My folks drug us kids back and forth from Missouri to California multiple times a year and then when I had a family I did the same. It would not be an overstatement to say I have been over 66 and now 40 dozens of times. Never been on I10 but like I think it was Crusher who mentioned it is too close to the border for comfort. Arizona has some decent mountains around Flagstaff but not real steep NM is typical interstate nothing out of the ordinary but yes get gas in Kingman, AZ your wallet will thank you. Also try to hit Needles early AM if possible I have been there in 118 degree heat I would suspect Sept will still be hot. The Hwy now bypasses Mohave so that helps make it a better shot but I do miss gawking at the planes. Once you hit Barstow you are home free now that they cleaned up that maze of roads trying to get on 58 from I40, Tehachapi mountains are not that steep westbound mostly downhill into Bakersfield then 99 takes you home. Pretty clean drive, there are even some cool tourist traps to stop at if you are so inclined to take a break. I think I could do it in my sleep and probably have! I remember back in '86 I left Springfield, Mo Friday evening headed back out to Calif and made it to just outside Kingman and could not stay awake any longer so I pulled of in a large gravel area along I40 and stretched out in the seat to catch a few zz's and when I woke up 2-3 hours later there were 10-12 tractors with trailers parked all around me idling and I never heard a one come in, lol.
