The impact of higher or lower weight and volume of cars on road safety, particularly for vulnerable users Richard Cuerden TRL (Transport Research Laboratory, UK) 16/02/2016Presentation for the Committee on Transport and Tourism1

Aim & Research Questions Provide an in-depth analysis of the technological changes necessary to improve the impact of higher or lower weight and volume of cars on road safety, particularly for VRUs 1.Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? (VRUs = Pedestrians and cyclists) 2.Are there disadvantages to being in a small (light) car in accidents compared with a bigger (heavier) car, e.g. SUV?

Background – Road fatalities in EU EU road casualty target approx. 15,000 deaths

Background – Road fatalities in EU28 by user type The downward casualty trend is mainly associated with cars Progress for VRUs (pedestrians, motorcyclists and cyclists) is not as good

Background – Societal trends & future road casualties Likely future societal trends include:  An ageing population  Increase in the number of pedestrians and cyclists  Size/weight diversity in vehicle fleet is going to increase: more MPVs and SUVs and smaller city cars  More driver assistance technologies and vehicle automation Without countermeasures these trends could lead to:  A greater number of road collisions between cars and VRUs (pedestrians and cyclists) because of the increased exposure and a higher likelihood of an impact with an MPV or SUV.  A greater number of road collisions between large and small cars, again, because of the increased exposure and a higher likelihood of an older (more vulnerable) person being involved.

Background – Current type approval requirements  Pedestrian protection (UN R127)  Mainly secondary safety only  Forward field of vision (UN R125)  Has obscuration of short object requirements for SUVs  Crashworthiness e.g. frontal (UN R94) and side impact (UN R95)  Self-protection only

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics

Head-form to bonnet Upper Leg-form to bonnet leading edge Leg-form to bumper Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics Pedestrian protection (UN R127)

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics The red line represents an average MPV profile and shows that different vehicle geometry results in different pedestrian impact kinematics and injury mechanisms

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics The navy blue line represents an average SUV profile and shows that different vehicle geometry results in different pedestrian impact kinematics and injury mechanisms

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics Pedestrian protection (UN R127): Head-form to bonnet region only

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Pedestrian impact kinematics Pedestrian protection (UN R127): Head-form to bonnet region only

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Cookson, Cuerden, Richards, Manning (TRL), IRCOBI 2009  34 British police pedestrian fatal files were analysed, where:  Pedestrian collision with a car registered in 2000 or later  Post mortems were available  Good quality photographs were available showing the damage to the vehicle  The post mortems were coded using the Abbreviated Injury Scale (AIS)  AIS 2+ injuries (serious +) were attributed to the part of the vehicle or ground (object) most likely to have caused the injury

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Cookson, Cuerden, Richards, Manning (TRL), IRCOBI 2009  No AIS 2+ head injuries were correlated with impacts to the UN R127 bonnet test area  27 of the 34 pedestrians sustained an AIS 2+ head injury due to contact with the car  Windscreen impacts caused AIS 2+ head injuries for 12 of the pedestrians  A-pillars impacts caused AIS 2+ head injuries for 8 of the pedestrians  The AIS 2+ head injury caused by the leading bonnet edge was a 7 year old child in an impact with a SUV Windscreen Bonnet

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Summary  Compared to cars, the geometry and shape of SUVs and MPVs is different, which directly relates to the pedestrian injury mechanisms  Higher structures result in less rotation and greater energy transfer, which can lead to increased injury, in particular to the femur and pelvis  Shorter bonnet lengths result in more head to windscreen and A-pillar impacts  Pedal cyclists experience different impact kinematics, their heads tending to hit further rearward  The windshield and surrounding area is not regulated  Pedestrian injury patterns differ with age: -More hip and thigh, less head

Are SUVs and MPVs more aggressive than smaller cars in collisions with VRUs? Summary  Risk of injury (fatality) increases greatly with impact speed  US: Risk of fatality or serious injury increased by up to 30% for SUVs (Note: No pedestrian crashworthiness regulation in US)  EU: Insufficient real world data to evaluate whether SUVs and MPVs are more aggressive for VRUs

 The simple answer is “Yes”  Assuming all other things are equal, e.g. seat belts  Broughton and Knowles (2009) report that, for all accident configurations, occupants of SUVs and MPV have lower injury rates than those of cars, in particular smaller cars. Are there disadvantages to being in a small car in accidents compared with a bigger car, e.g. SUV?  In contrast, an analysis of US fatality data by Wenzel and Ross (2008) shows that overall a person has no greater fatality risk driving an average car compared to a much heavier truck based SUV.  However, it also shows greater risks for car occupants in side impacts if struck by a SUV compared to another car – it should be noted that the US fleet and exposure to risk is significantly different to the EU

 Compatibility and car-to-car frontal collisions: -Structural interaction -Force (frontal) matching and deceleration pulse -Compartment strength and stability  Compatibility and car-to-car lateral collisions: -Structural interaction -Mass and stiffness -Protection against head injury  Older people are more likely to be injured when involved in a car collision, because of reduced biomechanical tolerance.  A person aged over 52 is ~ 4 times more likely to receive serious thorax injury than person under 52 (EC THORAX) Are there disadvantages to being in a small car in accidents compared with a bigger car, e.g. SUV?

Recommendations Improve accident data collection and create a real world evidence base  Not possible to fully answer questions in this review  Best road casualty in-depth data practicable should be collected in a harmonised way across the EU Use US NASS-CDS type model Make freely available to help democratise safety and remove commercial barriers to saving lives

Traffic Sign Recognition Recommendations Measures to improve safety of VRUs  Fitment of Advanced Driver Assistance Systems (ADAS)  Pedestrian and cyclist capable Autonomous Emergency Braking (AEB)  Pedestrian AEB systems may share hardware and software with vehicle- to-vehicle AEB  Intelligent Speed Assistance (ISA)  Lane Keeping Assist (LKA)  Reversing cameras LKA AEB

Recommendations Measures to improve safety of VRUs  Review of Pedestrian Safety Regulation (PSR) EC 78/2009 published 2009 (or UN R127) - Specifically monitoring of upper leg-form and adult head to windscreen tests  Improved crashworthiness of vehicle structure -Improved A-pillar and windscreen frame protection -Improved bonnet leading edge design

Measures to improve safety of vehicle occupants  For frontal impacts adaptive restraint systems -Better protection for thorax (especially for older casualties injured in lower severity impacts) as well as in impacts against different sized vehicles  For side impacts curtain airbags -Provide head impact protection for front and rear -Ideally, should also help mitigate occupant ejection (FMVSS 226) and thus help in rollover accidents too Recommendations

Measures to improve safety of vehicle occupants  More stringent crash test legislation for heavy on-road quads -There may be a shift towards a greater number of these vehicles because of the potential for fuel efficiency -Currently, there are fewer safety standards for quadricycles, e.g. frontal and side impact tests and pedestrian protection

General and Pedestrian Safety Regulation Benefit and Feasibility of Potential Measures Recommendations

Thank you Presented by: Richard Cuerden Chief Scientist, TRL