Rush hour in Amarillo is really only about fifteen minutes long (and only in the Central Business District). That's not due to an absence of vehicular activity, it's because Amarillo's streets, thoroughfares and expressways are laid out so well that traffic flows smoothly, the result of careful planning. It's simply easier for people here to get around.
You'll find motorists in Amarillo to be very courteous in comparison with those in large cities. The city's streets and freeways are well designed and can accommodate lots of vehicles, so drivers don't have to try to be so aggressive. Even during heavy commute periods, there's nothing to impede you from driving the speed limit.
No matter where you live in Amarillo, you're close to the services and amenities you expect: restaurants, familiar banks, multiplex theaters, drugstores, supermarkets. And if you're short of cash when you stop to pick up your clothes at the cleaners, they'll probably tell you to just pay the next time you come in.
There are no natural obstacles to avert traffic, so Amarillo's streets are mostly perpendicular, making it easy to get around. Major arteries provide easy access through and across the city. Interstate 40 and Interstate 27 each bisect the city just south of downtown, dividing the city into equally sized quadrants. Loop 335 encircles the city, providing another way to easily cross from one side of the city to the other.