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.
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.
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...
The highest elevation along Interstate 10 is near Wilcox, Arizona, where it briefly reaches 5,000 feet.
40/10 = 4 hours