From toilet plungers for bike lanes to community gardens on vacant lots to locally sourced incremental development, citizens are finding creative ways to make urban space while bypassing traditional bureaucratic systems.
(You can do an impromptu protest by yourself, too: when a car stopped in the bike lane blocks your path, simply pull up next to it and block the general-purpose lane while you wait for the obstruction to clear.)
There are plenty of things you can do as a cyclist to force change.
What is a just a minute protest? asking for a friend
https://www.youtube.com/watch?v=kDboYpYvT2o
(You can do an impromptu protest by yourself, too: when a car stopped in the bike lane blocks your path, simply pull up next to it and block the general-purpose lane while you wait for the obstruction to clear.)
Many cities have community cycling/active transportation coalitions which advocate for bike lanes and other active transport infrastructure.