As far as scenery is concerned, I-10 by far.
Interstate 40, Interstate 25, and Interstate 10
* Interstate 10 * Interstate 17 * Interstate 40
Interstate 10.
The best route to drive from Phoenix to Salt Lake City is to take Interstate 17 North to Interstate 40 East, then merge onto Interstate 15 North. This route is approximately 700 miles and takes about 10-11 hours to drive, depending on traffic and weather conditions.
There are three Interstate Highways- I-40, I-10 and I-25.
Interstate 40
3 hours
The best way to travel from Nashville Tennessee to Knoxville Tennessee is by Interstate 40.
US Interstate Highways 10, 25 and 40.
You could be traveling on Interstate 10, Interstate 40, or Interstate 80. These are major east-west highways in the United States.
Interstate 85 isn't really on the way from Murfreesboro, TN to Cardiff, CA. But if you take I-24, I-40 and I-15, the total distance will be around 2,100 miles, and it should take about 33 hours (or more or less, depending on how fast you drive).
Interstate 40, Interstate 75, Interstate 65, Interstate 81, Interstate 55...