Europe has a similar population and area. The use of public transit is much better over there than in the U.S.
The Chinese rural population is also sparsely dispersed. Yet people are able to put together public transit and use them effectively. Why can't the US.
I see little vans carrying people around in rural China. The US should have the same but chooses not to allow them. In New Jersey, some Hispanics have been running illegal van networks for years in the Jersey City/Hoboken area and were never able to have them legalized. The reason was high entry barriers of the public transit space consisting of legal and insurance requirements.
based on the above, I don't see the US trying as hard as it could to push public transit. The rusting rails in the vast Midwest reinforce my impression.
The roads in the US have no usable bike lanes. I say usable because some roads do have narrow lanes marked for bikes, but they are not physically separated from the car lanes and thus extremely dangerous. One easy thing the government can do is physically separate the bike lanes to encourage bike usage.