Re: NorthPoint Cambridge (The one that was train yards, the big plan.)
I have seen recent plans that I have a super crosswalk similar in style to the one in Harvard Square that would connect the relocated T station across McGrath and across Cambridge St. If McGrath Highway were two lanes in each direction with bike lanes or cycle tracks and on-street parking, that would also help to calm traffic.
I would just re-do the whole corridor for traffic calming to reduce the induced demand cramming into Leverett Circle and Storrow, and heal the scar that the horrid overpass created through Brickbottom.
O'Brien Hwy. improvements
-- 2 lanes each direction + bike/bus lane and streetscape from Cambridge St. (intersection will be more spacious when Lechmere's relocated and the El overpass comes down).
Brickbottom area improvements
-- Demolish the overpass, ramps, and highway grading on the Somerville side of the commuter rail bridge so it's back at-grade.
-- Connect Linwood St. to the northbound side after the commuter rail overpass so Brickbottom's less isolated. Keep the Somerville Ave. Ext. underpass to Linwood on the southbound side since it's under the CR bridge anyway, but significantly shorten up the ramp for lower speeds and to reclaim space uselessly wasted by Som. Ave. Ext.
-- Realign so the Som. Ave./Medford St./Poplar St. convergence is an intersection at a new square knitting Union and Brickbottom together.
-- Keep Linwood St. at Washington a one-way (there are other options around) for flow. Do any other flow-related realignments to distribute around the McGrath/Washington/Somerville triangle. I'm also fine with Cross St. remaining blocked from the southbound side...that would be one light too many and too much traffic additional traffic on Cross if a new intersection were put here.
-- Streetscape a median on the wide section through Washington St. up to Medford St. with traffic-calmed Kenmore-style brick + granite crosswalk markings so it's pedestrian-friendly and the "Brickbottom Square" district goes the whole length of the reconnected Medford St. grid. Put on-street parking here.
-- Time the light cycles so these 3 intersections aren't a huge bottleneck. The spacing between lights is pretty good for avoiding that.
East Somerville improvements
-- McGrath down to 2 lanes each direction + bus/bike lane down to Foss Park. Left-turn lanes where needed.
-- Widen the median to something Brighton Ave.-ish and plant some shrubs on it, so crossing at Pearl St. isn't such a terrifying ordeal. Demolish the footbridge and do traffic-calmed crosswalks at Otis Street (this is an induced demand reduction thing...there needs to be a lot more at-grade pedestrian crossing encouraged out to Broadway to lower speeds).
-- Demolish the grade separation on the west side frontage road from Broadway to Pearl. Put on-street parking here with a traffic-separated shoulder a la Beacon St. Brookline to facilitate safe turnouts. I don't think there'll be room for parking on most of McGrath, but putting it here and through "Brickbottom Square" makes it much less an outdated parkway and more a local thoroughfare, which will considerably traffic calm it and reduce the induced demand as a thru route to Boston.
-- Keep the 2 lanes + median out to Blakeley Ave.so that neighborhood can safely cross at the light to Foss Park.
93/38 Interchange and 38/Mystic Ave. flow
-- Take the Mystic Ave. side of the northbound split down to 2 lanes (a little ridiculous that it's a full 3 while 28 traffic only gets 2).
-- Make some access improvements so Mystic Ave. access is less convoluted. The jughandle lights and the west side are a clusterfuck. I don't know how to improve this, but there's got to be some ramp reconfiguration so you can sanely get to 28 south and 38 north.
-- Do something to improve Middlesex Ave. access. Nobody uses this street because continuing south requires a reverse move into the jughandle. Can't there be a U-turn ramp or something so 38 south is actually usable from here?
-- Encourage use of underutilized 38 south as a thru route to Boston via Rutherford Ave. There's never any traffic on it because the frontage road layout is non-intuitive. Better signage, marking this as a truck route, marking this as the thru route to Storrow via Leverett Connector and Memorial Drive via Charlestown Ave., etc. might help. Co-signing Rutherford Ave. as 99/38 down to the Leverett Connector would help point people to it.
-- Improve the traffic flow through the Sullivan rotary so traffic from 38 doesn't get backed up at the lights. Timed light cycles a good start.
-- Long-term plan an underpass from Maffa Way through the parking lot before the Sullivan rotary, merging into the Rutherford Ave. south underpass. Nothing grand, just a little one like Storrow westbound under Leverett Circle. That'll facilitate light-free traffic flow in both directions from Rutherford and Mystic and replace the demolished Sullivan overpass with something a lot less...horrifying and destructive.
Assembly Square
-- Fix the dangerous 38/28 southbound merge so there's not so much traffic weaving to get to Middlesex Ave. The merge ramp's too long and high-speed. It can be shortened up and merged earlier without hosing the Middlesex Ave. intersection.
-- Fix the Middlesex Ave. and Assembly access road intersections so they aren't so ramp-y and meet at 90-degree angles for safer, lower-speed movements.
-- Time the light cycles here.
-- Knock Fellsway down to 2 lanes each direction + bus lanes out to the Medford side and the President's Landing intersection. Widen the bridge sidewalks a couple feet so that's a less foreboding walk over the Mystic. That'll keep the traffic-calming sanity going from Assembly to Station Landing and keep those two developments plus East Somerville across the street from being completely cut off from each other.
-- Back as-is from President's Landing on out. The 16 rotary boondoggle is the state's problem, and Fellsway north to 93 is laid out pretty OK save for maybe some bike lane, crosswalk, and light cycle improvements.
I think this lops off a huge amount of induced demand plowing through to Leverett and Storrow, seriously improves traffic flow into Boston, and births a whole new square in Somerville that knits Brickbottom and Union back together and Somerville and Northpoint.
