Showing papers in "Transportation Research Record in 2019"
TL;DR: This study attempts to predict real-time crash risk by considering time series dependency with the employment of a long short-term memory recurrent neural network (LSTM-RNN) algorithm using the synthetic minority over-sampling technique (SMOTE).
Abstract: With the help of traffic detectors widely deployed along arterial roads and intersections, real-time traffic data are collected and updated in a very short time period, which makes it possible to c...
114 citations
TL;DR: In this article, a stated preference survey including a stated choice experiment was designed and conducted using a main mode choice multinomial logit (MNL) model and several submodels, regarding four transportation alternatives, namely private car, public transportation, autonomous taxi and autonomous flying taxi.
Abstract: Urban Air Mobility (UAM) is a recent concept proposed for solving the urban mobility problem,
such as urban traffic pollution, congestion and noises Before introducing UAM to the market,
demand could be evaluated by understanding the potential users’ choice behaviour regarding
current existing urban transportation modes and new autonomous transportation services, in
a hypothetical UAM environment This research intends to gain insight into the travel behaviour
impacts of autonomous transportation modes and notably, UAM, by deriving measures for
transportation service attributes and by identifying the characteristics of potential users who
are likely to adopt the autonomous transportation services, particularly the services of UAM
For this purpose, a stated preference survey including a stated choice experiment was
designed and conducted A main mode choice multinomial logit (MNL) model and several submodels
based on the profiles of the respondents were developed, regarding four transportation
alternatives, namely private car, public transportation (PT), autonomous taxi (AT) and
autonomous flying taxi (AFT)
The results indicate that travel time, travel cost and safety may be critical determinants of the
adoption of the autonomous transportation modes Moreover, the respondents having
relatively higher value of time (VOT) may be willing to pay more for using autonomous
transportation modes, especially the service of UAM The results also suggest that youngeraged
individuals and older-aged individuals with high income may be more likely to accept the
service of UAM In addition, the impact of trip purpose on the adoption of UAM was also
revealed through the examination of the survey results and the model analysis
93 citations
TL;DR: Road autonomous mobile robots have attracted the attention of delivery companies and policy makers owing to their potential to reduce costs and increase urban freight efficiency as mentioned in this paper. But their performance has not yet been evaluated.
Abstract: Road autonomous mobile robots have attracted the attention of delivery companies and policy makers owing to their potential to reduce costs and increase urban freight efficiency. Established delive...
90 citations
TL;DR: The study substantiates previous findings and advances knowledge of who is utilizing this new mobility option and what factors influence its adoption over public and active transportation modes and is intended to inform public policies ensuring that shared mobility technologies will complement existing multimodal landscapes and not worsen existing environmental concerns or equity gaps related to individual mobility.
Abstract: The recent and dramatic growth in ride-hailing activity is a bellwether of a coming transportation revolution driven by on-demand services. The impacts of ride-hailing services on the transportatio...
88 citations
TL;DR: The study findings are particularly useful, because they provide a first insight into performance of ML and DL models and it is surprising though that the Naïve Bayes model achieved a good performance despite being far less complex than other models.
Abstract: Although there are numerous studies examining the impact of real-time traffic and weather parameters on crash occurrence on freeways, to the best of the authors’ knowledge there are no studies whic...
74 citations
TL;DR: Empirical findings indicate that SVM provides higher prediction accuracy and outperforms the mixed logit model, and the ability of the three metaheuristics to enhance the SVM and the superiority of the harmony search algorithm in improving the performance of the S VM model is illustrated.
Abstract: Work zones are a high priority issue in the field of road transportation because of their impacts on traffic safety. A better understanding of work zone crashes can help to identify the contributin...
72 citations
TL;DR: In this paper, electric bicycles (e-bikes) are a new addition to bicycle-sharing and may improve its competitiveness and allow for higher speeds at a higher level of comfort than conventional bicycles.
Abstract: Electric bicycles (e-bikes) are a new addition to bicycle-sharing and may improve its competitiveness. E-bikes allow for higher speeds at a higher level of comfort than conventional bicycles and, c...
66 citations
TL;DR: Using data from the 2017 National Household Travel Survey, this article found that ride-hailing services have rapidly gained in popularity and grown extensively in the United States (U.S.). But, they did not provide a comprehensive analysis of ride-sharing services.
Abstract: Over the past few years, ride-hailing services have rapidly gained in popularity and grown extensively in the United States (U.S.). Using data from the 2017 National Household Travel Survey, this p...
62 citations
TL;DR: In this article, the information flow topology for a platoon of connected autonomous vehicles (CAVs) is described, where the CAVs communicate with each other via vehicle-to-vehicle (V2V) communications.
Abstract: Vehicle-to-vehicle communications can be unreliable as interference causes communication failures. Thereby, the information flow topology (IFT) for a platoon of connected autonomous vehicles (CAVs)...
