A bigger problem might be the geographic distribution of truck vs. rail traffic. Rail traffic dominates in the transcontinental trips, because it's a lot cheaper to ship bulk cargo or shipping containers by rail from LA to Chicago, than by truck. But open-road inter-city trucking from LA to Chicago is relatively safe. Where trucks are most dangerous is within-urban-area transit, in congested metropolitan areas, but those are also the hardest to replace. For example, Safeway alone sends thousands of trucks out daily to supply its grocery stores; much of the produce is moved from ships to a local staging area by rail, but the last 10 miles to the actual store goes by truck. It'll be very difficult to replace that, unless we return to the days of a dense rail network where businesses had their own local rail sidings for deliveries.
Rail is a great solution for a specific portion of that network, but it becomes very, very inefficient if you're only moving one box of goods to a town, and in a nation this size, with as dispersed a population as ours, you simply cannot manage the outlay of hundreds of thousands of railway spikes...and taken to the smaller position, you'd still need trucks unless the railways went to each and every department store.