Originally Posted by
evergrn
Are you sure you can't just rent a car at PHX? What would you do without a car once you get down to Tucson? It's a quick drive (75-120min depending on where you're going). From the rental car facility at PHX, you get on I-10 southbound right nearby and it's one-shot drive... although I do admit it's not the most relaxing drive because the speed limit is way too fast (75mph) considering there're only 2 lanes with a lot of slow trucks.
If you're really worried about sleep deprivation, then can you spend a night near PHX before heading down?
The drive has improved somewhat as an additional lane has been added for a good portion of I-10 along the route. Still, as a mostly flat straightaway through largely uninteresting terrain people tend to floor it through here.
The OP would be wise to avoid this drive at night if worried about sleep deprivation. However in the middle of the day I'd say grab a coffee and hit the road unless you suffer from narcolepsy. The drive doesn't take much more than 90 mins and will definitely be your cheapest option for 4 people, plus you will want a car in Tucson if planning to do anything other than lounge at the hotel.