Re: Porter Sq
Quick fixes coming to Porter Square intersection, including reducing 5 light phases to 3 and simplifying some lanes:
I assume the three phases have to be:
- Straight on Mass Ave in both directions
- Somerville Ave to Mass Ave, both left and right turns
- Left from southbound Mass Ave to Somerville Ave
(Apparently left turns from Somerville Ave to Mass Ave are currently disallowed, but the plan is to allow them in the future to compensate for the loss of the mall exit left turn, judging from the article's photo showing a future left turn arrow in blue and the existing right only white arrows on the pavement in the satellite photo)
Given that basic arrangement, the pedestrian crosswalk to cross Somerville Ave on the east side of Mass Ave has to be simultaneous with traffic going straight; will right turns from Mass Ave to Somerville Ave have a dedicated turn lane that gets a green simultaneous with Somerville Ave getting a green?
Also, it appears that this means that during the left turn from Mass Ave southbound to Somerville Ave is the only time pedestrians can cross Mass Ave, which implies that Mass Ave southbound straight through traffic will have to get red during that phase.
How are bicycle left turns from Somerville Ave onto Mass Ave toward Harvard expected to work?
I think if the plaza gets rebuilt it would be good to use some of its space for a protected cycle track running from White St to the remaining right turn only exit from the mall to Mass Ave. Hopefully we get cycle tracks along Mass Ave along the lines of the proposal at
http://amateurplanner.blogspot.com/2016/02/a-complete-mass-ave-in-cambridge.html at some point for that to connect to.
Does Somerville Ave need its second eastbound lane between Mass Ave and White St?
It would be ideal to have both a protected cycle track and loading zone space on the eastbound side of Somerville Ave just to the east of White St in addition to the travel lane there, but I'm not sure if there's enough road width to make that work. (Maybe eliminating the second westbound lane just east of White St might work, although the 83 bus stop in that vicinity does need to be maintained somehow. The other question is whether the travel lanes are wide enough that they could be narrowed, etc.)
It might also be possible to reconfigure the plaza to provide a separated right turn lane from Somerville Ave to Mass Ave on a more direct path sort of like how the Wilson Sq right turn from Somerville Ave to Elm St works (but probably without copying Wilson Sq's parking). It might also make sense to move the 83 bus stop into that area.