West of Missoula - NW
NWSTPS 263 - 1(28)6
West of Missoula - NW
The Montana Department of Transportation (MDT) is proposing to reconstruct a portion of Mullan Road (Secondary Highway S-263) beginning just north of the intersection with Pulp Mill Road at milepost 10.6 and extending southeast to the east side of the intersection with Deschamps Lane at milepost 5.5. A safety study conducted by MDT has identified the need for safety improvements within the corridor, some of which were constructed in 2014. However, additional roadway improvements are still needed to fully address safety concerns within the project area. The road has a growing traffic demand and, although recent traffic volumes have declined since 2009, traffic volumes are projected to almost double over the next 20 years.
The purpose of the project is to improve the roadway surface and roadside safety by widening the roadway shoulders, flattening the side slopes, and improving the horizontal and vertical alignments. Additional improvements include guardrail replacement, upgraded pavement markings, signing, relocated irrigation features, utility relocations, and new fencing. Traffic studies suggest that the recommended improvements will greatly improve the overall safety of the road.
The roadway currently has two 12-foot lanes (one in each direction) with no shoulders. Based on the traffic volumes, current design standards require a 36-foot paved width, including two 12-foot lanes and 6-foot shoulders on each side of the roadway. The project will be designed to meet these current design standards. The intersection with Deschamps Lane will be reconfigured to decrease the skew angle and improve safety. This project will also examine alternative intersection treatments (e.g., stop sign, traffic signal, roundabout) at the Pulp Mill Road intersection.
The proposed project will require new right-of-way. Utility and irrigation canal relocations will be necessary within the project limits to accommodate these safety improvements. There is one bridge located within the project limits at approximately milepost 7.3 spanning an irrigation canal near Primrose Drive that will be replaced by this project.