Engineers present Baker/Main Street redesign emphasizing signal upgrades, pedestrian improvements and constrained bike accommodations

Jacobs engineers on May 5 presented a draft final design for the Baker Avenue/Main Street intersection to the Town of Concord Transportation Advisory Committee, outlining signal upgrades, geometric adjustments and pedestrian and bicycle accommodations intended to improve safety while fitting into existing right-of-way constraints.

The consultants proposed new traffic signal equipment, retroreflective backplates and an advanced protected left-turn phase for the eastbound left into Baker Avenue during the evening peak. "We determined it would be good to leave that left turn lane," Jacobs traffic lead Erica Lindberg said, adding the PM peak would receive a protected left-arrow phase. The team also recommended retaining a signalized intersection with an exclusive pedestrian phase, countdown pedestrian heads and APS accessible pedestrian signals to aid visually impaired users.

Jacobs engineers said a dedicated 5-foot striped bike lane was infeasible within the current right-of-way. Instead, they recommended narrowing through lanes from 11 to 10 feet to provide roughly 3.5-foot paved shoulders and bicycle detection at the stop bars. "In order to provide a dedicated bicycle facility would need five-foot wide bike shoulders. We are only able to add a three-and-a-half-foot shoulder here," Lindberg told the committee.

Designers outlined geometric changes at the Old Bridge/Crest Street area, including removing a small island and combining two access points to improve visibility and emergency-vehicle turning. They said the changes would allow some previously prohibited left turns but acknowledged members’ concerns about driver warning signs and intuitiveness.

TAC members and public commenters pressed Jacobs on practicable safety measures: storage length for the left-turn lane (Jacobs estimated about 50 feet, two vehicles), how bicycle detection would function (optical/video detection to call phases at the stop bar), and whether two-stage bicycle turn boxes might be added. "Bicycle detection at the stop bars would pick up a bicyclist so they could get the phase," Jacobs said.

Several committee members and commenters urged stronger, low-cost measures in addition to the engineering work. Phil, a TAC member, said the intersection will only get busier as nearby developments come online and asked the team to ‘‘lean forward’’ on safety. Members suggested marking shared-lane pavement, 'don't block the box' striping for peak hours and clear signage across the bridge to alert drivers to bicyclists.

Jacobs identified utility pole and right-of-way constraints—particularly near the Chase Bank curb cut—that limit geometric options. Presenters said a land-swap with neighboring property owners is under consideration to place signal cabinets and maintain overhead utility alignment. The consultants asked TAC for written comments within one week so the team can incorporate adjustments into a final submission and get the project out to bid.

Town staff underscored schedule pressure: Steve (staff) told the committee that construction funding for the project must be spent this year and is otherwise at risk of lapsing. "That money expires at the end of the year," he warned, urging timely resolution and rapid incorporation of TAC feedback.

Next steps: Jacobs will incorporate TAC input and written public responses into a revised plan set; staff and Jacobs agreed to deliver the consultants’ written responses to public outreach directly to TAC. The committee asked staff to consolidate member comments and pass them to Jacobs via Christine Zale to streamline the review.