You are driving on a congested section of a major highway. The speed limit is 100km/h, and although traffic is heavy, everyone seems to be driving near the speed limit, although the distance between cars is limted. You know that you are probably not the recommended two seconds away from the small car in front of you, but your SUV has brand new brakes and you are confident that if traffic started braking up ahead, the trickle-down would happen slowly enough to give you and everyone else time to reduce your speed. What you do not anticipate is that the car directly ahead of you will need to make an emergency stop when a large van suddenly makes a dangerous lane change and cuts off the car in front of you. The small car slams on its brakes and you also brake a split-second later, but there is not enough time to avoid a collision. Your SUV rear ends the small car, causing major damage to both vehicles.
Rear-end collisions are an all-too common occurrence on Canada’s roadways. Forward Collision Warning (FCW) systems are a modern, highly sophisticated safety feature designed to help maintain safe distances between vehicles, as well as to prevent and reduce rear-end crashes and accompanying injuries.
Farmer, C. (2008). Crash Avoidance Potential of Five Vehicle Technologies. Insurance Institute for Highway Safety (IIHS). Arlington, VA.
Insurance Institute for Highway Safety. (2012). Crash avoidance features reduce crashes, insurance claim study shows; autonomous braking and adaptive headlights yield biggest benefits. News Release: July 3rd, 2012.
Ontario Road Safety Annual Report (ORSAR) (2012). Annual Report 2012. Toronto, ON: Road Safety Research Office, Safety Policy & Education Branch, Ministry of Transportation.
1 “Doppler Shift” refers to the change in frequency of a wave due to the Doppler Effect. When a vehicle emitting a radio wave is travelling forward, the frequency of the wave is higher due to the forward- motion of the vehicle. Conversely, when a vehicle is travelling away, the frequency of the wave is lower. The Doppler Effect is audible in the case of sound waves: when a vehicle is travelling towards you, the pitch of the sound of the engine seems to be going up. When a vehicle passes you and continues to travel away, the sound of the engine seems to be getting lower.
2An “angle crash” refers to any collision that occurs when one or all vehicles involved is/are hit at an angle; this excludes head-on crashes and rear-end crashes.