Commuter Meets Environmental Engineer: A Profile on Public Works’ Diane Stokes

Day after day, Cambridge resident and environmental engineer Diane Stokes biked along Massachusetts Avenue to drop off and pick up her daughter from school, both consciously and subconsciously noting different pain points in her commute. Her analytical mindset and field expertise made her acutely aware of even the smallest inconveniences along this major City artery.

Massachusetts Avenue, stretching approximately 3.5 miles through Cambridge from Memorial Drive to Alewife Brook Parkway, is notorious for its transportation challenges, which many residents have reluctantly grown accustomed to. Yet, Stokes, who has traveled Mass Ave for years from her younger days working as a bank teller in Harvard Square to now escorting her daughter to and from school, is at the center of being able to effect its change.

As the Director of Engineering Services in the Department of Public Works (DPW), Stokes has been leading the engineering design efforts of Cambridge’s Mass Ave Partial Construction Project since its inception. This project, in fulfillment of the 2019 Cycling Safety Ordinance, aims to create street infrastructure that accommodates all modes of transport while supporting the needs of local businesses along the corridor.

For Kathy Watkins, the Commissioner of Public Works, approaching Stokes to drive the project forward in this colossal undertaking was a clear choice. Stokes’ local commuter perspective and experience with large multidisciplinary infrastructure projects made her the ideal candidate.

In her signature work boots, work pants, and bohemian headband, Stokes’ passion for engineering—and its many interconnected challenges—is unbridled. When Stokes joined the Cambridge DPW team in 2014, she immediately got involved with the City’s Western Avenue Reconstruction Project which was initiated to address wet weather surcharging and flooding. The project also aimed to enhance the functionality, safety, and aesthetics of Western Avenue, another key thoroughfare in Cambridge.

“Every time I ride down the cycle track [on Western Ave.] now, I’m always looking at the condition of the pavement and checking on Riverside Place”, a short, narrow and flat dead-end street off Western Ave - characteristics that make collecting surface runoff challenging. The design was changed to locate the catch basins in the middle of the road with a slight slope towards the catch basins. “It’s actually been considered for some of the shared street designs that they’re doing now, so that’s really satisfying. ”

By the time the Mass Ave Partial Construction Project was initiated, Stokes was already a seasoned Mass Ave commuter. She discovered early on that the bus frequency along Mass Ave wasn’t reliable enough for her schedule—one of the issues the project aims to address—so she resorted to primarily walking and biking and minimized the use of her car. Through biking, Stokes identified areas on Mass Ave where she felt unsafe biking in the street without separated bike lanes.

In preparation for the project, Stokes intentionally began driving more to experience Mass Ave traffic patterns at all times of the day. This practice allowed her to pinpoint choke points, such as where a left-turn lane should be extended, where the biggest conflicts between bikes and right-turning vehicles occur, and where additional crosswalks are needed based on frequent pedestrian crossings.

As a result, when Watkins asked for her initial project insights, Stokes was ready and quickly identified areas that could be improved based on her experience traveling through the project area.

Stokes said the initial project meetings focused more on the street design, but her “user perspective” helped the project team better understand the project’s needs and focus their efforts. With a deep passion for municipal engineering, Stokes emphasized the importance of evaluating underground infrastructure and developing a surface design that can be constructed over existing subsurface conditions. “I love the role I have of being able to bridge the gap between engineering and streets and sewer maintenance,” said Stokes.

Acknowledging that there are many different competing priorities in the City, Stokes said “… we have to really think through how we phase the project and how it’s funded over a number of fiscal years.” The first phase of the construction will be focused on utility repairs primarily between Roseland Street and Waterhouse Street with some other repairs along the corridor. A construction bid package is being prepared, and construction is expected to begin in early 2025.

As Stokes’ influence in DPW projects became more widely known, neighbors and other community members began approaching her with transportation safety concerns throughout Cambridge. Stokes’ observations and community engagement highlight the value of employees who both work and live in the City, as their firsthand experiences and multiple points of contact greatly enhance their ability to tackle transformative projects.

“It’s a huge touchpoint,” she said. “We’re not just fixing today’s problems; we’re looking to the future, 25, even 100 years out. We’re building this for the next generation.”