On roads around the world, how are safe speed limits decided and what factors go into making those decisions?

Question

On roads around the world, how are safe speed limits decided and what factors go into making those decisions?

In: 3

Answer 1

It will vary in different places around the world. Straight, flat roads with little to no risk of foreign objects (ie. gravel/rocks) fouling the surface would get a higher speed limit than a road with lots of tight corners and frequent rock faces dropping rocks and gravel on the road as they erode.

Weather conditions may also determine speed limits, especially in stretches of road that see dramatic changes in altitude. If ice/rain are common, the speed limit will be reduced accordingly.