State DOT presents Route 3 redesign; proposes three single‑lane roundabouts for 1.7‑mile corridor

The New Hampshire Department of Transportation on Aug. 13 presented conceptual plans to the Bedford Town Council for improvements to South River Road (U.S. Route 3) from the airport access interchange north to Hawthorne Drive and recommended a roundabout-based design that the DOT said best meets the project’s safety, mobility and active-transportation goals.

David Smith, the DOT project manager, and Keith Coda of HDR, the DOT consultant, described a 1.7-mile project corridor where traffic volumes vary from about 21,000 average daily trips on the west end to about 10,000 at the southern limit. After traffic counts and crash analysis, the project team presented two build alternatives — a conventional signal/unsignalized approach with raised medians, sidewalks and shoulders, and a roundabout alternative that would place three single‑lane roundabouts roughly 1,200 feet apart and add sidewalks, 5-foot bike shoulders and stormwater treatment basins.

DOT said the roundabout alternative met more elements of the project purpose and need — reducing crashes, improving pedestrian and bicycle accommodations, improving access management and addressing deficient roadway geometry — and noted roundabouts typically reduce the number and severity of crashes by eliminating many vehicle conflict points. The DOT estimated construction costs at about $20.6 million for the roundabout scheme; the state’s 10-year program currently lists $21.4 million for the project.

The DOT and consultant described outreach to a 15-member public advisory committee (PAC) that included residents, business owners and town staff, plus meetings with local police and fire chiefs. Workshop materials and local case studies were used to address fire and emergency‑response concerns. Smith said the DOT and HDR contacted fire chiefs in Pelham, Keene and other towns who reported that single‑lane roundabouts did not impede emergency response and that their communities had seen reductions in severe-injury crashes after roundabout installation.

Councilors asked about sight distances, bicycle routing, the long-term capacity of the single‑lane roundabouts and alternatives if regional development increases traffic beyond design projections. Keith Coda said the design is sized to carry traffic to a 20‑year design horizon using a 1% annual growth assumption and traffic from planned developments; DOT officials said the roundabout alternative is projected to operate at a high level of service under modeled future traffic. The consultants described design features for bicyclists: shared-use widened sidewalks and ramps that enable cyclists to cross roundabouts on marked crosswalks, while noting aggressive cyclists may remain in the travel lanes at their own risk.

Council response was mixed but broadly receptive. Several councilors expressed support for the roundabout approach and asked DOT to return with more visuals (aerial examples and local precedents) and detailed vehicle-tracking runs for fire apparatus. DOT said its next steps are continued environmental analysis, a public informational meeting in October or November, a draft NEPA document and a public hearing in early 2026, followed by final design and right‑of‑way acquisition if the project is approved. DOT staff asked the council for a finding of support to advance the project; no formal council vote on support was recorded at the meeting.

If advanced, DOT estimated advertisement for construction would be feasible in 2028; final design would take roughly 12–14 months and right‑of‑way acquisition would follow. The DOT emphasized that the project must meet signal-warrant, environmental and design criteria to obtain NEPA approval and that additional future development could require further projects or developer-funded mitigation.