Advancing Safer and More Connected Mobility in Northern New England

As HNTB’s Northern New England planning and mobility department manager, Ariel Greenlaw helps agencies navigate some of the region’s most complex mobility challenges. Her work with the Maine Department of Transportation (MaineDOT), Maine Turnpike Authority (MTA), New Hampshire Department of Transportation (NHDOT) and Vermont Agency of Transportation (VTrans) includes safety mitigation, corridor planning, signal modernization, operational policy and real‑time traffic and incident management.

Across these efforts, Ariel brings a strong understanding of how technology, data and people intersect, and how agencies can evolve their infrastructure and operations to improve safety, reliability and day-to-day travel for the communities they serve.

Ariel’s leadership is grounded in her technical commitment to advancing the traffic engineering industry and supporting agencies as they modernize their infrastructure. She works closely with peers across the traffic and technology community, mentors young professionals and contributes to conversations around safety, emerging tools and the future of the transportation workforce.

How do you stay connected to the traffic engineering industry, and what trends are shaping the future?

My career has been shaped by the transportation engineering community. Staying engaged in industry organizations helps me track the evolving conversations around data, operations and safety. I remain active in professional groups that bring together traffic engineers, commercial vendors, contractors, data professionals, public‑sector practitioners and other industry partners.

My involvement in ITE – A Community of Transportation Professionals, as a member and in leadership roles, has played an important role in my professional growth. It keeps me connected to peers across the industry, affords leadership and growth training, and provides opportunities to mentor younger professionals.

Across the traffic engineering landscape, I am seeing a clear shift toward data that agencies can act on immediately. Agencies generate millions of data points each day, and the focus now is moving beyond dashboards to tools that translate information into operational decisions such as adjusting signal timing, delivering targeted alerts or adopting adaptive corridor strategies.

My role is to help agencies understand their data, integrate it into daily decision‑making and build the processes and confidence needed to support more responsive, informed infrastructure planning.

With your experience and involvement in complex transportation programs, how do you align operational goals with public expectations during construction?

Clear communication is essential. Whether we’re rebuilding a signal system or replacing a bridge, people want to understand how the work will affect their daily travel and what is being done to keep them safe and their communities functioning during and after construction.

The Veranda Street project is a good example. Using continuous count station data and a coordinated construction detour, the team identified construction windows that minimized overall disruption for the replacement of I-295 over Veranda Street Bridge, even though the work required closing I-295 and Route 1 at one of the busiest locations in the state. Despite careful planning, the closure still had the potential to create substantial regional impacts.

What made the project successful for the public was not eliminating disruption but explaining it clearly. By working with MaineDOT to communicate detour routes, expected delays and, most importantly, how a single weekend of congestion would prevent years of daily commute delays, the project team helped the public understand both the short-term impacts and the long-term benefits. With a clear “why” and consistent, positive messaging, the closure became a shared success story.

Future‑proofing means helping agencies build systems that are flexible, resilient and responsive, whether that’s through smarter operations during construction, safer design standards or policies that adapt to evolving community needs.

– Ariel Greenlaw, PE
Planning and Mobility Department Manager

With safety being the priority, how do you integrate technology and community insight for safe solutions at the local level?

In addition to large‑scale corridor and system improvements, meaningful safety gains can often be achieved through targeted, low‑cost intersection upgrades. By integrating community‑based public involvement with modern technology and data management, agencies can identify and implement improvements that meaningfully reduce crash risk without a significant increase in project cost.

These targeted projects highlight practical countermeasures such as improved signing and markings, signal timing and phasing adjustments, enhanced lighting, access management refinements or detection upgrades that can be implemented quickly and cost‑effectively. When these technical findings are paired with community input collected through tools such as HNTB’s Public Involvement Management Application (PIMA), agencies gain additional insight into how intersections function for all users, including pedestrians, bicyclists, transit riders and emergency services.

This combined approach allows agencies to prioritize design elements that are both technically effective and locally informed, improving safety outcomes while building public trust. In many cases, incorporating these recommendations alongside targeted technology upgrades and early community engagement leads to safer intersections with minimal added cost, reinforcing the value of proactive, data‑driven and people‑centered safety planning.

Where do you see the greatest near‑term opportunities for traffic engineering to improve safety and reliability in the region?

The greatest near-term opportunity is at the intersection of traffic engineering, real‑time operations and system reliability. Agencies like MaineDOT are investing in signal upgrades and corridor innovations that are reshaping how both urban and rural areas manage not just congestion, but day-to-day reliability.

A good example of this is our work on the Ticonic Bridge detour corridor, where we are using signal performance metrics to understand how traffic is actually moving along the route. By monitoring measures such as arrivals on green, queue development and split failures, we can recommend targeted, real-time signal timing adjustments to move traffic more safely and efficiently through the corridor, adjusting as travel patterns vary throughout the year.

This remote monitoring, especially important in rural areas, allows agencies to keep signal systems operating reliably, not just optimally. With connected signal infrastructure, operators can quickly identify detection failures, communication issues or timing problems and address them before they escalate into safety risks or widespread delays. This ability to monitor, diagnose and respond in near-real time reduces unplanned downtime and improves consistency for drivers who rely on these corridors every day.

With millions of data points being captured every minute, every hour, every day, the challenge is no longer collecting data, it is using the data effectively. Technologies such as artificial intelligence can help agencies organize and interpret these data streams, turning raw performance and health metrics into practical, actionable insights that improve safety, reliability and public trust.

How is HNTB supporting agencies as they modernize and future‑proof their systems?

The Gray Village Project is a strong example of how HNTB is supporting agencies as they modernize and future‑proof their transportation systems at the community scale. Working with MaineDOT and the Town of Gray, the project reimagines a complex, vehicle‑oriented village center through realigned intersections, simplified movements and integrated traffic technology to improve safety and mobility for all users. The approach combines roadway geometry changes, signalization, pedestrian and bicycle enhancements, and speed‑management strategies to create a more intuitive and forgiving transportation system. By pairing these physical improvements with modern traffic operations and data‑informed design, the project improves safety for drivers, pedestrians and cyclists while supporting the long‑term vitality of the village. Gray Village demonstrates how targeted, context‑sensitive investments supported by technology and strong community collaboration can deliver meaningful safety and mobility benefits without relying solely on large‑scale infrastructure expansion.

In other cases, modernization happens by rethinking processes, not just infrastructure. NHDOT recently streamlined its driveway permitting process to reduce the time required for development approvals, supporting the state’s goal of expanding housing while maintaining safety standards. By working closely with NHDOT leadership, we helped develop a new approach that allows qualified consultants to perform permit reviews, a task traditionally handled in‑house. While this is a relatively small procedural change, it removes bottlenecks, accelerates much‑needed housing and preserves safety outcomes.

Across all these efforts, future‑proofing means helping agencies build systems that are flexible, resilient and responsive, whether that’s through smarter operations during construction, safer design standards or policies that adapt to evolving community needs. Being able to see those changes take effect in real time and knowing they are making a real difference to how these areas function is incredibly rewarding.