Whether the speed humps actually slow the vehicles down probably depends on the type of vehicle and the owner's respect for his/her vehicle. From my experience, the cars do appear to be traveling slower, but I have no before/after data to support the assertion.
Does it really matter if I drive 30mph in a 25mph zone? The following info appeared in a publication of the Australian Academy of Sciences.
- This math problem revolves around Sam. A typical little kid who doesn't always look both ways before riding his bike into the street.
- On this day, Sam doesn't see the two cars traveling toward him. Car #1 is plodding along at the 24mph just under the speed limit while car #2 is traveling a little faster at 30mph.
- When Sam enters the street, both drivers are paying attention and see Sam at the same time. Sam is about 25 yards up the road.
- If we assume an average reaction time, the driver of car #1 can stop in about 75 feet (55 feet to apply the brakes and another 20 feet to stop the car) just missing lucky, little Sam.
- With a similar reaction time, the driver of car#2 won't leave Sam so lucky. By traveling 6mph faster, the driver will be only 7 feet away from Sam when he first hits the brakes, and at the point of impact, the car will still be traveling 22 mph. Even after hitting Sam the car won't come to a complete stop for another 25 feet.
Add a hump, save a life!