Most travel is on foot, by bicycle, on horseback or by boat. A horse costs 60 Credits. A good bicycle is worth a lot, because it is quiet and needs no fuel.
Gasoline went bad years ago. The only fuel is home-made biodiesel or alcohol, and it is rare. A few strongholds keep old trucks and some electric vehicles for important jobs. An engine is a Loud noise, so it brings zombies in a dead city.
The old highways still run between the cities, but they are cracked, overgrown and full of rusted cars. Since the 2050s, the roads between strongholds have been open again. Travelers still face three dangers on the road.
Hordes. Big hordes drift along the old highways and rivers with the seasons.
Raiders. Gangs rob travelers on lonely roads.
Tollmen. Road gangs hold the bridges and truck stops on Interstate 80 across Wyoming and Nebraska. They charge a toll to pass. Sometimes the toll buys real protection. Often it is robbery.
Zombies cannot swim. They sink and walk along the bottom. That makes the open sea the safest place on Earth. The Salt Fleet runs the only regular ships between the continents, from Reykjavik and Honolulu. Passage costs a lot, and captains blood test every passenger.
Almost nothing flies. Continuity Command still has a few working helicopters. A seat on one is a favor, never something for sale.
Winter is the best season for going into a dead city. Below freezing, zombies are slow, and in hard frost they freeze solid. Deserts hold few zombies, because the hot dry air dries them out. Summer is the worst time on the Great Plains, because the big hordes move across them.
Some nuclear plants melted down after the grid failed. The land around them is a Hot Zone. There are no people, few animals and no zombies. The radiation makes people sick. Travelers go around them.
Travel by day. Zombies see worst at night, but so do you.
Stay off the main highways when you can. Hordes follow them.
Cross rivers on bridges or by boat, and watch the far bank. Zombies walk out of rivers.
Always know where the next wall is.
Carry a Blood Test Kit. Test anyone who joins your group.