Sze Chun Wong

Pedestrian safety is a critical concern, particularly in urban environments where pedestrian-related accidents constitute a significant proportion of road traffic accidents. In Hong Kong, a densely populated city, pedestrian fatalities accounted for 60% of all traffic deaths in 2022. To address this issue, a six-month trial of auxiliary devices that project a red light synchronized with pedestrian signals was initiated and installed at four selected pedestrian crossings. To evaluate the effectiveness of these devices, on-site video observation surveys were conducted before and after their installation, capturing the behavior of 20,080 pedestrians. Data analysis included Pearson’s chi-square tests and binary logistic regression models to assess the impact of these devices on pedestrian crossing behavior. The results indicate a negative correlation between the installation of these devices and the likelihood of pedestrian red-light running, with an observed reduction of over 25% in this unsafe crossing behavior. Based on these findings, this study recommends expanding the deployment of these devices at more signalized pedestrian crossings to improve pedestrian safety throughout the city. Priority locations for implementation include those with high accident rates, short or narrow crossings, and long pedestrian waiting times.

1. Since the seminal work of Merchant and Nemhauser (1978a, 1978b), the dynamic traffic assignment (DTA) problem has attracted considerable research attention. DTA comprises two fundamental compone...

This study investigates traffic dynamics on bidirectional undivided narrow roads. A novel heuristic-based passing (HP) model is proposed to microscopically model the complex passing maneuvers. Considering both perceived visual stimuli and steering imprecision, the model incorporates two heuristics that determine the driving direction and speed in the navigation of the most direct but unobstructed route. Real-world experiments analyzing the passing process of two vehicles on undivided narrow roads with varying widths were conducted. The results reveal that vehicles decelerated, veered toward the roadside to facilitate an oncoming vehicle’s passage and then readjusted to the center of the road, providing empirical support to the proposed HP model. In addition, as the road width increased, both the passing speed and clearance distance increased. The calibrated HP model could replicate the trajectories of the passing vehicles, demonstrating its accuracy. Real-world field observations were made at two undivided roads of varying widths and opposing traffic densities to investigate the macroscopic traffic patterns under the influence of lateral friction. The results showed that, on the undivided narrow road, when the traffic density in the travel direction was relatively low, the presence of high-density opposing traffic significantly reduced the speed of vehicles in the travel direction. Moreover, the proposed microscopic HP model well replicated the macroscopic traffic flow patterns. Overall, the results of this study enhance the understanding of traffic dynamics in the passing process on undivided narrow roads, offer insights for local road geometric design, and help identify sources of congestion evolution. Funding: This work was supported by the National Natural Science Foundation of China [Grants 72288101, W2411064, 72471077]; the Anhui Provincial Natural Science Foundation [Grant 2408085ME117]; and the Research Grants Council of the Hong Kong Special Administrative Region, China [Grants R7027-18, T32-707/22-N]. S. C. Wong was also supported by the Francis S. Y. Bong Professorship in Engineering. Supplemental Material: The online appendix is available at https://doi.org/10.1287/trsc.2024.0904 .