Estimate of Potential Benefit for Europe of Fitting Autonomous Emergency Braking (AEB) Systems for Pedestrian Protection to Passenger Cars

Abstract

Objective: The objective of the current study was to estimate the benefit for Europe of fitting precrash braking systems to cars that detect pedestrians and autonomously brake the car to prevent or lower the speed of the impact with the pedestrian.

Methods: The analysis was divided into 2 main parts: (1) Develop and apply methodology to estimate benefit for Great Britain and Germany; (2) scale Great Britain and German results to give an indicative estimate for Europe (EU27). The calculation methodology developed to estimate the benefit was based on 2 main steps:

1. Calculate the change in the impact speed distribution curve for pedestrian casualties hit by the fronts of cars assuming pedestrian autonomous emergency braking (AEB) system fitment.

2. From this, calculate the change in the number of fatally, seriously, and slightly injured casualties by using the relationship between risk of injury and the casualty impact speed distribution to sum the resulting risks for each individual casualty.

The methodology was applied to Great Britain and German data for 3 types of pedestrian AEB systems representative of (1) currently available systems; (2) future systems with improved performance, which are expected to be available in the next 2–3 years; and (3) reference limit system, which has the best performance currently thought to be technically feasible.

Results: Nominal benefits estimated for Great Britain ranged from £119 million to £385 million annually and for Germany from €63 million to €216 million annually depending on the type of AEB system assumed fitted. Sensitivity calculations showed that the benefit estimated could vary from about half to twice the nominal estimate, depending on factors such as whether or not the system would function at night and the road friction assumed. Based on scaling of estimates made for Great Britain and Germany, the nominal benefit of implementing pedestrian AEB systems on all cars in Europe was estimated to range from about €1 billion per year for current generation AEB systems to about €3.5 billion for a reference limit system (i.e., best performance thought technically feasible at present). Dividing these values by the number of new passenger cars registered in Europe per year gives an indication that the cost of a system per car should be less than ∼€80 to ∼€280 for it to be cost effective.

Conclusions: The potential benefit of fitting AEB systems to cars in Europe for pedestrian protection has been estimated and the results interpreted to indicate the upper limit of cost for a system to allow it to be cost effective.

Keywords:

• pedestrian
• benefit
• active safety
• crash avoidance
• brake assist
• AEB

Additional information

Funding

The authors gratefully acknowledge the support of the European Commission and the German Federal Ministry of Transport, Building and Urban Development and thank other ASPECSS project partners for their input into this work. They also acknowledge the UK Department for Transport for permitting the use of the OTS (On The Spot) accident study. The OTS data forms part of the Road Accident In Depth Studies database; further information can be found at https://www.gov.uk/government/publications/road-acci-dent-investigation-road-accident-in-depth-studies.