The Landscape is Full of Zombie-Proof Barriers
The zombies' lack of coordination, along with the inability to see in the dark (we haven't had any infrared zombies yet, but holy ****! We call dibs on the idea) is going to spell the doom of countless zombies in any area outside of a parking lot. This is a group that doesn't know how to find roads or bridges. They just go wandering off aimlessly. Mountains, major rivers and canyons would thus quickly be home to piles of broken zombie rags stinking up the scenic views. Even if zombies had the foresight to not walk over cliffs or into raging rapids during the day, nightfall would result in most eventually walking into rivers, over cliffs and off of bridges, diminishing their numbers.
But even in nice, flat, paved cities, where it would seem like people would be extra-****ed, the landscape still works in favor of the living. History has shown that in most awful situations, people don't always act like the panicky idiots in a horror movie. In cities, people would likely congregate in the upper levels of high-rise buildings, where the invasion can be held at bay with simple security doors. Also, the streets themselves would keep the undead corralled in straight, easy-to-aim-down lines where they could be picked off by snipers, or just bored office-workers waiting out the quarantine by dropping office supplies onto the undead from the top floors.
"Do you think we can fit chairs through this?"