We're driving from Seattle to visit friends in Tucson. We would like suggestions for the fastest/easiest/most direct driving route south.

We will take our time when we return northward and will use the many scenic route suggestions already suggested on this forum.

I-5 south to Bakersfield, east on 40 through Barstow, Needles, Kingman, south at Flagstaff on 17, east from Phoenix on 10. Note that Bakersfield isn't right on 5, you have to cut over on a local road.

That route took about 3.5 days when we moved down here, but we dinked around in Sacramento and Sedona for a bit. You could probably do it in a couple of really long days if you were so inclined.

Google Maps says I-5 to I-210 to I-10 to Tucson is the shortest way (160 miles shorter than taking I-40 via Flagstaff). I did most of it the opposite way Phoenix to Portland a couple of years ago. It all worked out fine as I remember.

A friend just mentioned a 3rd route, but as it's not mainly by interstate, don't know how quick it would be. Maybe less congestion?

Has anyone travelled Seattle to Twin Falls Idaho via I-90, and I-84, then south on Highway 93?

Google maps shows the Twin Falls route you mention as being an hour longer but 87 miles shorter (1531 miles vs 1618 miles) than taking I-5 and I-10. It may well be quicker too, because in my experience Google Maps isn't all that accurate in calculating long-term travel times.

So I'd consider the Twin Falls route for sure, although I've not driven 93 so I don't know how congested it gets. I'd ask someone who has driven both routes.