[Someone1234]

I'd argue that's a design problem.

A lot of cities have built street cars in the middle of the road, or they place concrete edge between parking and the street car's lane to stop exactly that from happening. Why didn't DC?

This seems incredibly dangerous and poorly thought out:

http://i.imgur.com/WbWrf9l.jpg

I understand that civil engineers are sometimes handcuffed with what they can do. But the city really needs to decide how seriously it is about this project, and either design the city around the streetcars or just eliminate them completely.

It just looks like they tried to half-arse it and it blow up in their face.

Honestly Salt Lake City is a map of where the US needs to go, not DC. Cycling lanes everywhere and streetcars with dedicated space and priority. It isn't perfect (cycling lanes need more protection, like Copenhagen, actual concrete to stop cars driving or parking in them) but it is darn good by the US's standard.

[distances]

I've lived in two European cities with extensive tram lines. Both of them have trams on the streets, but the other one also has dedicated lanes in places where streets are wide enough. The dedicated ones are very fast and enjoyable to ride, but even the on-the-street lines are way better than buses.

Blocking the rails happens very rarely, so I assume it's about everyone getting used to it, plus hefty towing fees.