Simulation models show that collision warning systems with full auto-brake and pedestrian detection features can reduce pedestrian fatalities by 24 percent.

Estimating the impacts of fully deployed collision warning systems using the Volvo Cars Traffic Simulator (VCTS).

Date Posted
04/18/2017
Identifier
2016-B01086
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Benefit Estimation Model for Pedestrian Auto Brake Functionality

Summary Information

Crash data revealed that between 41 percent and 75 percent of crashes involving pedestrians involved passenger cars globally. Of these crashes, 65 percent to 71 percent of the time the pedestrian is struck by the front of the car. In an effort to address this problem, a refined methodology for estimating the potential effectiveness of a technology designed to support car drivers in mitigating or avoiding pedestrian crashes was developed.

METHODOLOGY

Crash scenario data for the benefit prediction method for pedestrian-passenger car crashes comes from the German In-Depth Accident Study (GIDAS). Crashes used in the study occurred between 1999 and 2007 and were limited to pedestrians struck by the front of a vehicle. Additional variables included pedestrian velocity, vehicle speed at impact, speed prior to driver action, driver initiated acceleration (brake) level, maximum acceleration level given road conditions, pedestrian-car first impact in lateral direction, lateral distance from car to object, and obscured sight.

These actual crashes were reconstructed using the Volvo Cars Traffic Simulator (VCTS) and the effectiveness of the reconstruction was based on the accuracy of comparing the predicted injury outcome with the actual injury outcome. Then the reconstructed crashes were tested again with Emergency Brake Assist (EBA) activated to establish a speed reduction baseline, and then with EBA and Collision Warning with Full Auto-Brake and Pedestrian Detection (CWAB-PD) to evaluate benefits versus the baseline.

FINDINGS

With full deployment, the study estimated that the CWAB-PD system can reduce pedestrian fatalities by 24 percent in crashes where pedestrians are struck by the front of a car. Of the 3,500 pedestrians killed each year in EU14 countries, the authors of the study estimated that the CWAB-PD system can save approximately 400 lives annually assuming the system is adopted by all vehicles in the market.

Other benefits of the CWAB-PD system recorded in this study include:

  • Reduced impact speed in 61 percent of cases
  • Collisions were completely avoided in 30 percent of cases.