Highlights This paper develops SPFs at different aggregation levels for freeways by using microscopic traffic detector data. The effects of average speed and speed variation on crash frequencies are revealed at different aggregation levels. The time-of-day operation status of HOV lanes is introduced to the disaggregated SPFs. The safety performance of HOV lanes at different aggregation levels are evaluated and compared. The transferability of SPFs at different aggregation levels between Florida, Virginia, and California is evaluated.

    Abstract Safety Performance Functions (SPFs) have been widely used by researchers and practitioners to conduct roadway safety evaluation. Traditional SPFs are usually developed by using annual average daily traffic (AADT) along with geometric characteristics. However, the high level of aggregation may lead to a failure to capture the temporal variation in traffic characteristics (e.g., traffic volume and speed) and crash frequencies. In this study, SPFs at different aggregation levels were developed based on microscopic traffic detector data from California, Florida, and Virginia. More specifically, five aggregation levels were considered: (1) annual average weekday hourly traffic (AAWDHT), (2) annual average weekend hourly traffic (AAWEHT), (3) annual average weekday peak/off-peak traffic (AAWDPT), (4) annual average day of the week traffic (AADOWT), and (5) annual average daily traffic (AADT). Model estimation results showed that the segment length and volume, as exposure variables, are significant across all the aggregation levels. Average speed is significant with a negative coefficient, and the standard deviation of speed was found to be positively associated with the crash frequency. It is noteworthy that the operation of the high occupancy vehicle (HOV) lanes was found to have a positive effect on crash frequency across all the aggregation levels. The model results also showed that the AAWDPT and AADOWT models consistently performed better (the improvements range from 3.14%–16.20%) than the AADT-based SPF, which implies that the differences between the day of the week and peak/off-peak periods should be considered in the development of crash prediction models. The model transferability results indicated that the SPFs between Florida and Virginia are transferrable, while the models between California and the other two states are not transferrable.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Developing safety performance functions for freeways at different aggregation levels using multi-state microscopic traffic detector data


    Beteiligte:
    Yuan, Jinghui (Autor:in) / Abdel-Aty, Mohamed (Autor:in) / Fu, Jingwan (Autor:in) / Wu, Yina (Autor:in) / Yue, Lishengsa (Autor:in) / Eluru, Naveen (Autor:in)


    Erscheinungsdatum :

    2021-01-04




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Safety Assessment Model for Multilane Freeways using Loop Detector Traffic Flow Data

    Wei, Jun / Yao, Hongwei / Tian, Xiaoyan et al. | ASCE | 2015


    Assessment of Level of Service on Freeways by Microscopic Traffic Simulation

    Geistefeldt, Justin / Giuliani, Stefan / Vortisch, Peter et al. | Transportation Research Record | 2014


    Applicability of boosting techniques in calibrating safety performance functions for freeways

    Yehia, Ahmad / Wang, Xuesong / Feng, Mingjie et al. | Elsevier | 2021


    Safety Performance Functions Reflecting Categorical Impact of Exposure Variables for Freeways

    Kim, Ducknyung / Kim, Dong-Kyu / Lee, Chungwon | Transportation Research Record | 2013


    Real-Time Lagrangian Traffic State Estimator for Freeways

    Yufei Yuan, / van Lint, J. W. C. / Wilson, R. E. et al. | IEEE | 2012