A Cost-Effective Solution for Increased Safety

Interstate 90 is a vital east-west transportation corridor through the Rocky Mountains, and any traffic interruption adversely impacts traffic and commerce. In western Montana, of a particular issue is the ongoing threat of landslides on the shoulder and roadways.

In spring 2013, unusually wet conditions caused several large rockslide areas between mileposts 24.1 and 24.6 on Interstate 90. A large boulder rolled onto the highway at one location, causing a severe accident. MDT immediately installed temporary rock containment rails, cleared the interstate, and undertook a highly technical slope stabilization construction. They decided to pursue a design-build process that allowed them to move ahead at an accelerated pace due to the unstable conditions.

In spring 2014, a third slide closed down the westbound lanes at milepost 6.5, resulting in a long-term closure of the westbound lanes. The proximity of this incident allowed the engineering team to quickly address this problem, and they added it to the current project.