They didn't have Samuel or Aldo with them, who had to repair and set up something with the communication towers, so they didn't have to consider it in their plans.
They only chose routes that wouldn't go through too populated areas of humans and animals because of zombies and also mutant animals. They also didn't choose those areas where they had to cross a lot of forest because of possible attacks from a lot of conscious plants.
Because of those considerations, it took an hour for them to finalize their routes.
Of course, they had plotted their route according to the circumstances that they remembered and knew about the situation in the south, so they're also not sure of the route that they had planned.
But Luciel didn't care as long as they had plotted the general route that they'll have to use.
