How Does the Driver’s Perception Reaction Time Affect the Performances of Crash Surrogate Measures?

Abstract

With the merit on representing traffic conflict through examining the crash mechanism and causality proactively, crash surrogate measures have long been proposed and applied to evaluate the traffic safety. However, the driver’s Perception-Reaction Time (PRT), an important variable in crash mechanism, has not been considered widely into surrogate measures. In this regard, it is important to know how the PRT affects the performances of surrogate indicators. To this end, three widely used surrogate measures are firstly modified by involving the PRT into their crash mechanisms. Then, in order to examine the difference caused by the PRT, a comparative study is carried out on a freeway section of the Pacific Motorway, Australia. This result suggests that the surrogate indicators’ performances in representing rear-end crash risks are improved with the incorporating of the PRT for the investigated section.

A Novel Surrogate Safety Indicator Based on Constant Initial Acceleration and Reaction Time Assumption

“…Kuang et al [4] add the reaction time of the vehicle following the DRAC obtaining the Modified DRAC (MDRAC). This parameter is calculated as follows:…”

“…The DCIA can be determined by substituting (5) and (6) into (4). The required deceleration to avoid an accident is thus calculated according to the following formula:…”

“…Kuang et al [4] argue that the initial determination of DRAC does not consider the PRT of the following vehicle. They modify this specific safety indicator by implementing a factor including PRT.…”

“…Because of this, car interactions are considered to be safe as long as the following vehicle has a lower speed compared to the leader although the two vehicles might have high speeds and small gaps between each other [3]. Moreover, the reaction time of the road users is often neglected [4].…”

Analysis of risk levels for traffic on a multi-lane highway

“…See e.g. Minderhoud and Bovy (2001); Kuang et al (2015bKuang et al ( , 2017; Wang et al (2017) Among these we recall the Headway Distribution, the Time-To-Collision or the Aggregated Crash Index.…”