61 citations
TL;DR: This study compares conflict indicators from a validity perspective by comparing crashes estimated from conflict indicators with observed crashes, and shows that traffic conflicts identified by the four indicators vary, with MTTC generating the most accurate crash estimates.
Abstract: Traffic conflict techniques have drawn considerable research interest and a number of conflict indicators have been developed. Previous studies have qualitatively analyzed indicator differences fro...
54 citations
TL;DR: In this article, the authors present an analysis of data from the 2017 National Household Travel Survey to examine the factors influencing the adoption and the frequency of use of on-demand ride-hailing services.
Abstract: This paper presents an analysis of data from the 2017 National Household Travel Survey to examine the factors influencing the adoption and the frequency of use of on-demand ride-hailing services su...
TL;DR: Interactions between the vehicles in the platoon show that the current SAE level-2 systems are not suitable for driving as platoons of more than typically three to four vehicles, because of instabilities in the car-following behavior.
Abstract: An increasing amount of vehicles are equipped with driver assistance systems; many of the vehicles currently on the market can be optionally equipped with adaptive cruise control and lane centering systems. Using both systems at the same time brings the vehicle to SAE level-2 automation. This means a driver does not need to perform longitudinal and lateral operational driving, although the driver should be ready to intervene at any time. While this can provide comfort, the interaction between vehicles operated by these systems might cause some undesired effects. This becomes particularly relevant with increasing market penetration rates. This paper describes an experiment with seven SAE level-2 vehicles driven as a platoon on public roads for a trip of almost 500 km. The paper discusses how the experiment was organized and the equipment of the vehicles. It also discusses the interaction of the platoon in traffic, as well as, in basic terms, the interaction between the automated vehicles. The experiences can be useful for other studies setting up field tests. The conclusion from this platoon test is: intentionally creating platoons on public roads is difficult in busy traffic conditions. Moreover, interactions between the vehicles in the platoon show that the current SAE level-2 systems are not suitable for driving as platoons of more than typically three to four vehicles, because of instabilities in the car-following behavior. © National Academy of Sciences: Transportation Research Board 2019.
TL;DR: Simulation results show that at high MPRs of truck platooning, the system mitigates congestion and increases throughput, at the expense of merging failures, and Evaluation of the three alternatives concludes that the yielding strategy is most effective in resolving the merging problem with Truck platooning.
Abstract: Truck platooning attracts considerable attention thanks to the promising fuel consumption benefits and business model. Nevertheless, concerns over the influence of long truck platoons on other traffic are raised by road operators. It is intriguing to understand under what conditions truck platooning will influence other traffic and what are the magnitudes of the influence. To this end, this paper reports a simulation study on examining the effects of truck platooning on freeway operations near an on-ramp. Systematic experiments were conducted with varying demand, market penetration rates (MPRs), intra-platooning gap, and platoon size. Moreover, three alternative strategies for truck platooning to accommodate merging traffic were tested: allowing courtesy lane change of trucks, active yielding, and keeping a larger intra-platoon gap than the acceptable gap for human drivers to change lane. Simulation results show that at high MPRs of truck platooning, the system mitigates congestion and increases throughput, at the expense of merging failures. The merge location distributions shift toward the end of the acceleration lane at congested flow and high MPRs. The effect on average merging speed is insignificant, but the merging speed in saturated traffic with truck platooning shows larger variability. At free flow and low MPRs, the influence is insignificant. Evaluation of the three alternatives concludes that the yielding strategy is most effective in resolving the merging problem with truck platooning. Courtesy lane change is not always possible because of the high speed difference between lanes and keeping a larger time gap suppresses the benefits in congestion mitigation and throughput increase.
TL;DR: There is a statistically significant difference between human drivers’ behavior in these two scenarios and human drivers felt more comfortable following the AV, suggesting the importance of capturing changes in human behavior in microscopic simulation models of mixed driving environments.
Abstract: Despite numerous studies on general human–robot interactions, in the context of transportation, automated vehicle (AV)–human driver interaction is not a well-studied subject. These vehicles have fu...
TL;DR: In this article, the results from a recent consumer survey were analyzed in relation to willingness to adopt and willingness to pay (WTP) for different autonomous vehicle (AV) features.
Abstract: Results from a recent consumer survey were thoroughly analyzed in relation to willingness to adopt and willingness to pay (WTP) for different autonomous vehicle (AV) features. Four different levels...
TL;DR: An adjacent-frame fusion method for vehicle detection and tracking in complex traffic circumstances is presented and, compared with the previous research, objects can be detected and tracked without object model extraction or a bounding box description.
Abstract: The problem of traffic safety has become increasingly prominent owing to the increase in the number of cars. Traffic accidents often occur in an instant, which makes it necessary to obtain traffic ...
TL;DR: The regression results reveal that weather factors, including temperature and wind speed, significantly affect e-bike share usage and it was found that weekends, summer months, high population density, proximity to public transit centers, recreational centers, and bike trails positively affect the demand for e-bikes.
