Couldn't leave LA?

The two guys drive for 2 days and they are still somehow in L.A. Even at 10 mph they could have gone to Las Vegas in less time.

The film made it clear only L.A. County was effected. It's not like it would be impossible to portray some people choosing to stay, it still could have been a crisis, but not having them physically able to leave L.A. even with a car is just ridiculous.

The whole time I kept thinking, IF YOU'RE SO THIRSTY, DRIVE ONE COUNTY OVER IT'S FINE THERE. IT'LL TAKE YOU 20 MINUTES. They could have driven to Mexico in 2 hours, or to Oregon in 12 hours. They could have been in Texas in less than 2 days.