I seem to remember years ago that Conrail publicly stated that they did not want intermodal business that originated and terminated on their lines. They only wanted intermodal traffic that they could hand off to western roads at Chicago and St. Louis.

Years ago SP tried running a Sprinter train from City of Industry (Marne) to Phoenix. You would think that would be an ideal market, but apparently the relatively short haul didn't allow the numbers to crunch to a point where they could make a buck.

Canadian Pacific also got burned with their "Iron Highway" concept between Toronto and Montreal, even with reduced labor costs with St. Lawrence and Atlantic handing out smaller paychecks to the T&E crews.

I imagine the same problem would afflict UP if it tried to offer a similar service from L.A. to Las Vegas. It's a nice fantasy --- taking all those trucks off of I-10 and I-15, but the railroads just can't seem to make any money at such an effort.