Minnesota Department of Transportation

511 Travel Info

Research & Innovation

Return to need statements home page

NS767: Best practice for seal coating and pavement markings with rumble/mumble strips

Problem and objectives

Sinusoidal rumble and mumble strips are an important safety countermeasure that can help drivers recover after inadvertently leaving the traveled lane. There is a great deal of research on the impact to pavement integrity with the introduction of rumble or mumble strips, but limited, definitive research on the safety effectiveness of the rumble or mumble strips after a seal coat is applied on a pavement and understanding the rumble or mumble strip performance and, consequently, whether driver safety is compromised.

This project will study the effectiveness of sinusoidal rumbles after chip seal installation; and determine if there are strategies to preserve the safety countermeasure effectiveness of the sinusoidal rumbles following a chip seal.  Additionally, there are inconsistencies with MnDOT guidance and practice.  For instance, there is a MnDOT technical memo that discourages the use of chip seals over rumble and mumble strips, yet some MnDOT districts are actively doing this work and experiencing presumably acceptable results. Other agencies, such as the Michigan DOT are using rumble strips with additional grinding to 5/8” depth, in anticipation of future chip seals. Local agencies are in search of validation of rumble or mumble strip effectiveness after seal coat, and developing best practices  associated with pavement maintenance and preserving rumble or mumble strip effectiveness.

The research team will:

  • Review current literature, best practices, and regulations or guidance regarding rumble and mumble strips and related pavement markings with the use of chip seals or other surface treatments
  • Survey local agencies, MnDOT Districts and other agencies as needed (e.g., Michigan DOT) to understand who is and is not using chips seals on roadways with rumble or mumble strips
  • Identify case studies where roadways with rumble and mumble strips have received a chip seal in MN
  • Conduct tests to show how chip seals impact rumble and mumble strips effectiveness if definitive results are not found in literature
  • Identify mitigation strategies to protect the investment into safety countermeasures like rumble or mumble strips that could be incorporated into pavement preservation projects

Suggested deliverables

  • Develop a guidebook or best practices summary for using seal coats and chip seals on roadways with rumble or mumble strips
  • Research report detailing study findings

Expected benefits

The numbers 1 and 2 indicate whether the source of the benefit measurement is from: 

  1. A specific research task in your project that supports measuring this particular benefit, or
  2. Implementation of the research findings (anticipating positive results)
  • Decrease Engineering/Administrative Cost (2):
    • Guidance may assist staff in determining optimal design and timing of treatments
  • Decrease Lifecycle Costs (2):
    • Guidance may support optimal design and timing of treatments
  • Increase Lifecycle (2):
    • Guidance may support optimal design and timing of treatments
  • Operation and Maintenance Saving (2):
    • Guidance may support optimal design and timing of treatments
  • Safety (1):
    • Guidance may support optimal design and timing of treatments for desired safety benefits
  • Risk Management (1):
    • Guidance may address the integrity of the rumble and surface treatment relative to safety performance.

Previous research

MnDOT Library Literature search

Resources searched: TRID
Determine best practice of the use of sinusoidal rumbles and chip sealing. Study the effectiveness of the sinusoidal rumbles after chip seal installation; develop a decision process/model on how to implement these project types effectively when ideal timing is not always possible. Secondly, determine if there is a profile that could be milled to allow the use of sinusoidal followed by a chip seal. Thirdly, review MnDOT Tech Memo discouraging the use of chip seal over rumbles vs what is actually being done (MnDOT districts in the South of the state may be chip sealing over sinusoidal rumbles and having acceptable results); Michigan DOT grinds rumbles to 5/8” depth in anticipation of future chip seals (standard rumbles).
Key words: Sinusoidal rumbles, mumble strips, seal coating, Chip sealing, Chip seal over rumbles
Summary: Results are compiled from the databases named above.  Links are provided for full text, if applicable, or to the full record citation.  I completed my searches using the following terminology: Sinusoidal, sinusoidal rumble strips AND chip seals, rumble strips AND chip seals; seal coats AND rumble strips AND maintenance; rumble strips and pavement  

Completed Research
Title: Centerline Rumble Strip Effects on Pavement Performance

Authors: Coleri, Erdem; Chitnis, Vipul; Weaver, Joshua
Source: Oregon Department of Transportation, 2023
Link: https://rosap.ntl.bts.gov/view/dot/67650
Abstract: Despite numerous research studies inspecting the safety benefits of CLRS on pavements, there has been limited exploration into the impact on pavement durability as a result of the installation of CLRS. The major purpose of this study was to corroborate what specific factors are controlling the cracking failures due to the installation of CLRS and find solutions to mitigate CLRS-related failures on the roadway. The first component of the study was Finite Element Analysis (FEA) modeling. FEA was conducted to simulate moving tire loads over a full-scale asphalt pavement section containing CLRS. The optimal CLRS configuration included sinusoidal rumble strips installed adjacent to the longitudinal joint with a shorter wavelength. The FEA results verified the findings of the laboratory testing while allowing for the examination of additional factors not tested in the laboratory component of this study. In the second phase of this study, a test strip was constructed at the Knife River facility in Corvallis, Oregon where CLRS were milled into the asphalt pavement. The primary findings showed that sinusoidal CLRS had optimal performance, shallower and smaller rumble strips had a less structural impact, and chip seal surface treatment is an effective method to prevent moisture infiltration, which is expected to be a major factor controlling CLRS performance. The next portion of the study was X-ray Computed Tomography (CT) imaging to determine the presence of microcracks in the asphalt pavement due to rumble strip milling. Results demonstrated the presence of microcracks at all milled rumble strip locations. This finding pointed out the importance of applying a surface treatment on the CLRS right after installation to reduce moisture-related cracking failures. Potential failure mechanisms and construction recommendations were developed based on the results of laboratory testing, X-ray CT imaging, and FEA.

