>In practice? Car ownership is required to participate in society in most parts of the US and governments are very unwilling to take away people's ability to drive.

Because there isn't support for the iron fisted rules enforcement a lot of HN favors and if the .gov just did it anyway the people would elect politicians who promise to reign that in. Keeping the power on the books and rarely using it is what benefits .gov the most so it's what they do.