The Montana Department of Transportation (MDT) has completed the installation of low noise centerline rumble strips on highways across Western Montana. Crews will briefly return to US 2 this summer to repair sections of the centerline that experienced damage over the winter. Expect short delays, pilot cars, flaggers, and large machinery on US 2 between Pioneer Junction and Happys Inn from the intersection with Arabian Lane to the intersection with Old US 2 South.

Project Overview

The Montana Department of Transportation (MDT) is installing low-noise centerline rumble strips across the Missoula District in western Montana to save lives and reduce roadway departure crashes on Montana's undivided highways. Roadway departure crashes occur when a vehicle crosses into the oncoming lane of traffic or crosses the edge line of the roadway. They are one of the most common and severe types of crash.

Rumble strips are grooves in the pavement that produce a rumbling noise and vibration when a vehicle drives over the strip. Shoulder rumble strips have been utilized on Montana's highways for decades to alert drivers veering off the side of the road. Centerline rumble strips are now being installed along the centerline of undivided highways to continue to improve the safety of Montana's highways.

Centerline rumble strips are designed to prevent roadway departure crashes, particularly head-on and sideswipe crashes that occur when a vehicle crosses the centerline of an undivided highway into the oncoming lane of traffic. On highways across Montana where MDT first installed centerline rumble strips, there is already a significant reduction in crossover crashes.

Benefits of centerline rumble strips:

  • Provide immediate and direct feedback to drivers or motorcyclists unintentionally crossing the centerline of undivided highways, giving distracted or drowsy drivers time to correct course.
  • Act as a guideline to vehicles and snowplows in winter whiteout conditions and other low-visibility conditions.
  • Effective in lowering the number of highway fatalities and serious injuries. In other states where rumble strip projects have been implemented, roadway departure crashes have been reduced as much as 42% and fatal and severe injury crashes as much as 73%.
  • Are a low-cost safety measure. Compared to more than a million dollars per mile of total highway reconstruction cost, centerline rumble strips cost about $5,000 per mile to install.
Low-Noise Centerline Rumble Strips image

Low-Noise Centerline Rumble Strips
Click to view a larger image.

Low-Noise Rumble Strips

Traditional centerline rumble strips have been designed to create noise inside the vehicle, alerting drivers that they are too close to the center of the roadway. They are also loud outside the vehicle, which can be disruptive to residents and businesses close by.

Over the years, the design of centerline rumble strips has improved, and we can now utilize sinusoidal rumble strips – or low-noise rumble strips. Low-noise rumble strips still cause noise and vibration to alert the driver but are much less audible outside the vehicle. Instead of rectangular shapes, low-noise rumble strips are more rounded in shape, decreasing the noise when driven over.

MDT will use the low-noise design in all of the centerline rumble strip installations for this project.

Project Location

Crews will be in western Montana installing low-noise centerline rumble strips in the following locations, click here to view a map:

  • US 2 from just south of Troy to just west of Libby (Lincoln County)
  • US 2 from the junction with Hammer Cutoff Rd to just west of Marion (Flathead County)
  • US 2 south from the junction with MT 35 to the junction with MT 40 (Flathead County)
  • US 2 just east of Columbia Falls to one mile east of Snowslip (Flathead)
  • MT 37 from Rexford east to the junction of US 93 (Lincoln County)
  • MT 37 east of Libby to just west of Jennings (Lincoln County)
  • MT 40 from Whitefish to Columbia Falls (Flathead County)
  • MT 28 from three miles south of Lonepine to Elmo (Lake County)
  • MT 35 from the intersection with US 93 to just before Creston (Lake and Flathead Counties)
  • MT 56 from the intersection with MT 200 to the intersection with US 2 (Lincoln County)
  • S 209 from the intersection with MT 35 to the intersection with MT 83 (Flathead County)
  • S 211 (Round Butte Road) from just West of Ronan to just before Gillette Lane (Lake County)
  • S 292 (Whitefish Stage Road) from the intersection with W Reserve Drive to the intersection with MT 40 (Flathead County)
  • S 352 (Lake Mary Ronan Road) from Dayton to just west of Proctor (Lake County)
  • S 354 from Polson to the intersection with Round Butte Road (Lake County)
  • S 424 from the intersection of N Meridian Rd and Three Mile Drive to the intersection of Farm to Market Road and Lodgepole Road (Flathead County)
  • S 482 (Farm to Market Road) from the intersection with Honeysuckle Lane to the intersection with Airport Way (Lincoln County)
  • S 503 (Airport Road) from the intersection with US 93 to just past the intersection with Shelter Valley Drive (Flathead County)
  • US 93 from just east of Polson to the Canadian border just past Eureka (Lake County)
  • MT 83 from the intersection at MT 200 to the intersection at Junction 209 (Lake and Missoula Counties)
  • MT 135 at St Regis to MT 200 to just past Donlan Flats (Mineral County)
  • MT 200 just north of Thompson Falls through Plains to Perma (Sanders County)
  • S 212 north east of Moise to Kicking Horse (Lake County)
  • Mullan Road from the intersection at Cote Lane to just north of Karl Ct (Missoula County)
  • US 93 South of Hamilton to Missoula (Missoula and Ravalli Counties)
  • US 93 one mile south of Evaro to one mile south of Ronan (Lake County)
  • US 93 from the junction at MT 43 to Dick Creek Trail (Ravalli County)
  • S 269 Eastside Highway (Ravalli)
  • S 203 Eastside Highway to Florence (Ravalli)
  • S 210 (Old Highway 10 E) from Piltzville to McQuarrie Spur (Missoula County)
  • S 474 (Old US 10) from Schilling Siding to Wye (Missoula County)
  • US 12 just east of Lolo from Cowcatcher Drive to Graves Creek Road (Missoula County)

Project Timeline

Installation of the low-noise centerline rumble strips will begin in the fall of 2020 and will be completed in 2021.

Impacts to the Public

MDT is taking measures to be as efficient as possible and create as little disruption as possible during centerline rumble strip installation. MDT will be contacting folks in the installation areas so that they know when and where installations are happening. During construction, traffic will be slowed or stopped as needed to provide a safe environment for traffic and construction personnel. Traffic will be given a clearly defined path through the work zones.

Vision Zero

MDT's Engineering department is tasked with making sure Montana's roadways are engineered to be as safe as possible. That's why engineering is one of the four E's of MDT's Vision Zero initiative, along with education, enforcement and emergency response. We're all working together towards zero fatalities and zero serious injuries on our highways.

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