The largest sources of transportation greenhouse gas emissions in 2021 were light-duty trucks, which include sport utility vehicles, pickup trucks, and minivans (37%); medium- and heavy-duty trucks (23%); passenger cars (21%); commercial aircraft (7%); other aircraft (2%); pipelines (4%); ships and boats (3%); and rail (2%).
Driving accounts for a larger percentage of emissions than you’d think - something like 14% of emissions are gasoline alone.
Electric cars have about half the lifecycle emissions of gas cars, so that’s equivalent to a ~7% reduction in emissions - more if the grid goes solar.
That said, replacing suburban sprawl with traditional denser streetcar suburbs like you see in the Netherlands would be a much bigger reduction in emissions.