The Montana Department of Transportation is considering three main alternatives to the current configuration of the intersection between U.S. 93 Highway South and the U.S. 93 Alternate Route near Basecamp Drive.

The alternatives were developed in collaboration with KLJ Engineering.

Two of the options, according to Project Engineer Dylan McLain, would be unfamiliar to local drivers. Intersections in these formations reportedly don’t exist elsewhere in Montana.

In 2019, MDT performed a traffic study analyzing the southern end of the bypass. At the time, MDT presented four alternatives to the roundabout on Basecamp Drive. But the traffic study revealed a bottleneck issue at the point of entry onto the bypass from U.S. 93 South, which led to another study of that intersection in 2021.

“That prompted us to take a closer look before moving forward with multiple intersection options,” McLain said.

Based on the most recent study, MDT came back with five intersection concepts for the intersection of the U.S. 93 Alternate Route and U.S. 93 South. One possibility is to keep the intersection in its current configuration, and one of the five proposals is no longer in consideration. That leaves three potential alternatives to the current model.

One option is to add a left turn lane for northbound vehicles turning off U.S. 93 onto the bypass. Right turn lanes would be added onto and off of the bypass and turn lanes would be built out on the east approach to U.S. 93.

“Generally the intersection would function much like it does today with additional space for left-turning vehicles to be stored before turning onto the bypass,” McLain said of this option.

However, the additional lanes would create a larger footprint for the intersection.

The next option is one of the two alternatives “where we start to enter unfamiliar territory for many travelers in Montana,” according to McLain.

One configuration involves a separated northbound left turn lane being introduced south of the highway and bypass intersection. Left-turning vehicles traveling on the highway would enter into the separated left turn lane prior to arriving at the bypass intersection in an effort to improve the flow of traffic through the intersection.

The right turn lanes onto and off of the bypass, and the buildout of the eastern entrance onto U.S. 93 South, remain consistent in this alternative and the prior option.

McLain cited improved safety and efficiency as the benefits of this option, but noted the design’s drawbacks are maintenance requirements and lack of familiarity on the part of drivers.

The third alternative is known as a “green T at-grade” design.

This configuration would keep the right turn lanes onto and off of the bypass. It would add a left turn accelerated merge lane without a signal for vehicles headed north onto the highway off of the bypass. Left turn lanes would carry traffic through a signal onto the bypass from U.S. 93.

Northbound traffic would flow freely, without a signal, through the intersection on U.S. 93 South. Southbound traffic on U.S. 93 would be controlled by a signal.

The east approach to U.S. 93 would be limited to a right-in, right-out only entrance.

The advantages and disadvantages of this configuration are similar to the prior option, except the pedestrian crossing would need a flashing beacon since northbound traffic wouldn’t otherwise stop.

The alternative design likely won’t be selected until later in 2022, and funding to build the new intersection isn’t expected to be available for five years, according to McLain.

Visit https://www.mdt.mt.gov/pubinvolve/kalispellbypass/ for more information about the Kalispell Bypass Project.

MDT will hold an in-person open house to discuss the plan at the Hampton Inn Kalispell, 1140 US Highway 2 W, today from 4 to 7 p.m.

Reporter Bret Anne Serbin may be reached at 406-758-4459 or bserbin@dailyinterlake.com.