Before you think this is a Biden issue, funding from the federal government has been given to states with broad flexibility on how to use it and state authorities, by and large, have chosen to persist with car-centric infrastructure. The Biden administration’s department of transportation did advise to prioritize road repair, rather than expansion. States like Texas and California have chosen not to follow this guidance.
How is it not a Biden issue ? Surely it is if you're not setting more stringent guidelines and just throwing buckets of money out. You could have stated no new roads can be built, hell I'd argue the stipulation should have been no money for roads ... at all. Build a light rial line or a heavy rail lone or a new subway station, build some bike lanes etc.
States should know what they need most. If your suggestion is to micromanage the entire road situation for all counties in every state then nothing would get done. Not all solutions are solved with throwing money at it but this is not a place where "build a light rail line or heavy rail" even makes sense. The US already has the most amount of rail of any country on earth. Your suggestion of 'get a new rail bro' doesn't make sense and will likely only be useful for a handful of people whereas fixing the existing infrastructure makes more of an impactful change.
But people don't use buses, mostly because they are slower than driving, and too expensive. Free buses would save money in the long run because you wouldn't spend as much on roads.
So buses are not treated as a serious solutions transit (except for few places with dedicated bus lanes) , and neither are trains.
Unless they have their own dedicated lanes then they are not a viable alternative to driving. If they were converting existing lanes into bus lanes than that would be an affordable and reasonably effective option.
Not those roads, highways. Highways are designed to enter, stay on the highway without stopping except to wait in a traffic jam, then leave. This is terrible for buses which need to stop in-between.
Ideally they would take the opportunity while building the highway to build a parallel busway, but that tends not to happen