Just returned from very enjoyable road trip with my 21 year old son from Cincinnati to San Diego using I-70.
I-70 is a great road but gets a bit tedious going across the wide state of Kansas. Beautiful scenery in the plains though. Even saw a heard of buffalo (or bison?)
Ended up driving 1000 miles on day one due to the sunshine factor. It seemed like the longest day driving west and gaining two hours. We stopped overnight just past the Colorado border. Day 2 drove 900 miles to Las Vegas (had special summer promo room rates on Fremont Street)
The mountains west of Denver on I-70 were interesting. More than I've experienced in the Smokies. Our Honda Civic with a 4 cylinder engine struggled in the highest elevations near the Eisenhower tunnel and slowed down to 60 MPH at times with full gas pedal. Going downhill was no problem except it is one fast wild ride. Tried to be kind to the brakes and was afraid to downshift driving so fast. (and I was in the slow lane.)
I-70 through eastern Utah is like driving through the Grand Canyon with breathtaking scenery. Keep your gas tank full out there, since they are few and far between. One sign said "gas ahead." As I came closer to the exit I saw an arrow pointing north which said "Gas 25 Miles." The 75MPH speed limits in CO, UT and NV are great for making time though.
Deserts were extremely hot, but not really that uncomfortable in the shade. There must be something to the "dry heat" theory. Reaching San Diego after the barren desert was like coming into an oasis. Cool ocean breezes and magnificent beaches. Only downside is car traffic and the cost of gas, ($3.19 - $3.45 I found)
It was a ton of fun and I'd do it again. JoeT