Development of a Procedure for Using Surrogate Safety Assessment Model and VISSIM for Safety Assessment at Signalized Intersections
The primary objective of this study is to investigate the potential of using microscopic simulation models and Surrogate Safety Assessment Model (SSAM) for evaluating the safety performance of signalized intersections. A widely used microscopic simulation package VISSIM was used in this study to develop simulation models. The validity of using VISSIM and SSAM for traffic safety analysis at signalized intersections was tested by comparing the simulated conflicts to those measured in the field using traditional traffic conflicts techniques. Of particular interest was to identify if the consistency between simulated and observed conflicts could be improved by calibrating VISSIM simulation models and adjusting threshold values used for defining simulated conflicts in SSAM. A two-stage procedure was proposed in this study to develop, calibrate and validate VISSIM simulation models. It was found that the two-stage calibration procedure greatly improved the goodness-of-fit between simulated conflicts and real-world conflicts. After model calibration, the mean absolute percent error (MAPE) for total conflicts was reduced from 44% to 24%. More specifically, the MAPE value was reduced from 26% to 15% for rear-end conflicts, from 69% to 29% for crossing conflicts, and from 83% to 81% for lane-change conflicts. Linear regression models and the spearman rank correlation coefficient were also developed to study the relationship between simulated conflicts and observed conflicts. Data analysis results showed that there was a reasonable goodness-of-fit between simulated and observed rear-end and crossing conflicts. However, it was also found that the simulated conflicts generated by VISSIM and SSAM are not good indicators for traffic conflicts which are generated by unexpected driving maneuvers such as illegal lane-changes in the real world.
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Supplemental Notes:
- This paper was sponsored by TRB committee ANB20 Safety Data, Analysis and Evaluation
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Corporate Authors:
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Authors:
- Huang, Fei
- Liu, Pan
- Wang, Wei
- Huang, Jia
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Conference:
- Transportation Research Board 91st Annual Meeting
- Location: Washington DC, United States
- Date: 2012-1-22 to 2012-1-26
- Date: 2012
Language
- English
Media Info
- Media Type: Digital/other
- Features: Figures; References; Tables;
- Pagination: 18p
- Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD
Subject/Index Terms
- TRT Terms: Calibration; Signalized intersections; Traffic conflicts; Traffic safety; Traffic simulation
- Identifier Terms: Surrogate Safety Assessment Model; VISSIM (Computer model)
- Subject Areas: Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure;
Filing Info
- Accession Number: 01373706
- Record Type: Publication
- Report/Paper Numbers: 12-1966
- Files: TRIS, TRB
- Created Date: Jun 25 2012 2:41PM