Some of the jobs that I do for a living include driving a semi-truck. Years before I ever heard of hammock camping I thought that a hammock in the truck would provide a much better sleep then the 'bunk' in the truck.
Here is my idea: Using 2" webbing, weave the strapping over and under each strap (think of basket-weaving, or lawn chairs). This should be strong to (a) support 10x body weight in the event of a crash, and (b) be comfy enough to sleep in while the truck is bouncing down the road.
This is the strapping I imagine i would use: http://www.strapworks.com/High_Tenac...ene_p/htp2.htm
Ships have used hammocks for crew sleeping for CENTURIES, the sway of the hammock could counter the motion of the ocean, and gently rock the sleeper to dreamland. I think that the same principal would work in a truck. Annoying bumps and jiggles on the road would be dampened allowing for better sleep.
In the event of an accident the hammock would be the safest location in the truck because as the truck stops suddenly, all of the body-weight would be directed towards the back of the sleeper (like in a childs safety car-seat), and the hammock would swing towards the front of the truck keeping the sleeper from falling out.
1) This whole concept is dependant on adequate supports and bracing the 'Sleeper' area of the truck. For this exercise lets assume it exists.
2) A 100km/h -> 0km/h deceleration at 0.2seconds = 14G's of force. I used this measurement to determine that +10x body-weight support would suffice.
Thoughts, ideas, discussion.