What are the laws regarding sleeping in a card and / or camping on the road?

My friends and I are going on a road trip later this year, but we want to save money is not going to hotels along the way (and even limit the number of shelters we visited). Part of the way he can stay in the homes of friends and relatives, but not the whole way. What I wonder is, what are the laws in California, Oregon, Washington and British Columbia in relation with sleeping in a car and / or roadside camping?

Most states in the U.S. do not allow camping in his car beside the road. For motorways interstate (like I-5, which sounds as if you travel) can only be stopped in an emergency, such as car brakes down, run out of gas, accidents, etc. Try camgrounds looking down the road. There are beautiful places to camp not far from I-5 along this route through the Northwest, and the rates are less than a hotel, about $ 20/night

Hawaii Court Rules Against Law Banning Camping At Parks