Nascar
mass_biker said:
I-15 is something like a zillion lanes wide at this point and cars hurtle by you at Mach 2. You're praying that people pay attention.
I've driven that road to Vegas. Even driving a Suburban at the time, I felt like I was in a NASCAR race. Left lane is 85 mph (no exaggeration), and right lane is 50. Nothing in between. So, you either tailgate (er, "draft") in the left lane at 85, or every moron from L.A. going to Vegas will take the slightest opportunity to pass you on the right and shove their way in front of you. What does this have to do with being on a bike? Well, sometimes, more like frequently, people also pass on the shoulder or force others over onto the shoulder at 85 mph. Not good.
Also, in this area of the country, and I've ridden through it quite a few times, it's usually hot, dry, windy, dusty, but also with very long stretches between services, and hills can be literally 20 miles long with several thousand feet of continuous climbing. Winds can be "normal" at 40 mph.
Check out Google satellite images on alternatives, but definitely do not ride the freeway itself.