Well, actually that road is in the mountains not the desert.
"Not much traffic" is a relative thing. Sure it's nothing like shytholes like LA, but there's always a regular flow of traffic on that road. Indianola only has about 50 people, but there are three or four rec property developements right near there. And Hwy 89 is the main route in that area. I'd say a vehicle passes along every few minutes. Sunday can be the worst day. On Sundays when the weather is nice and all the sightseers, campers and fair weather motorcyclists are out it's a regular freeway.