Traffic accidents are among the top 10 causes of death worldwide. They resulted in over 1.3 million fatalities in 2012 alone and cause billions of dollars of loss each year in productivity, property damage, and time and fuel due to congestion. Traffic safety is becoming increasingly important, particularly in developing countries that are facing rapid urbanization and motorization. In addition to traffic safety, there are many recent examples of transportation systems being disrupted by extreme weather events. Transportation activities, on the other hand, also contributed substantially to these extreme weather events either directly or indirectly. Clearly, it is important to build a resilient and sustainable transportation system that is less vulnerable to disasters and has the minimum possible environmental footprint.
In this special issue, several studies investigated highway transportation from the operations, resiliency, and logistics perspectives. X. Zhang et al. developed a cooperative Q-learning algorithm for finding near-optimal path sets for multiple Origin-Destination (OD) pairs simultaneously. The new algorithm was compared with the
Given the rapid development of high-speed rail in China, the aging rail infrastructure in developed countries, and many high-profile rail accidents, railroad safety has been receiving increasing attention globally. P. Xu et al. developed a railroad track condition prediction model and demonstrated its accuracy and robustness using track geometry data. L. Song et al. focused on analyzing the safety and reliability of high-speed Electric Multiple-Unit (EMU) trains. They integrated Fault Tree Analysis (FTA) and Petri nets and demonstrated their effectiveness in analyzing the failure modes of pantograph of high-speed EMU trains. J. Ye et al. proposed an improved Optimal Velocity (OV) car-following model for moving-block train control. Compared to the conventional OV car-following model, the improved OV model takes into consideration uncertainties in distance headway measurements and generates safer and more stable train control performance.
Extreme weather events have caused many airline flight disruptions. B. Zhu et al. developed a two-stage stochastic model to optimize the recovery process of airline flight disruptions. The first stage adjusts flight schedules to minimize delay and flight cancellation cost. The second stage focuses on minimizing aircraft rerouting cost. The authors also developed a simulated annealing algorithm to solve the two-stage model. G. Duan et al. focused on aircraft crash modeling. They improved the Functional Resonance Analysis Method (FRAM) by integrating it with model checking, which allows researchers to use the FRAM for identifying and simulating all possible ways that a hazard factor may lead to accidents. They demonstrated the enhanced FRAM’s effectiveness by applying it to analyze a two-aircraft crash in Italy.
Public transit plays a major role in battling traffic emissions and global warming. To make public transit more attractive, it is important to have well-developed transit assignment models for optimal transit network design. S. Luo et al. investigated the independence between the travel times of adjacent transit links, which has been implicitly assumed to be independent in most transit assignment methods. They developed a method to determine the validity of the travel time independence assumption. They also proposed a capacity-restraint assignment method to handle the case where the travel time independence assumption is invalid.
This special issue includes a broad range of topics related to safe, resilient, and sustainable transportation systems. We received 47 manuscripts and 14 of them were accepted for publication, covering highway, rail, air, and transit modes.
We would like to sincerely thank all authors who contributed their papers to this special issue. Also, we are extremely grateful to all reviewers for their time and outstanding work, which are critical to the success and quality of this special issue.