RPA conducted a comprehensive evaluation of existing and future conditions along the US 191 corridor, including travel time data, traffic volumes, and vehicle classification to assess congestion and operational performance. Roadway geometrics, crash history, and wildlife-vehicle conflict data were analyzed to identify safety trends, contributing factors, and locations with substandard conditions.

The corridor’s location within the Gallatin Canyon also presents significant environmental and physical constraints, limiting large-scale improvements and requiring careful consideration of impacts to the Gallatin River corridor and surrounding habitats.

Safety and mobility improvements were developed based on these findings, including intersection enhancements, turn lanes, shoulder widening, updated traffic control, and wildlife accommodations. The study also considered multimodal opportunities such as transit enhancements and shared-use facilities to reduce single-occupant vehicle demand without requiring major capacity upgrades.

Extensive public and stakeholder engagement was conducted to address the high level of interest in the corridor. Outreach included both in-person and virtual efforts, allowing the project team to gather input from a broad range of users and stakeholders.

The study identified a range of improvement options from low-cost operational enhancements to long-term corridor strategies, providing MDT with a flexible framework to guide future investments. The resulting plan supports improved safety, mobility, and system performance while balancing environmental constraints and community priorities.