Umh, with public debt its not so simplistic, at least if you look at the bigger picture. Budget deficits (that also can have rising financing costs further down the road) can hide exploding and unsupported infrastructure costs for decades and then there are local budgets and bankruptcies of municipalities etc and last but not least there is also simply insufficient road infrastructure maintenance because not even debt can stem the weight anymore.

Also, if you don't need those roads but have to pay a lot for them, that is certainly not splitting hairs either. Hard to imagine for some but even in the US there are places were substantial number of citizens don't use cars very much or might not even own one (even though they could afford one). In better developed countries than the US that number can be even very substantial in urban environments.