Study Focus

The Montana Department of Transportation (MDT) initiated a corridor planning process along the MT 78 corridor in order to comprehensively assess future transportation needs, prioritize future transportation projects, and foster cooperative state and local transportation planning efforts. Corridor planning is a relatively new tool within the Montana Department of Transportation (MDT). The MT 78 Corridor Study was funded by the Montana State Legislature to demonstrate that early corridor planning may save the state time and money by giving a context to later planning and environmental compliance documents. The documents below discuss the findings and recommendations for the MT 78 Corridor Study.

Final Report

Entire document (14.2 mb)
Table of Contents
Executive Summary
Sections 1.0 - 3.1
Figure 3.5
Sections 3.1 - 4.2
Figure 4.2
Sections 4.3 - 6.0
Sections 6.1 - 6.2
Section 7.0 - Appendices
Cost Estimates Table

Corridor planning is a process that is collaborative with local governments and includes extensive public participation opportunities. The process is designed to derive a planning-level analysis of the existing transportation system within the corridor and determine how it could be changed to meet long-term needs.

What is the project's primary purpose?

This planning process examined the existing transportation facility and travel characteristics, as well as existing and projected social, economic, and environmental issues within the corridor. The end result of the study is a comprehensive package of recommendations intended to satisfy current design standards, meet mobility and level of service targets, improve safety, and address cost and constructability concerns.

Where was the project be located?

MT 78 is a two-lane highway that begins at the town of Red Lodge and runs through Roscoe, Absarokee, and Columbus before intersecting with Interstate 90. The portion of the highway chosen for this study begins five miles north of Red Lodge and extends to the north end of Roscoe.

Is there a Need for this Project?

The MT 78 alignment between Red Lodge and Roscoe does not meet current design and safety standards. Ninety-seven of the 117 vertical curves within the project limits fail to meet the minimum stopping sight distance (SSD) requirement. Thirty-six of these curves fail to meet the maximum gradient. Fifty-one of the 55 passing opportunities within the project limits fail to meet the minimum passing sight distance (PSD) requirement. Fifteen of the 43 horizontal curves are too tight. As a result of these conditions, the accident rate for the segment is 65 percent higher and the accident severity rate is 62 percent higher than the statewide average for all primary roads. Consequently, there is a need to plan for improvements to this corridor.