Influence of pedestrian-to-vehicle technology on drivers' response and safety benefits considering pre-crash conditions

Pedestrian-to-vehicle (P2V) technology may offer a promising approach to reducing pedestrian crashes. However, its influences on both driver response and safety benefits have been little studied in previous research, particularly in regard to the variation of influences between different pre-crash scenarios. To investigate these influences, this study designed three pre-crash scenarios based on pedestrian crash contributing factors identified from crash reports, and collected 44 drivers' driving simulator experiments' data. The results clarified how using P2V technology to warn drivers of an impending collision improves safety by causing a series of changes for both brake operation and braking profile. These series of changes were further demonstrated to vary between scenarios. The study showed that P2V technology may be particularly useful in scenarios in which a pedestrian's crossing intention is unclear; specifically, in this type of scenario, the P2V warning had changed the braking process from a panic brake of "slow reaction-hard brake" to a comfortable brake of "quick reaction-gentle brake." In addition, the P2V warning may be less effective in "low-risk" level scenarios where a driver is confident that he/she can handle the situation through a more conservative evasive action and don't need to react strongly to a warning. Moreover, depending on the pre-crash scenario, the P2V warning may be mostly beneficial for drivers who had a crash/citation in the past five years and working-aged drivers. (C) 2020 Elsevier Ltd. All rights reserved.