Most of the DC beltway is 4 lanes in each direction, although parts are both wider and narrower. I oppose this plan because I think over 3 lanes in each direction costs more than the marginal increase in capacity is worth. The other problem is than the roads once you get off the beltway cannot handle any increase in traffic, I have seen the off ramps to River, Connecticut, and Georgia Roads back up onto the beltway.
Can you sneak over to Annapolis some day and whisper that into Gov. Hogan's ear? Adding lanes is just going to create a wider parking lot in rush hour. That said, if Maryland has money to burn and Maryland pols want to pander to frustrated commuters, so be it. Since I don't pay taxes in Maryland, I really don't much care what they do to the beltway and 270 -- as long as they don't degrade the neighborhoods along the corridor in the process. And that will likely be a showstopper.
I get dogmatic about doing no harm to the neighborhoods because, in the long run, people need to start living closer to their jobs. There are now nearly ten million people in the combined metropolitan statistical area. The 1960's idea that building another high speed commuter sewer is always the first solution should have been abandoned long ago. Degrading close-in neighborhoods to accommodate long distance commuters gets the priorities exactly backwards. Make the older, close-in neighborhoods more attractive to encourage people to move back in. DC itself is full of revitalized neighborhoods where the transition is mind-boggling. The suburban counties need to make this sort of thing their top priority. And as an aside: if we wanted to dramatically change the urban-suburban dynamic overnight, voucher the schools so that people didn't feel they had to flee to the distant suburbs to afford a decent school district.
If I were going to spend money on anything related to the beltway and 270, 66 and 95, I'd focus on more places to cross the interstates. I'm not going to look up the number now, but a very high percentage of trips by automobile are short, under 3 miles, under five miles, under ten miles, etc. At the shorter end of that range, we should be designing neighborhoods that encourage people to get out of their cars. For short trips still requiring a car, spend the highway dollars on making it easier to get around the neighborhoods without getting on the major arterial roads.
The whole transit system is dominated by a spokes and hub approach that has reached maximum capacity. When the hub is choking on traffic, and doesn't have enough parking even after you struggle in after your two hour commute, building bigger feeder pipes from Urbana, Haymarket and Woodbridge isn't a solution. Most of the population lives in the suburbs. A majority of the jobs are in the suburbs. Most of the job growth is in the existing and emerging suburban and edge cities, many of which are becoming densely urban in character. Intersuburban commutes and lateral movement should be the priorities. The spokes and hub model needs to be replaced by a web. And the web needs to be developed with an eye towards intermodal options, so that as many people as possible can be enticed out of their cars.
Maryland had to lengthen the deceleration lane on the Inner Loop for Georgia Avenue South to nearly a mile to accommodate the backups.