There are several barriers that prevent bike riding from becoming more popular in the US. Perhaps the largest is real and perceived safety. Minneapolis used some relatively small amounts of funding to a create a separate paths for bikes using an old path system dating back to the Depression. It isn't perfect by any means, but is a very different approach.
Beyond the bicycle, but not quite up to what people would consider a real car. Small vehicles powered by the driver or a very small engine - an interesting piece on examples from the Mochets. They filled an untapped market - one that has been long since replaced by reliable enough used cars.
Modern examples of velomobiles exist in small numbers in the Netherlands and Germany. They tend to be hand made and expensive.
A big caveat - local numbers can be very different - regions in Idaho and Washington state are much better than the NWPP average while regions in Utah are worse. The estimates do include upstream emissions (well to pump) for gasoline, but those figures will have to change to reflect the increasing use of Canadian tar sands.