A major issue in the United States is that many cities, their suburbs, and surrounding broader region have little to no public transportation infrastructure.

Everyone has to drive everywhere for everything.

This consumes vast sums of oil, generating vast sums of CO2, also necessitates a constant demand for more roads+urban sprawl to keep pace with roads becoming congested.

Efforts to ameliorate this are very haphazard, in contrast to the roads and other infrastructure public transit planning seems to be left down to the lowest level of planning at the city council/county level.

So one area maybe implements a bit of a BRT, another area maybe has a little lightrail, and a third area has some regional locomotive.

With no coordination or cooperation.

And it may also have to be put to a vote allowing those with vested financial interests in maintaining Oil dependency to fund anti-public transit campaigns via sophisticated libertarian think tanks and fronts.

What these cities, their suburbs, and surrounding regions need is a comprehensive public transportation system compromising:
1) Regional & inter-urban rail connecting rural areas and regional towns/cities to one another and major cities
2) Commuter rail to and through a cities suburbia
3) Where appropriate Metro rail inside a city and urban area
4) Streetcars/lightrail, they're the same thing just new technology, on the road in and around the city center and urban area - in medium to low density cities Streetcars and Commuters working together in tandem are an effective alternative to a Metro, you hop off the commuter train and hop on the Streetcar outside and keep going.
They can also be very useful in regional cities, it might have a network of just 3 to 5 or more routes but as seen in Germany with their Tram-Train systems it can be connected to the mainline railways and provide additional services to other towns in the region in between the scheduled Regional and inter-urban trains