Triangle West warns US‑70, I‑40 corridors will face severe congestion by 2055; commuter rail deemed cost‑prohibitive

Doug Plachinski, executive director of the regional Triangle West transportation planning organization, told the Chatham County Board of Commissioners on March 18 that regional travel‑demand modeling for a 2055 horizon projects large increases in population and employment and widespread congestion without additional interventions.

Plachinski said modeling for a three‑county planning area (Chatham, Durham and Orange counties) shows roughly a 50 percent increase in jobs and more than a doubling of households in the region over the next 30 years under current plans. Several corridors risk “volume‑over‑capacity” failures if only already‑committed projects are built.

Key model results Plachinski highlighted: - US 70 between I‑885 in Durham and the I‑540 outer loop in Wake County is projected to be one of the region’s most chronically congested corridors by 2055. - The stretch of I‑40 at the Durham‑Wake County border will be among the busiest freeway segments in the state by the end of the planning horizon. - Growth patterns outside the three‑county core also contribute to bottlenecks, with traffic pressures extending into Chatham County along major corridors.

Alternatives and tradeoffs: Plachinski described a multi‑scenario analysis that includes a baseline (committed projects), a “shared leadership” scenario that shifts more investment into transit and non‑motorized modes, and an “altogether” scenario that pairs higher transit investment with land‑use strategies to concentrate growth around activity centers and transit nodes. He said the analysis will inform a preferred investment portfolio the MPO will package for federal and state review.

Costs and constraints: The presentation stressed that large federal funding streams created by the Infrastructure Investment and Jobs Act and the Inflation Reduction Act have increased available dollars but also created capacity and delivery challenges. Plachinski said earlier local studies of commuter rail found the capital cost prohibitive because proposed expansions would require new infrastructure on tracks that largely are shared with freight rail, driving costs into the billions.

What the county should expect: Triangle West staff told commissioners the MPO will continue public outreach and refine the preferred scenario; the final metropolitan transportation plan will be submitted to federal agencies for conformity checks and funding eligibility. Plachinski said the MPO will publish more accessible “story map” materials and expects to return to member boards as the plan progresses.

Why it matters: Commissioners heard that the region’s anticipated growth will require coordinated land‑use and transportation strategies to avoid worsening congestion and that there is a narrow window to design investments that pair transit service with denser development around activity centers.

Evidence: Plachinski’s slide deck and the MPO’s travel‑demand model outputs were discussed in detail at the March 18 meeting; he said the modeling runs take roughly a day to complete and that Triangle West will publish interactive maps and data for public review.