Is there any particular reason why people would want to stop at Primm instead of somewhere else? This only needs to be a top-off stop of 5-15 minutes, so why is access to more than a bathroom and a cold drink needed? Are people really that desperate to play slot machines as early/late as possible? ISTM that putting the SC at Stateline Service (65845 Cima Road, Nipton, CA.) provides better spacing, especially considering where the major climbs are. Stateline is 90 miles from Barstow and 65 from Las Vegas, while Primm is only 43 miles from Vegas and before the major climb, so you won't be able to charge very fast coming back in any case. Looking at the profile on gps visualizer, Stateline is in the middle of major climbs from both sides, and looks a lot easier for 60s to reach from Barstow than Primm. Granted, the location isn't upscale, but for such a short stop, who cares?