NO. 1 ROAD: I-15 Technology Corridor

The stretch of I-15 from Lehi Main to S.R. 92 (Timpanogos Highway) is known as the “Tech Corridor” due to the plethora of high-tech development in the area, which is aptly referred to as Silicon Slopes.

With rapid growth in new and ongoing construction of office buildings, restaurants, and homes, in addition to being the main commuter route between the Provo and Salt Lake City metropolitan areas, traffic congestion along the I-15 corridor and nearby surface streets and interchanges was causing inordinate impacts to drivers and the surrounding communities. The Tech Corridor project allowed the Utah DOT (UDOT) to alleviate many of these challenges and vastly improve the interstate, both for today’s travel reality and the future.

The project scope included a new overpass to extend Triumph Boulevard over I-15, conversion of the existing frontage roads to a one-way frontage road system between S.R. 92 and 2100 North, and two fully redesigned interchange systems. The project also involved a total of 17 bridges, two new pedestrian connections over the southbound/northbound frontage roads, a pedestrian undercrossing at the new Triumph Boulevard connection, and new braided ramp structures, which allow for increased mobility between I-15 and the frontage road system. Structure and pavement replacement, capacity increase, and accessibility improvements were the major focuses of the Tech Corridor freeway widening and reconstruction effort. New lanes were added for a total of five general-purpose lanes and one high-occupancy vehicle lane in each direction. In addition, crews reconstructed the interchange at S.R. 92 to add capacity, implementing a more traditional tight diamond configuration that functions in conjunction with the one-way frontage road system. The 2100 North interchange was redesigned and rebuilt to add capacity and accommodate future flyover ramps on the west side to connect to the Mountain View Corridor (MVC), a future 35-mile freeway system under development between I-80 in Salt Lake County and S.R. 73 in Utah County.

The project team added value to this growing area by developing and constructing the first one-way frontage road system of its kind in Utah. The system consists of one-way roads that work in conjunction with three braided slip ramps to access the area directly from I-15 and provide quick access back to I-15. Key to the function of this system is the addition of the Triumph Boulevard bridge connection across I-15 between the S.R. 92 and 2100 North interchanges. The bridge connects the southbound and northbound one-way frontage roads between these two interchanges, cutting the one-way circulation distance in half, and provides a much-needed alternate east-west route. The addition of U-turn lanes at Triumph Boulevard and S.R. 92 further facilitates efficient traffic circulation, reduces travel time, and increases overall capacity of the interchanges by removing left-turn movements out of the S.R. 92 interchange and at Triumph Boulevard. This system provides greater access to and from I-15 and helps disperse traffic from the S.R. 92 and 2100 North interchanges directly to the office complexes of Silicon Slopes, which are the high-traffic generators in the area.

“As you see on most complex roadway projects, traffic capacity decreases and travel time and delays increase through the project area during construction,” said Project Director Boyd Humpherys. “Here, the team instead added an extra lane for I-15 traffic during construction, increasing mainline capacity and saving drivers up to 20% of travel time commute to travel times before construction began. This is a great example of how our project provided benefits to the public during construction of this stretch of I-15. We are proud of the work we accomplished on this project. We alleviated congestion, accommodated for future growth, and created a multimodal transportation system that will keep Utah moving in a variety of ways.”