While driving from South Los Angeles to Washington DC, the bus takes the Pasadena Freeway north from downtown LA. This freeway ends in Pasadena and is not the way one would travel across the country. Furthermore, a bus of this size would not be permitted on this freeway.
By evening on the second day of driving, the bus had gone from Los Angeles, CA to Memphis, TN (almost 1,800 miles). Despite driving through the night, by evening on the third day they had only traveled as far as Knoxville, TN (almost 400 miles).