Roundabouts; auxiliary lane; rerouting frontage road considered for Gore Hill
Plans to improve the Gore Hill interchange are still in the development phase, but the Montana Department of Transportation has identified the preferred alternative.
MDT officials and its consultants held an open house Thursday afternoon to share information about the proposed design and answer questions.
The proposed project includes replacing the current stop controlled intersections on both ends of the bridge over the interstate with single lane roundabouts; adding an auxiliary third lane on I-15 southbound between the 10th Avenue South and Gore Hill interchanges; and relocating the frontage road.
Scott Randall, a project engineer with Robert Peccia and Associates, said MDT is still evaluating the bridge and looking at options including leaving it as is, widening, or constructing a new bridge.
The Gore Hill interchange project is complex and requires a lengthy project development process to examine options before construction begins, according to MDT, and public input is a part of the process.
The interchange has long been an area of concern for the Great Falls community due to issues with operations, geometrics, safety and access.
According to MDT, there have been 21 crashes at the Gore Hill interchange. Eight of those were rearend crashes and seven were right angle crashes. Seventy-one percent occurred during daylight areas and 43 percent when the roads were icy, snowy or wet.
The auxiliary lane is recommended since about 50 percent of vehicles entering I-15 at 10th Avenue exit at the Gore Hill interchange and the lane would reduce conflicts with vehicles merging and exiting. It would also accommodate larger trucks and slow moving vehicles between the two interchanges.
The single lane roundabout is the preferred option at this point. Other options considered were a five-leg roundabout, two-lane exit, right turn slip lane, traffic signal, dual lane roundabout, reroute the frontage road, stop signs and a dedicated left turn lane.
In 2015, MDT developed the I-15 Gore Hill to Emerson Junction Corridor Planning Study in partnership with the Federal Highway Administration and in coordination with the Great Falls Metropolitan Planning Organization.
The purpose of the study was to determine potential improvement options to address safety and operational concerns within the interstate system through Great Falls.
The report identified recommendations to address the transportation needs in the area through the planning horizon of 2035.
Among the recommended improvement options were the addition of a southbound auxiliary lane between the Gore Hill and 10th Avenue South Interchanges and intersection improvements at the Gore Hill Interchange.
The Great Falls Long Range Transportation Plan 2018 Update also included recommendations to make improvements to the Gore Hill Interchange as outlined in the Corridor Planning Study. Various public involvement strategies were used to engage key stakeholders and the public throughout these past planning efforts.
The area around the interchange has been developing and Randall said they used aggressive growth in their future traffic projections.
Love’s Travel Stop is planning a new station at the Gore Hill interchange. That project has already been approved for a sign variance and will be working through the city’s annexation process.
Randall said they met with business and property owners around the project area this week as well as the public meeting and at least 50-60 people had come through the open house events by early Thursday afternoon.
MDT will use the community feedback to make determinations on the proposal and bridge and then move into the design phase.