From the introduction:
Roadworld is based on Blade Runner + Repo Man + Road Warrior + Judge Dredd + other ideas. The setting is the 24th century. The world is on a downhill slide, morally, economically, and environmentally. The cities, which have become sprawling metropolises larger than many of the former states of the United States, have become independent throughout the world.
The outside environment is wild and unruly, inhabited by thugs and irradiated freaks; being cast into the wilderness is virtually a death sentence, except for those who are extremely tough or extremely clever. Fossil fuels are almost nonexistent; flight has been abandoned due to increasing lack of safety and the scarcity of fuel. Massive truck convoys lurch slowly between cities, conserving their fuel by going very slowly (almost running on fumes) and steady. The intercity infrastructure is nearing disintegration and what were once highways are crumbled dirty trails, often blocked by debris - which often serves as a point where the marauding biker thugs living outside the cities can ambush the truck convoys.