I had 'stealth camped' on a two week (riding time) trip across the Midwest back in the '70s. I didn't pitch a tent or hammock, preferring to sleep on the ground. My only protection was a plastic garbage bag and a plastic sheet that I'd cover myself with to keep the dew off. If I was lucky, I'd find a piece of cardboard or carpet for a pad to lay on, and I used my duffle bag with spare clothes as my pillow. I tried to find myself a bridge, overpass or culvert to sleep under in case it rained during the night. Only once did I sleep at a roadside rest area -- under a picnic table.
I let the road traffic be my alarm clock - usually at the beginning of the morning rush. I'd ride for 80-100 miles, stopping for eats at roadside fruit and vegetable stands (gotta love riding in the rural Midwest in August!) By 5pm or so, I'd stop riding for the day and started looking for a good place to spend the night, even though I still had plenty of daylight. I wanted to find an out-of-the-way quiet place, and look around for something to sleep on, etc, grab 'the special' at a local diner, a couple of burgers at McDs or other, then wander aimlessly until dark when I'd return to my chosen spot.