The first D.C. streetcars, like this one being tested near Union Station, will operate on H Street and Benning Road NE. (Robert Thomson/The Washington Post)

You still can’t board a streetcar in the District, but as of Monday you can get a ticket for blocking the path of one.

The District Department of Public Works will begin ticketing and sometimes towing vehicles along H Street and Benning Road NE that are parked in a way that impedes the path of the streetcars, which will be running along the route in a continuation of their testing phase.

Enforcement of the parking rules — consistent enforcement — will be a key to successful streetcar operations. Unlike buses, the streetcars can’t veer around parked cars to get into another lane. Without tough enforcement, it will be easy to throw the District’s first modern streetcar operation off schedule.

It’s still just a test, because the District has yet to announce a start date for the long-delayed service. The car barn, which will serve as a maintenance facility, is still under construction.

The fine for blocking the path of the streetcar is $100. Tickets issued up to this point have just been warnings. A driver could get the ticket for double parking in such as way as to overlap with the streetcar route, or parking outside the white lines that mark the borders of legal spaces. A ticketed vehicle could also be towed a nearby street, out of harm’s way.

The definition of “blocking the path” is a bit broader than just parking on top of the tracks. It includes sitting your vehicle on any part of the area where streetcars operate, including the concrete slab in which the tracks are embedded.