The transit riders for public transportation sponsored the rally outside of Oakland City Hall.
Members of the group want Congress to give local transit agencies greater flexibility on how they spend the money they receive from Washington.
A change in the law would allow money earmarked for capital improvement projects would instead pay for operating existing buses and trains.
"These transit services are vital in getting families to work. These services are necessary to get students to school. These services are important in helping families shop and play," said Contra Costa County Supervisor John Gioia.
The bill is co-sponsored by two Bay Area lawmakers East Bay Democrats Barbara Lee and Jerry McNerney.