The Ada County Highway District released a detailed construction timeline and traffic management plan Monday for the $180 million Eagle Road widening project, confirming that the largest road infrastructure investment in Ada County history will break ground in April 2027 and proceed in three phases over approximately four years. The project will transform the heavily congested Eagle Road corridor from Ustick Road to Chinden Boulevard into a modern five-lane arterial with dedicated turn lanes, protected bike lanes, improved pedestrian crossings, and upgraded stormwater infrastructure.
Eagle Road currently carries over 45,000 vehicles per day through the project area — one of the highest traffic volumes on any non-interstate road in Idaho — and the corridor has been identified as the Treasure Valley’s most critical congestion bottleneck in every ACHD transportation study conducted since 2018. The widening has been the single most requested road improvement in ACHD’s annual community surveys for five consecutive years.
Eagle Road Construction Phases and Timeline
ACHD Director Bruce Wong said the project will be constructed in three overlapping phases to minimize disruption while maintaining access to the hundreds of businesses and residential communities along the corridor. Phase 1, covering Eagle Road from Ustick to Fairview Avenue, begins in April 2027 and is expected to take 18 months. Phase 2, from Fairview to Pine Avenue, starts six months after Phase 1 begins. Phase 3, from Pine to Chinden Boulevard, commences in early 2029.
During construction, Eagle Road will maintain at least two lanes of traffic in each direction at all times, with lane shifts and temporary signals managing traffic through active work zones. Most construction will occur during daytime hours on weekdays, though some utility relocation work may require overnight lane closures.
“We know Eagle Road construction is going to affect daily life for thousands of Ada County commuters,” Wong said. “We’ve spent two years planning the phasing specifically to maintain the best possible traffic flow throughout the project. It will be inconvenient, but when it’s done, the corridor will function dramatically better for decades to come.”
What the Finished Eagle Road Will Look Like
The completed corridor will feature five travel lanes — two in each direction with a center turn lane — compared to the current three-lane configuration. Each direction will have a dedicated right-turn lane at major intersections, eliminating the backup caused by turning vehicles blocking through traffic. Protected bike lanes separated from vehicle traffic by a physical buffer will run the full length of the corridor, and ADA-compliant sidewalks will be installed on both sides.
Three new traffic signals will be installed, and five existing signals will be upgraded with adaptive technology that adjusts signal timing in real time based on traffic volume. Stormwater infrastructure will be completely rebuilt to eliminate the flooding that periodically closes Eagle Road during heavy rain events.
Funding and Impact on Ada County Taxpayers
The $180 million project is funded through a combination of state highway distribution funds ($72 million), federal transportation grants ($48 million), ACHD’s capital improvement fund ($35 million), and impact fees collected from new development along the corridor ($25 million). No special property tax levy or bond is required.
ACHD emphasized that the project is being built within existing revenue streams, not through new taxes. However, Commissioner Kent Goldthorpe noted that the project’s scope was possible only because Ada County’s continued growth has generated strong impact fee and registration fee revenue. “Growth is paying for growth in this case,” Goldthorpe said. “The new residents and businesses that have added to the congestion problem are also funding the solution through the fees they pay.”
What Comes Next for Eagle Road and Ada County Commuters
ACHD will host three public open houses in January 2027 — in Meridian, Eagle, and Boise — to present final design plans and answer questions about construction impacts. Businesses along Eagle Road will receive direct notification of construction schedules affecting their locations at least 60 days in advance. Commuters can sign up for real-time construction alerts and detour information at achdidaho.org/eagleroad. Residents with questions or concerns can contact ACHD’s community relations office at 208-387-6100.