what are the two main reasons it took the Walls family a month to cross the country from Arizona to West Virginia?

The car breaks down regularly and its top speed is a mere twenty miles per hour.

It took the family so long to travel from Arizona to West Virginia, because it was their biggest skedaddle of the story, and they had to do it in a old run down car the mother bought off the radio.

One reason is that their car,the Oldsmobile, was starting to break down a lot near the New Mexico border and again in Oklahoma. The other reason it took a month to get to Welch,West Virginia is that they had to take scenic detours so they don't tire the car out.