Reliability analysis of pedestrian safety crossing in urban traffic environment
ABSTRACT This paper describes the pedestrian safety crossing behaviour at signalized crosswalks in an urban traffic environment based on human reliability analysis. In our research, pedestrians’ waiting durations are modelled by a non-parametric and two parametric reliability models that recognize the effects of covariates. The covariates include pedestrian personal characteristics and urban traffic conditions in order to reflect the effects of human factors and internal environment comprehensively. The results indicate that most pedestrians show distinct time-dependent reliability but a few pedestrians are too impatient to wait for the lights changes.
SourceAvailable from: Xianglong LiuMathematical Problems in Engineering 01/2013; 2013:1-10. DOI:10.1155/2013/879752 · 1.08 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: In many cases, pedestrian crossing demands are distributed discretely along an arterial segment. Demand origins, destinations and crosswalks comprise a pedestrian crossing network. An integrated model for optimizing the quantity, locations and signal settings of mid-block crosswalks simultaneously is proposed to best trade-off the operational performances between pedestrians and vehicles. Pedestrian behavior of choosing crosswalks is captured under a discrete demand distribution. Detour distance and delay at signalized crosswalks are formulated as a measure of pedestrian crossing cost. Maximum bandwidths are modeled in analytical expressions as a measure of vehicular cost. To solve the proposed model, the Non-dominated Sorting Genetic Algorithm II (NSGA II) based algorithm is designed and employed to obtain the Pareto frontier efficiently. From the numerical study, it is found that there exists an optimal number of mid-block crosswalks. Excess available crosswalks may make no contributions to improvement in pedestrian cost when the constraint of the minimum interval between crosswalks and vehicular cost are taken into account. Two-stage crosswalks are more favorable than one-stage ones for the benefits of both pedestrian and vehicles. The study results show promising properties of the proposed method to assist transportation engineers in properly designing mid-block crosswalks along a road segment.Transportation Research Part B Methodological 03/2015; 73:103-121. DOI:10.1016/j.trb.2014.12.005 · 2.94 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Florida is the state with the highest pedestrian fatality rate per unit population in the U.S. In addition to engineering countermeasures, educational efforts directed to pedestrians and other road users are equally important for improving pedestrian safety. To explore educational formats and identify effective educational methods, the Florida Department of Transportation (FDOT) sponsored a pilot program called"Bulls Walk and Bike Week Campaign" on the Tampa campus of the University of South Florida (USF). A before-and-after comparison study was designed to evaluate the effectiveness of this campaign. In the study, observational surveys and a questionnaire survey were conducted to compare the surrogate measures of safety performance of the campus before and after the campaign. Observational survey outcomes show that roadway safety on campus improved after the campaign. The improvement is most siginificant for the site closest to the location where the majority of campaign activities took place. This suggests the necessity of seeking a spatial balance between concentrated and distributed campaign structures for optimal exposure to the campaign, especially when the budget of the campaign is limited and time is constrained. The analysis results of the questionnaire survey show that respondents as pedestrians, bicyclists, and drivers have different perceptions on driver yielding behaviors towards pedestrians and bicyclists. Contrasting points of view of different types of road users warrant careful and distinct designs of educational measures intended for different users. More respondents perceived that USF is a pedestrian/bicyclist-friendly campus after the campaign. It is suggested that a longitudinal survey should be conducted to follow up the effectiveness evaluation, and a cost-effective method should be further explored to continue the campaign efforts. (C) 2013 The Authors. Published by Elsevier Ltd.Procedia - Social and Behavioral Sciences 11/2013; 96:2756-2766. DOI:10.1016/j.sbspro.2013.08.309