Mayor Muriel E. Bowser's budget includes funds for a new limited-stop route.
Supporters of the change say the mandate has discouraged the state from improving service.
Metro said none of the 10 passengers were injured, and the nine bullets didn't breach the passenger compartment.
Two Montgomery County lawmakers have inserted language in the Maryland budget that would require top-level talks among the two states, the District and the federal government on restructuring the transit agency.
A D.C. Council proposal would exempt District residents from paying late fees for failing to pay parking or traffic tickets on time.
Still, some travelers say the policy is outdated and unfairly targets attire worn mostly by women.
Metro is warning of delays up to 35 minutes.
“Since when does @united police women's clothing?” tweeted a fellow passenger.
All passengers were evacuated safely from the train in an incident that Amtrak called a minor derailment, but service has been temporarily suspended.
An unattended bag that was under investigation has been "deemed safe."