Arborway: Yes! DCR Designates Alternative 4 As “Preferred”

Of the four alternatives for redesigning Arborway presented in January, 2022, I am very pleased that the DCR has announced that Alternative 4 is its preferred alternative. Alternative 4’s main features are signalized intersections in place of the two large, existing traffic circles (Kelly Circle, Murray Circle); a continuous bike path along the west side of Arborway; and revised roadways and intersections that will effectively keep through traffic off the northbound carriage road.

In my February 8 public comments regarding the four alternatives, I explained why the essential features of Alternatives 1, 2, and 3 are fundamentally unsafe. Alternative 1 and the southern half of Alternative 2 invove multilane roundabouts, which are inherently unsafe because they involve pedestrians crossing multilane exits. The interim safety improvements the DCR made about 2 years ago got rid of one of those deadly multilane exits; it is inconceivable that they’d make a permanent design with this known safety hazard. Alternative 4 is clearly superior in terms of all of the project’s goals: safety, especially for pedestrians and cyclists; providing connected pathways for park users on bike and on foot; minimizing the road footprint and restoring parkland; and providing a reasonable amount of road capacity.

Still, my February 8 comments list a number of ways in which Alternative 4 needs to be improved, and I hope that as the design progresses, these ideas will be incorporated. They include:

  • (From my comment 3) At the new Murray intersection, Centre St NB needs a right turn lane with its own signal phase, so that the east-side pedestrian crossing can run concurrenty with NB Centre thru and without conflicts with the heavy right turn volume.
  • (From my comment 4) At the new Murray intersection, where bikes/peds cross the slip lane for Arborway SB, that crossing must be signalized and must have a very short cycle (e.g., 25 s off-peak, 35 s peak) because it’s part of a multistage crossing, and unless the cycle is very short, delay will become so long that people will not wait for the Walk phase. .
  • (From my comment 5) The right turn lane for the main barrel SB at Murray is too short – it will spill back into the thru lanes, undermining the capacity of the thru phase. Consider merging the SB Carriage Road with the main barrel at the driveway between 71 and 75 Arborway, and then lengthening the right turn lane on the main barrel SB approaching the Murray intersection so that the very heavy right turn flow doesn’t spill back and block thru traffic from using the thru lanes. The SB Carriage Road from the new merge point to the last driveway, at 79-81 Arborway, would then be a cul de sac.
  • (Related to my comment 7) A bicycle route along the east side (city side) of Arborway is needed as well as along the west side. For much of the distance from Eliott Street to Centre Street, this can be accomplished by allowing contraflow cycling on the NB Carriage Road and on “little Pond Street” (the service road that intersects with Orchard and Dunster), and providing a path connector between those two service roads, as shown in Alternative 3. Both of those service roads will have very little traffic, and so they can serve as a bike route. (And young children can use the sidewalk.)
  • (Related to my comment 8) A main barrel crossing is needed at Parkman. The proposed crossings are too far apart, and so people will cross at Parkman; they need the protection of a formal crossing. Because nearly all Parkman and Pond Street traffic headed southbound will use the SB Carriage Road, there will be few right turns from Parkman onto the main barrel, which would allow a concurrent pedestrian crossing there. You could even consider banning right turns from Parkman where it meets the main barrel.
  • (Related to my comment 10) It is still not clear how the bike crossing at the miniroundabout can be made safe. I look forward to seeing the solution the DCR and its consultants propose. Another option they should consider is replacing Alternative 4’s miniroundabout with the small signalized intersection that is part of Alternative 2 (but with the Parkman Drive extension meeting the main barrel at Prince Street, as it does in Alternative 4 – see my comment 13).
  • (Related to my comment 14) Upper Arborway needs advisory lanes (which also involves centerline removal) so that there will be a continuous bike route on the east side of Arborway as well as west.
  • (Related to my comment 16) At the intersection of Upper Arborway with Centre, a median island will facilitate safe crossings better than a raised intersection.

Posted September 10, 2022