car AI to slow down in turns

Im using Randomation Vehicle Physics for this and they dont come with this feature equipped. If there is a turn how to calculate the speed requiered not to slam in the wall or fully stop? RVP uses "Speed" value 0 to 1 for how fast the car is going, so maybe there is a way to make it so it goes on 1 when its straight road but drops to something like 0.3 when its 90° turn? I like the approach Standard assets has done, but i dont know how to extract it properly.