I can think of lots of political roadblocks to higher levels of spending on transportation infrastructure, but the idea that voters don't care about it seems implausible to me. And yet here I read "Silver Line to Dulles not important to most Virginians, Post poll finds". In response, Alec MacGillis emphasizes the point that Virginia is a medium-sized and somewhat funny-shaped state, so naturally people who live nowhere near the Silver Line route aren't especially interested in the topic. The very same poll reveals that voters in the suburbs of Washington DC care a great deal about a signature local infrastructure project.
To me that regional divided much better expresses the political roadblock to this sort of investment. From a transportation-planning perspective it makes a lot of sense for people living in Herndon and Alexandria to be co-deciding with people who live in DC and Bethesda and Largo. It makes basically no sense for them to be co-deciding issues with people who live in Norfolk or Roanoake. Even places like Richmond and Charlottesville that aren't outrageously far from the DC suburbs are still substantially further away than even Baltimore. But state governments have a crucial role in infrastructure planning and infrastructure finance, even though the political units they govern often have no correspondence to meaningful economic units.
But the really weird thing is that it's by no means clear that this is what the poll has found. What it says is that 32 percent of the population says the Silver Line project is "not at all important" while 32 percent deems it either "extremely" or "very" important and a further 32 percent says it's "somewhat" important. The "not important to most Virginians" interpretation is supported by lumping the "somewhat" and "not at all" categories together as "negative" responses. But the straightforward reading of the poll is that the median Virginian thinks the Silver Line project is somewhat important. And it is somewhat important! So why not just say that?