Idaho local data guide

Treasure Valley Infrastructure Growth Projects

To accommodate rapid population growth across Ada and Canyon counties, state and regional agencies such as the Idaho Transportation Department (ITD) and the Community Planning Association of Southwest Idaho (COMPASS) are advancing major highway, interchange, corridor widening, and high-capacity transit initiatives.

Updated with grounded research as of 2026-07-21.

The short answer

To accommodate rapid growth across the Treasure Valley, state and regional transportation authorities are advancing major highway extensions, interchange upgrades, arterial road widenings, and long-range planning initiatives. The Idaho Transportation Department (ITD) is leading multi-million-dollar projects under programs like the Transportation Expansion and Congestion Mitigation (TECM) initiative, while the Community Planning Association of Southwest Idaho (COMPASS) coordinates long-term multimodal transportation strategy across Ada and Canyon counties.

Key facts

State Highway 16 Extension & Interchanges: ITD is expanding SH-16 into a major north-south expressway connecting Interstate 84 to SH-44 with full grade-separated interchanges at I-84, Franklin Road, Ustick Road, US-20/26, and SH-44, targeted for full corridor opening by 2027.
TECM Corridor Widening Projects: Through Idaho's Transportation Expansion and Congestion Mitigation (TECM) program, ITD is funding capacity expansion including widening US-20/26 (Middleton to Star) and SH-16 (SH-44 to Beacon Light Road) to four lanes with median barriers.
Regional Transportation Vision (Communities in Motion): COMPASS plans regional transportation for Ada and Canyon counties under its long-range plan (Communities in Motion 2050/2055), forecasting a regional population of 1.3 million by 2055 and prioritizing multi-modal investments in the Regional Transportation Improvement Program (TIP).

State Highway 16 Extension & Interchanges

The extension of State Highway 16 (SH-16) is the Treasure Valley's central north-south freeway addition. Constructed by the Idaho Transportation Department (ITD), the new multi-lane expressway will connect Interstate 84 directly to SH-44, providing a vital north-south link across Ada and Canyon counties.

Supported by State of Idaho Leading Idaho and Transportation Expansion and Congestion Mitigation (TECM) bonding funds, ITD accelerated the construction schedule for full corridor completion targeted for 2027. Full grade-separated interchanges are being constructed at key arterial junctions, including I-84, Franklin Road, Ustick Road, US-20/26 (Chinden Boulevard), and SH-44.

Full limited-access freeway connection spanning from Interstate 84 north to State Highway 44.
Grade-separated interchanges located at I-84, Franklin Road, Ustick Road, US-20/26, and SH-44.
Targeted full corridor opening scheduled for 2027 following accelerated construction timelines.

TECM Corridor Widening Projects

To mitigate growing traffic congestion on heavy commuter corridors, ITD is utilizing the state's Transportation Expansion and Congestion Mitigation (TECM) program to widen key state routes throughout the Treasure Valley.

High-priority widening initiatives include expanding US-20/26 (Chinden Boulevard) between Middleton Road and Star Road to two lanes in both directions with a center turn lane. Additionally, ITD is advancing design and right-of-way planning to widen SH-16 from SH-44 north to Beacon Light Road in Eagle and Star, expanding the route to four lanes with median barriers and overpass structures.

US-20/26 (Chinden West) widening to four lanes with median safety features from Middleton to Star.
SH-16 north expansion from SH-44 to Beacon Light Road, adding four-lane capacity and overpasses.
SH-44 widening projects between Star Road and SH-16 to relieve east-west arterial bottlenecks.

Long-Range Planning: Communities in Motion

Long-range regional planning across Ada and Canyon counties is directed by COMPASS, the metropolitan planning organization for Southwest Idaho. COMPASS develops and updates the regional long-range transportation plan, 'Communities in Motion', every five years to align local growth forecasts with infrastructure investment.

While 'Communities in Motion 2050' serves as the active framework, COMPASS is advancing 'Communities in Motion 2055', which plans for a regional population projected to reach 1.3 million by 2055. COMPASS coordinates funding for highway expansions, public transit, high-capacity transit corridors, and active transportation through the annual Regional Transportation Improvement Program (TIP).

Regional population forecasted by COMPASS to reach 1.3 million across Ada and Canyon counties by 2055.
Integration of multi-modal investments including arterial improvements, transit corridors, and active transportation networks.
Prioritization of regional projects for federal and state grant funding via the multi-year TIP schedule.

Common questions

When will the State Highway 16 extension to Interstate 84 open to traffic?

According to the Idaho Transportation Department (ITD), the full State Highway 16 extension corridor from SH-44 to Interstate 84 is targeted to open to traffic in 2027 following accelerated interchange construction.

What roadway widening projects are planned for Chinden Boulevard (US 20/26)?

ITD is advancing projects to widen US 20/26 (Chinden Boulevard) into a multi-lane divided corridor. Key ongoing and planned segments include widening the highway to four travel lanes with median barriers between Middleton Road and Star Road.

How does COMPASS prioritize regional transportation projects in Ada and Canyon counties?

COMPASS prioritizes projects through its long-range plan (Communities in Motion) and allocates regional federal and state transportation dollars using the Regional Transportation Improvement Program (TIP), evaluating projects based on growth modeling, safety, and multi-modal efficiency.

Sources and verification

Learn More About SH-16 Construction from ITD (itd.idaho.gov)
Explore COMPASS Communities in Motion 2055 (compassidaho.org)