I do not mean the old route through Promontory, but the causeway across the lake. Personally, I do not think it a good idea and I told my BIL such, but he is thinking about it.

As for the old ROW through Promontory, I did look into it once. I even asked a ranger at the Golden Spike Monument about the conditions. He actually did not recommend it. He said they have a few people who try driving it each year and many come back with multiple flats from spikes. He said one year they might have none, but the next year most would come back with 2 or even 3 flats. Since tires on my truck cost as much as the annual GDP of a small island nation, I have decided not to try it.