Abstract: In recent years, bike share programs have become more popular as they contribute to the move toward sustainable mobility in cities. Electric bike sharing, however, remains in the early stages of de...
TL;DR: An extreme value theory approach is applied to evaluate the safety effects of converting channelized right-turn lanes into smart channels, based on traffic conflicts defined by time to collision and collected from three treatment intersections and one control intersection in the city of Penticton, British Columbia.
Abstract: Because of well-recognized quality and quantity problems associated with historical crash data, traffic conflict techniques have been increasingly used in before-after safety analysis in recent yea...
TL;DR: In this article, a new approach for vehicle classification using roadside LiDAR sensor is presented, which extracts six features (one feature, object height profile, contains 10 sub-features) extracted from the vehicle.
Abstract: This research presented a new approach for vehicle classification using roadside LiDAR sensor. Six features (one feature, object height profile, contains 10 sub-features) extracted from the vehicle...
TL;DR: In this paper, the potential and suitability of different fractions of reclaimed asphalt pavement for roller compacted concrete pavement (RCCP) mixes is evaluated. Natural coarse and fine agg...
Abstract: The present study evaluates the potential and suitability of different fractions of reclaimed asphalt pavement (RAP) for roller compacted concrete pavement (RCCP) mixes. Natural coarse and fine agg...
TL;DR: This paper proposes a novel method for the estimation of queue lengths, probe vehicle penetration rates, and traffic volumes at signalized intersections, and testing results have shown that the method is ready for large-scale real-field applications.
Abstract: With the development of connected vehicle technologies and the emergence of e-hailing services, a vast amount of vehicle trajectory data is being collected every day. This massive amount of traject...
TL;DR: A data fusion process is employed to gain deeper insights about the characteristics of ride-hailing trips and their users to better understand the use of these services.
Abstract: The rise of ride-hailing services has presented a number of challenges and opportunities in the urban mobility sphere. On the one hand, they allow travelers to summon and pay for a ride through the...
TL;DR: A lightweight microsimulation free-flow acceleration model (MFC) is proposed that is able to capture the vehicle acceleration dynamics accurately and consistently, it provides a link between the model and the driver and can be easily implemented and tested without raising the computational complexity.
Abstract: Free-flow movement of vehicles in microsimulation software is usually defined by a set of equations with no explicit link to the instantaneous dynamics of the vehicles. In some cases, the car and t...
TL;DR: State highway agencies recognize the environmental and economic benefits of utilizing reclaimed asphalt pavement (RAP) in asphalt mixes as discussed by the authors, and most agencies assume all of the RAP binder conten...
Abstract: State highway agencies recognize the environmental and economic benefits of utilizing reclaimed asphalt pavement (RAP) in asphalt mixes. Currently, most agencies assume all of the RAP binder conten...
TL;DR: In this paper, the authors investigated the performance of eighteen different dense-graded asphalt mixtures paved in Missouri using a wide range of reclaimed asphalt pavement (RAP) and recycled asp...
Abstract: This study investigates the performance of eighteen different dense-graded asphalt mixtures paved in Missouri. The sections contain a wide range of reclaimed asphalt pavement (RAP) and recycled asp...
TL;DR: In this article, the emergence of autonomous vehicles (AVs) may shape the future landscape of urban mobility, and there is a growing literature on public opinions with regard to self-driving.
Abstract: The emergence of autonomous vehicles (AVs) may shape the future landscape of urban mobility. Although there is a growing literature on public opinions with regard to self-driving, little attention ...
TL;DR: A joint traffic signal optimization algorithm is proposed which utilizes connected vehicle (CV) information to identify optimum signal timing and phasing plans while also providing speed guidance to individual vehicles to minimize total number of stopping maneuvers.
Abstract: A joint traffic signal optimization algorithm is proposed which utilizes connected vehicle (CV) information to identify optimum signal timing and phasing plans while also providing speed guidance t...
TL;DR: A self-driving, fully automated, or "autonomous" vehicle (AV) revolution is imminent, with the potential to eliminate driver costs and driver error, while ushering in an era of shared mobility as mentioned in this paper.
Abstract: A self-driving, fully automated, or “autonomous” vehicle (AV) revolution is imminent, with the potential to eliminate driver costs and driver error, while ushering in an era of shared mobility. Dyn...
TL;DR: The findings suggest that ADTS adopters are likely to prefer this mode for long-distance leisure trips rather than short-distance commuting trips, and conventional cars and public transportation are perceived as being the least attractive alternatives on short- and long- distance commuting trips.
Abstract: Because of technology penetration in the transportation system, the automated vehicle (AV) is set to be a future mode of transport. Given the major implications of AVs, investigation of the potenti...
TL;DR: A novel bi-level random forest approach is proposed to predict passenger train delays in the Netherlands and shows that the proposed model provides the best prediction accuracy compared with other alternatives.
Abstract: Accurate near-term passenger train delay prediction is critical for optimal railway management and providing passengers with accurate train arrival times. In this work, a novel bi-level random fore...