 Make sure your case is solid from day one. Exactly. 866-90-RED-EYE. Brought to you by Hot Shot Secret. Hi, I'm Jen Loomis, a transport safety expert at J.J. Keller, and I'm here to share a tip on speed and space management. In order to manage speed, you need to understand the four factors involved in stopping a vehicle. Perception distance is the distance a vehicle travels from the time you see a hazard until your brain recognizes it.