Complex sentence: Speed bumps of various sizes can be placed on a road, from using two four foot or six foot devices on it with a space on either side for drainage, and not designed for avoiding the bump on one side of the car.
Split into simpler sentences: Speed bumps of various sizes can be placed on a road, with two four foot or six foot devices on it with a space on either side. The space is for drainage, and not designed for avoiding the bump on one side of the car.