West Laurel Interchange

A 2005 summary report from the Montana Department of Transportation (MDT) reported a crash cluster on I-90 near the West Laurel Interchange. In five years time, there were 27 vehicle accidents in the westbound lanes and 48 in the eastbound lanes. By far the most crashes occurred in icy conditions as traffic attempted to negotiate the tight curves on the bridges over the Montana Rail Link (MRL) tracks.

In 2014, MDT made a commitment to “Vision Zero”—a multi-pronged initiative with the goal of eliminating deaths and injuries on Montana highways. This program focuses on four areas: education, enforcement, engineering, and emergency medical response. MDT identified the West Laurel crash cluster as a significant problem requiring an engineered solution.

Working with MDT, Morrison-Maierle pulled resources from our roadway and bridge groups to design new 556-foot and 470-foot curved bridges over the railroad tracks, realign 1.2 miles of interstate, and convert the existing half interchange on I-90 into a full-access interchange. A two-phased effort, this project improved the horizontal and vertical alignments to meet current standards, provided two bridges over the MRL tracks with wide
shoulders, and built a new diamond interchange. The designs eased the sharp curves on the bridges and now not only provide interstate access toward Billings but greatly improves access for Laurel with another grade-separated crossing of the railroad tracks. Together, these improvements are intended to greatly enhance safety and access around the interchange.

Maintaining traffic flow during three years of construction added to the
complexity of the project as I-90 carries 15,000 vehicles per day. As of September 2020, this $32M project now provides a modern interchange for
the Laurel area that is safer and helps MDT move towards its “Vision Zero” initiative.