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My drivers education course (in the US) emphasized steering to avoid a collision first, and then braking afterwards. We were taught that colliding with a pole

by vlad 17y ago

My drivers education course (in the US) emphasized steering to avoid a collision first, and then braking afterwards. We were taught that colliding with a pole at 35 mph is better than doing so with oncoming traffic for a total effect of 70 mph. It also reduces the chances of injury. After reading that pilots are the safest drivers, I've made sure to always look around my car as I drive.

evgen 17y ago
Ditto. The thing that seemed to trip up most people in the simulators was remembering to correct for the swerve. Most would turn hard right/left to avoid the obstacle and then forget to make a fast counter-turn to avoid running off the road.
daveungerer 17y ago
Remember that F = ma. Hitting another car of the same size coming from the opposite side when each car is doing 35 mph is pretty similar to hitting a concrete wall at 35 mph. There is no 70 mph effect. The reason the pole would be safer is that it has some give. Lower acceleration = lower force.
- daveungerer 17y ago
  If someone could explain why I was voted down, that would be great. Thanks.
  - sailormoon 17y ago
    I didn't vote you down, but you cannot assume the cars are of identical size and mass, or indeed that it's a car at all. Hit a truck at 35, while he is also doing 35, and you'll feel a 70mph effect all right. For a few milliseconds. Unfortunately, poles, especially old ones, do not have as much give as one would like, and large trees have basically none. Plus, their narrow aspect is a very bad thing to hit; cars are designed to collide with large, flat, wide objects and to crumple accordingly to wash off energy. Hitting an immoveable narrow object is outside this design consideration and cars have a nasty tendency to wrap around it.
    - daveungerer 17y ago
      I was just making the point that justifying swerving out due to some undefined 70 mph effect is incorrect if you don't know what you're dealing with. And that whoever came up this 70 vs. 35 mph effect justification should realise that it mostly applies to e.g. the truck example you gave and somewhat to cars of significantly different mass / size. Therefore it's confusing advice and obscures other possible good reasons for swerving out.

by vlad 17y ago

evgen 17y ago

Ditto. The thing that seemed to trip up most people in the simulators was remembering to correct for the swerve. Most would turn hard right/left to avoid the obstacle and then forget to make a fast counter-turn to avoid running off the road.

daveungerer 17y ago

Remember that F = ma. Hitting another car of the same size coming from the opposite side when each car is doing 35 mph is pretty similar to hitting a concrete wall at 35 mph. There is no 70 mph effect. The reason the pole would be safer is that it has some give. Lower acceleration = lower force.

daveungerer 17y ago
If someone could explain why I was voted down, that would be great. Thanks.
- sailormoon 17y ago
  I didn't vote you down, but you cannot assume the cars are of identical size and mass, or indeed that it's a car at all. Hit a truck at 35, while he is also doing 35, and you'll feel a 70mph effect all right. For a few milliseconds. Unfortunately, poles, especially old ones, do not have as much give as one would like, and large trees have basically none. Plus, their narrow aspect is a very bad thing to hit; cars are designed to collide with large, flat, wide objects and to crumple accordingly to wash off energy. Hitting an immoveable narrow object is outside this design consideration and cars have a nasty tendency to wrap around it.
  - daveungerer 17y ago
    I was just making the point that justifying swerving out due to some undefined 70 mph effect is incorrect if you don't know what you're dealing with. And that whoever came up this 70 vs. 35 mph effect justification should realise that it mostly applies to e.g. the truck example you gave and somewhat to cars of significantly different mass / size. Therefore it's confusing advice and obscures other possible good reasons for swerving out.