As the subject of DC-295 is still part of the discussion here, I recently read an article on ggwash about some of the history of the corridor.
As a warning, a lot of ggwash stuff is very pro-transit, pro-bike, and anti-car.
The first article in the series definitely reads a bit like an anti-freeway screed:
How DC Route 295 isolates neighborhoods in Northeast DC from the rest of the city
As to be expected, much emphasis on air quality impact of the traffic - but no mention of the air quality impact of greatly improved vehicle emission controls and reformulated fuels. Nor any mention of the air quality impact of the decommissioning of the Benning Road coal-fired generating station, which was torn down several years ago.
The second article, though, is defintely worth reading and has a lot of interesting history and map links:
Here’s how neighborhoods west of Kenilworth Avenue in Northeast DC became isolated from the city
This one is indeed better.
One thing that the author seems to not be aware of - streetcar service in the Benning Road corridor (I think those were Routes 10 and 12) were decommissioned and replaced with bus service for one simple reason -
the streetcars could not serve the demand and buses could.
One big reason why was the "plow pit" on H Street, N.E, where inbound streetcars stopped to have the trolley pole lowered and the "plow" attached to rear truck of the car (power was DC, with the power rail in the conduit having a positive and negative pole (one side of the plow was for positive and one side was negative)).
There was a dedicated employee at each plow pit at all times when trolley service was running This job required going under the car to the pit to attach (inbound) or remove (outbound) the plow and then lowering the pole (inbound) or raising it (outbound). This was a miserable job, exposed to the elements and sometimes dangerous involving exposure to live traffic and enough electric power to be lethal.
Outbound cars had the plow removed and the pole raised.
The conduit system existed because Congress had forbidden overhead wires in the monumental core of D.C., including trolley wires.
The National Capital Trolley Museum on Bonifant Road in Silver Spring (overlooking MD-200) has at least one example of a plow in their collection open to the public - these things were heavy beasts.