing experiment in coupling a participatory web application with a unique data set to improve transportation engineering knowledge transfer. Specifically, Pavement Interactive is an online pavement community built on an open-source wiki platform where users can create, edit, browse, and search site content with just a computer, web browser, and internet connection. It contains 523 web pages and has logged just over 2 million page views in 3 years of existence. Data from Google Analytics over the past year show substantial and growing use worldwide. Observations of use indicate (1) primary use as a ready-reference and learning tool; (2) collaboration functions are possible but not extensively used; (3) substantial quality content attracts users; (4) participation drives success; (5) a majority of effort should be dedicated to content creation and participation; and (6) there should be a means to maintain currency for such websites beyond the funded development phase.

The common approach to estimate bus dwell time at a Bus Rapid Transit (BRT) station platform is to apply the traditional dwell-time methodology derived for suburban bus stops. Current dwell-time models are sensitive toward bus type and fare collection policy along with the number of boarding and alighting passengers. However, they fall short in accounting for the effects of passengers walking on a relatively longer BRT station platform. Analysis presented in this paper shows that the average walking time of a passenger at a BRT platform is 10 times more than that of a bus stop. The requirement of walking to the bus entry door at the BRT station platform may lead to the bus experiencing a higher dwell time. This paper presents a theory for a BRT network that explains the loss of station capacity during peak period operation. It also highlights shortcomings of present available bus dwell-time models suggested for the analysis of BRT operation.