01506188

Component

http://onlinepubs.trb.org...nces/2011/RSS/2/Yang,H.pdf

Road safety is a critical issue for transportation systems. The use of crash data-based methodologies to analyze traffic safety problems has been problematic due to shortcomings such as unavailability and low quality of historical crash data. Other than crash data-based analysis, development of micro-simulation models in conjunction with surrogate safety measures has been shown to complement traditional safety analysis. However, for the adopted simulation model to achieve high fidelity, it is important to calibrate and validate it before use. This paper proposes a numerical optimization approach to calibrate a traffic simulation model for rear-end traffic conflict risk analysis on highways. The proposed calibration approach is developed based on the stochastic gradient approximation algorithm to find optimal parameters of stochastic traffic simulation models. The calibration methodology accounts for multiple calibration criteria and is implemented on a selected traffic simulation platform to test its performance. Simulated operational measurements and traffic conflict risk in terms of surrogate safety measures are quantified and compared with observations derived from real-world vehicle trajectory data from the Next Generation Simulation (NGSIM) program. The calibrated traffic model has been validated by using independent vehicle trajectory data saved as a hold-out sample. The results show that the fine-tuning of parameters using the proposed calibration approach can significantly improve the performance of the simulation model to describe actual traffic conflict risk and operational performances.

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01501394

English

17p

2011

3rd International Conference on Road Safety and Simulation

Digital/other

Figures; References; Tables

Crash data; Microsimulation; Rear end crashes; Risk analysis; Simulation; Traffic safety; Traffic simulation; Vehicle trajectories

Next Generation Simulation program

Surrogate safety measures

Highways; Safety and Human Factors; I80: Accident Studies

TRIS, TRB, ATRI

Jan 29 2014 9:45AM