The Canyon County Board of Commissioners approved a comprehensive $320 million road improvement plan Wednesday that will fund major construction projects across the county’s transportation network over the next five years, including the long-awaited widening of Highway 20-26 through Nampa and critical intersection upgrades along the Middleton Road corridor. The plan, developed in partnership with the Canyon Highway District, addresses decades of infrastructure underinvestment that has left Canyon County’s roads struggling to keep pace with the Treasure Valley’s explosive population growth.
Canyon County’s population has grown from approximately 188,000 in 2015 to over 248,000 today, a 32% increase that has overwhelmed a road network originally designed for a fraction of that traffic. The Highway 20-26 corridor between Nampa and Caldwell carries over 38,000 vehicles per day — a figure that has nearly doubled in the past decade — and regularly experiences gridlock during rush hours.
What the Road Plan Includes
The centerpiece of the plan is the $85 million Highway 20-26 widening project, which will expand the highway from two lanes to five lanes (two in each direction plus a center turn lane) through the 8-mile stretch between the Garrity Boulevard interchange in Nampa and the 10th Avenue interchange in Caldwell. The project also includes new traffic signals, protected pedestrian crossings, and a separated multi-use path for cyclists and pedestrians.
The Middleton Road corridor, which connects Middleton to Star and Nampa, will receive $42 million in improvements including intersection upgrades at four critical junctions, road widening from two to three lanes, and the construction of two new roundabouts designed to improve traffic flow without requiring traffic signals.
Additional projects include $38 million for Ustick Road improvements between Meridian and Nampa, $28 million for Karcher Road upgrades in Nampa, and $52 million in rural road maintenance and safety improvements throughout unincorporated Canyon County.
Funding Sources and Taxpayer Impact
The $320 million plan is funded through a combination of state highway distribution funds ($128 million), federal transportation grants ($95 million), Canyon Highway District revenue ($62 million), and development impact fees ($35 million). No property tax increase or special levy is required.
Commissioner Leslie Van Beek emphasized that the plan leverages growth to fund growth. “The new residents and businesses moving to Canyon County generate impact fees, fuel taxes, and registration fees that fund these improvements,” Van Beek said. “Growth is paying for the infrastructure that growth demands.”
Impact on Canyon County Commuters and Businesses
The Highway 20-26 widening alone is projected to reduce average commute times between Nampa and Caldwell by 12-15 minutes during peak hours. For the tens of thousands of Canyon County residents who commute to Boise for work, the improvements will also reduce congestion at the I-84 interchange connections, improving travel times across the Treasure Valley.
Local businesses along the Highway 20-26 corridor have expressed both relief and concern — relief that the congestion choking commerce will be addressed, and concern about the 2-3 year construction period during which lane closures and detours could reduce customer traffic. The Canyon Highway District has committed to maintaining access to all businesses throughout construction.
What Comes Next
Design work on the Highway 20-26 project begins immediately, with construction expected to start in spring 2027. The Middleton Road improvements will begin in fall 2026. Residents can review the full plan and submit comments through the Canyon Highway District website at canyonhd.com. Public open houses will be held in Nampa, Caldwell, and Middleton in May. For statewide road infrastructure coverage, see Idaho News.