A metro station island platform in China takes a high density of passenger flow. For security and energy reasons, most metro stations have installed fully enclosed and semienclosed platform screen doors (PSDs), which causes passengers to gather into clusters in front of the screen doors to await the train rather than distributing randomly and evenly on the platform. This paper proposes a new waiting area division method on a metro station island platform, which can obviously improve the evaluation of the level of service at such stations and the accuracy of simulation software. The paper first analyzes the changes in waiting behavior after the installation of PSDs and the regional function transition during the three processes of waiting, alighting and boarding, and dissipation. Then, by means of video identification and field observations during the peak hours (7–9 a.m. and 5–7 p.m.), determines the shape of the waiting area to be a rectangle on the basis of the distribution pattern of passengers on platform. In addition, the paper presents the notion that the size of the waiting area varies with the different volume of waiting passengers and thereby establishes and validates the mathematical models for length and width of the single waiting area, which concludes that the waiting area width model is in the form of a logarithmic function and the length model is in the form of a power function. Finally, it shows the practicality of the new method in the level of service (LOS) evaluation and simulation accuracy. The result verifies that the new proposed method can truly reflect the feelings of waiting passengers and provide a significant basis for platform operation management. According to comparisons, the traditional method evaluating the whole platform LOS is overly optimistic, whereas the proposed method based on a separate waiting area can truly reflect the feelings of waiting passengers. In the simulation software Legion, the precise division of the platform waiting area with installation of PSDs improves the accuracy of the simulation results.

From the historical bus trajectories, it was found that the headway bias amplified as buses travel on the route. When controls on buses are unavailable, the following buses will maintain the movement tendency toward their previous one, whether being closer to, farther away, or stable, judged by the running state in which buses fall. A tendency-based model for link travel time estimation was proposed, and three tendency-based corrections were introduced in the model, which are the long-term tendency, the short-term tendency, and the combined-term tendency. Then, contrast experiments were conducted in which the boundary of the running state is a control variable to show the performance of the tendency-based model under different boundary values. The experiment results show that, with the increase of the boundary value, the degree of improvement of the tendency-based mode to the historical data–based model first increases, then decreases, and converges to zero finally. The optimal boundary value for the tendency-based model was calibrated, judged by the net number of trips improved and net mean absolute error reduced, and the results show that the long-term and the combined-term tendency-based models have a lower optimal boundary and higher optimization potential, and are faster to be steady enough, which made the short-term tendency-based model less competitive.

Variable speed limit (VSL) can be used on freeways to manage traffic flow with the goal of improving capacity. To achieve this objective, it is necessary that both speed and density dynamics be represented accurately. In this study, to deeply understand the effectiveness of VSL control, an analytical model was developed to represent drivers’ response to updated speed limits and macroscopic speed dynamical change with respect to changeable speed limits. Specifically, to model the freeway links having VSL control, the fundamental diagram (FD) was replaced with the VSL control variable in the relaxation term of the METANET. This modification led to the speed control variable appearing linearly, which is preferable for online computation. The density dynamics are based on the cell transmission model (CTM), which is introduced to estimate the transition flow among successive links with some practical constraints. It also offers flexibility in designing active bottleneck in which there is a capacity drop once feeding flow exceeds its capacity. To exploit this benefit, a modification was introduced in the FD of the density dynamics. A VSL control strategy was proposed that explicitly considers traffic characteristics at active bottleneck and its upstream-downstream segments. It can control traffic flow into any type of active bottleneck. Then, the proposed traffic dynamics with the control strategy are implemented in a freeway corridor using the model predictive control (MPC) approach. The analysis was carried out in the calibrated microsimulation model, VISSIM, within a scenario in which shock waves were present. The microsimulation model functions as a proxy for the real-world traffic system. This study reveals that, in terms of mobility, VSL is mostly effective during congestion periods.

An auxiliary through lane (ATL) is a commonly used congestion relief measure at signalized intersections in which fiscal and right-of-way constraints do not allow for full widening between intersections. Previously developed models have predicted the flow in the ATL as a function of macroscopic elements, such as through-movement demand and the ratio of average green time to cycle length. However, these models explain neither driver behavior nor motivation to use the ATL, nor can such an approach be used in microscopic simulation models. This paper presents empirically developed models for driver lane choice at signalized intersection approaches with one ATL and one continuous through lane (CTL). These models were developed from a calibration data set that covers eight ATL approaches in three U.S. states, for a total of 12 h of observation. The results suggest that the utility of the ATL is a function of each through-movement driver’s arrival time (during either the effective red or green phase), and the queue lengths in either lane at the time of arrival. After calibration, the models were evaluated by applying them to data from a validation site from outside the calibration data set. The paper concludes with a discussion of how the models should be implemented within the lane-change algorithms of microsimulation systems.

