The dynamic signalization of calamity routes – a driving simulator study

Abstract

Calamities (e.g. accidents) in the vicinity of freeway interchanges can simultaneously block several branches of the interchange for road traffic, resulting in heavy congestion or unsafe driving conditions. Therefore, drivers should be informed in time about these calamities. Digital displays alongside freeways are an excellent medium to warn drivers approaching the interchange and provide some rerouting alternatives. The objective of this study is to investigate the effectiveness of a sequential message strategy (including digital displays) announcing that a calamity has occurred and therefore advise the drivers to reroute. In this study, different types of messages and two types of digital displays (gantry and cantilever) are used to indicate that an accident occurred at the interchange and that one or more branches are blocked. Furthermore, these messages instruct the drivers to take the exit and follow a calamity route (i.e. diversion). After leaving the freeway, the calamity routes are indicated using different letters (e.g. ‘A’) for the possible destinations. Sixteen subjects participated in the simulator study and drove through five scenarios after receiving instructions concerning their destination. The apparatus used consisted of a medium fidelity simulator mock-up equipped with an eye tracking system. Instead of being exposed to a virtual driving environment, participants drove through a real-life full HD video recorded road environment in which 3D virtual traffic signs had been digitally integrated. Participants’ route choice and their visual behavior were monitored while navigating through the scenarios. Results indicate that most of the participants obeyed the instructions on the digital displays and thus made the correct route choice. However, some participants neglected the advice and did not take the appropriate exit. Furthermore, small differences were found between the two types of digital displays. In general, cantilever displays generated longer fixation times than the gantry displays.