Idaho’s First SPUI – I-84 Vista Interchange
Stanley Consultants was hired to design a new interchange on Interstate 84 to alleviate traffic flow problems and increase safety.
Innovation in the form of Idaho's first Single Point Urban Interchange (SPUI) has come to Boise at the I-84 Vista Avenue interchange. Pronounced "Spooey," the Single-Point Urban Interchange is a relatively new variant of the diamond interchange.
Interstate 84 is the backbone of the Treasure Valley's transportation system. It serves as a vital freight corridor, being the primary connection between the Pacific Northwest and the Intermountain West. The Vista Avenue Interchange on I-84 is an important gateway to Boise, and is a major point of access between the Boise airport, the city of Boise and the region. Built in 1969, the existing interchange was unable to efficiently handle the current volume of traffic and the structure interfered with the needed widening of I-84.
Reconstruction of the interchange is the centerpiece of the state's GARVEE Transportation Program. It is one of eight projects throughout the state designed to create jobs, stimulate economic activity, improve motorist safety and reduce congestion. Preliminary and final design was completed in just 9 months.
The project encompasses the following transportation benefits:
- Compact layout required minimal right-of-way acquisition
- A single traffic light reduces delays and allows concurrent left turns
- Widening adds dual left turn lanes and dedicated right turn lanes
- Wider and longer on and off ramps to I-84 enhance safety
- Sidewalks and bicycle lanes