Weather information is frequently requested by travelers. Prior literature indicates that inclement weather is one of the most important factors contributing to traffic congestion and crashes. This paper proposes a methodology to use real-time weather information to predict future speeds. The reason for doing so is to ultimately have the capability to disseminate weather-responsive travel time estimates to those requesting information. Using a stratified sampling technique, cases with different weather conditions (precipitation levels) were selected and a linear regression model (called the base model) and a statistical learning model [using support vector machines for regression (SVR)] were used to predict 30-min-ahead speeds. One of the major inputs into a weather-responsive short-term speed prediction method is weather forecasts; however, weather forecasts may themselves be inaccurate. The effects of such inaccuracies are assessed by means of simulations. The predictive accuracy of the SVR models show that statistical learning methods may be useful in bringing together streaming forecasted weather data and real-time information on downstream traffic conditions to enable travelers to make informed choices.

Truck travel, normally expressed in terms of truck vehicle-distance travel (VDT), is a critical data requirement for the design, construction, operation, and management of rural highway systems. The need to estimate and characterize truck travel on a system-wide basis, yet retain a compatible, site-specific mining capability, challenges the traditional approach of traffic monitoring programs. This paper develops and applies a two-phase methodology to estimate truck VDT on rural highway systems. The first phase, which leverages the approach recommended for developing truck traffic data inputs for mechanistic-empirical pavement design, processes vehicle classification data obtained from continuous, sample, and manual counts into annual average daily truck traffic (AADTT) estimates by vehicle class. The second phase attributes these site-specific AADTT estimates to highway segments comprising a rural highway network. The methodology, which is transferrable across jurisdictions, integrates standard statistical procedures with engineering judgment and trucking industry intelligence by establishing transparent decision algorithms and criteria. Application of the methodology using real data reveals relevant limitations and illustrative results that have application to a wide range of transportation engineering decisions.

Recurring congestion at signalized intersections is caused by the inability of traffic signal controls to serve demand even in cities where advanced traffic signal timing and management systems are in operation. Left-turn prohibition (LTP) and partial grade separation with low-clearance underpass (LCUP) are possible congestion mitigation actions for urban complex and congested signalized intersections that have exhausted other options for capacity enhancement, such as lane addition and signal timing optimization. LTP and LCUP improve traffic signal efficiency by eliminating signal phases, increasing green splits, or adding lanes. They also improve intersection safety by eliminating certain conflicts. At the same time, they necessitate traffic rerouting, may have negative impacts at downstream locations, and may have perceived or actual impacts to accessibility and neighborhood character. A planning-level assessment method to quantify and compare the benefits and costs LTP and LCUP was developed to examine the potential feasibility of these congestion mitigation actions prior to conducting, e.g., extended data collection, detailed analysis, simulation, evaluation, and public meetings. The assessment considers intersection delays, accident frequency, and cost-benefit analysis based on industry publications. The proposed method uses standard methodology and nationally accepted default values and conservative assumptions to expedite assessment by minimizing the number of required inputs. Due to the complexity of analysis for LTP and LCUP for various time periods and multiple locations, a spreadsheet-based tool was developed. A case study demonstrates the combined use of travel time, safety, and economic savings of the proposed method.

Transportation has contributed to climate change and will most likely be impacted by changes in sea level, temperature, precipitation, and wind, for example. As the risk of climate change impacts become more imminent, pressure for adaptation within transportation agencies to address these impacts continues to rise. The most logical strategy is to integrate consideration of adaptation projects into the long-range transportation planning (LRTP) process. To do this, tools and experience are needed to assist transportation agencies. The Climate Change Adaptation Tool for Transportation (CCATT) is a step-by-step method to evaluate climate change scenarios and impacts, inventory at-risk existing and proposed infrastructure, and assess mitigation practices to identify supporting adaptation efforts. This paper focuses on the application of CCATT to the Mid-Atlantic region using a case study on the Wilmington Area Planning Council (WILMAPCO), the Metropolitan Planning Organization for northern Delaware. The results of the application and case study demonstrate the importance of climate change adaptation practices in long-range transportation planning.

Prestressed concrete (PC) track beams are the important component of straddle monorail transit systems. To ensure the normal operation of straddle monorail transit, a type of prefabricated steel track beam, termed an emergency track beam (ETB), is used for rapid replacement of destroyed PC track beams. The object of this paper is to analyze the design of ETB alignment to satisfy the rapid replacement of PC track beams for all types of alignments. This paper describes the structural design and replacement principles of ETB. According to an analysis of six types of PC track beam segment alignments, two types of circular curves, $R_e=\infty$ and 180 m, are considered as the ETB plane curve, a straight line is considered as the ETB vertical curve, and superelevation can be achieved by a cast-in-place concrete layer over the running panel of the ETB. The writers quote PC track beams in Chongqing, China, for instance analysis to verify the alignment design of ETBs. The paper also presents the typical cost and construction process of ETBs in Chongqing. This paper shows that ETB structural and alignment design can fulfill the requirement of rapid replacement of PC track beams.