Title: Developing methods and strategies to reduce the impact of rumble strips (RS) on pavement performance

Authors: Coleri, Erdem; Chitnis, Vipul; Weaver, Joshua
Source: International Journal of Pavement Engineering
Link: https://doi.org/10.1080/10298436.2023.2188593 (Contact Library for access)
Abstract: Despite numerous research studies inspecting the safety benefits of centreline and shoulder rumble strips (RS) on pavements, there has been limited exploration into the impact on pavement durability due to the installation of RS. The RS milling process creates micro-cracks in the pavement structure that could propagate to macro cracks over time with freeze and thaw, moisture damage, and traffic loading, thereby decreasing the lifespan of the pavements. The primary objective of this study was to develop testing procedures for RS samples as well as analysis methods to determine the impact of potential controlling factors such as permeability and resulting moisture damage; freeze–thaw; the presence of microcracks; surface layer sealants (chip seal); RS size, depth, type, and RS location in relation to the longitudinal construction joint. The flexural beam fatigue test suggests that sinusoidal rumble strips had 38% increased fatigue cracking resistance. Moreover, the sinusoidal rumble strip resulted in 41% improved cracking and structural performance in the Hamburg Wheel Tracking Test (HWTT) tests. Also, the rutting performance of sinusoidal rumble strips was similar to the control section without rumble strips. In addition, 0% moisture infiltration was observed in sinusoidal rumble strip specimens.

Title: Impact of Rumble Strips on Longitudinal Joint Pavement Performance

Authors: Katie Haslett DeCarlo; Todd Thomas; Jason Wielinski
Source: Transportation Research Record, 2023
Link: https://doi.org/10.1177/03611981231163774
Abstract: Milled centerline rumble strips are commonly used to reduce lane departure crashes. Safety benefits of installing rumble strips are viewed as a higher priority than the potential impacts to longitudinal joint performance, often leading to a reduced pavement life. There are several different approaches to minimize the impact that rumble strips may have on joint performance, such as careful selection of pavement candidates for installation of rumble strips, using a sealant on top of the rumble strip (top-down) or using a joint sealer (bottom-up). The objective of this study was to assess the impact of using a void reducing asphalt membrane (VRAM) as a joint sealer on longitudinal joint performance with and without the addition of rumble strips. Laboratory testing was completed on plant mix lab compacted specimens and field cores sampled along the centerline joint of two different roadways. Testing consisted of low and intermediate temperature cracking tests and permeability testing. Results from this study showed that VRAM was effective in mitigating increased permeability concerns with the addition of rumble strips into the pavement surface. In relation to laboratory cracking results, there was no significant difference observed between cracking tolerance index (CT-Index) values with and without rumble strips for cores sampled from one project location, while the second project location showed that CT-Index increased with the presence of the VRAM. Continued monitoring of field sections included in this study and future trial sections will be beneficial in understanding the link between laboratory testing, field performance, and variability associated with centerline joint performance.

Title: Evaluation of the Performance of Rumble Strips on Pavements Where Seal Coats Have Been Applied

Organization: Texas Department of Transportation, 2022
Description: The goal of this project is to determine how many layers of seal coat can be applied on a pavement with rumble strips before rumble strip performance and, consequently, driver safety is compromised. Researchers will: 1) Review the literature for rumble strip performance thresholds for safety specifically relating to noise and vibration. 2) Develop a field-based testing plan using a statistical D-optimal design methodology. The plan will either be a before-after design of several projects scheduled for seal coat construction, or a repeated measures design of a few projects with controlled application and testing of multiple seal coat applications. Rumble strip location, seal coat grade, vehicle type, and speed are also considered. 3) Identify test sections according to the plan. 4) Measure interior noise and vibration for sections before and after seal coat application. Also measure texture with a laser profiler on select sections. 5) Determine how many seal coats result in an unacceptable drop in rumble strip performance.

Research in Progress
Title: NRRA: Materials-Based Methods to Improve Rumble Strip Durability

Organization: Minnesota Department of Transportation
Link: NRRA: Materials-Based Methods to Improve Rumble Strip Durability
Description: The use of centerline rumble strips (CLRS) has been shown to reduce severe head-on crashes on two lane roads by up to 64%. The FHWA has included rumble strips in their new “Proven Safety Countermeasures” initiative, which may result in more widespread use of rumble strips. Through the lens of pavement performance, installing CLRS in asphalt pavements may accelerate deterioration of the pavement at the longitudinal construction joint. Recent research has measured this effect and suggested chip sealing new rumble strips as a preventive measure; however, chip sealing following installation may not be practical or desirable for many reasons. Other materials that have a demonstrable impact on centerline joint durability, without sacrificing the functionality of the rumble strip, have been described, namely Void Reducing Asphalt Membrane (VRAM) and Rapid Penetrating Emulsion (RPE). This project will evaluate the efficacy of these material methods for improving CLRS durability while maintaining safety through the use of full-scale field projects.

Possible members for technical advisory panel

  • Sara Buermann, Wright County
  • Vic Lund, St. Louis County
  • Dave Kramer, Winona County
  • Brian Sorenson, MnDOT
  • Tony Winiecki, Scott County
  • Nate Drews, MnDOT TE
  • Max Moreland, MnDOT TE
  • Randy Newton, St. Paul
  • Mark Vizecky, MnDOT
  • Additional city reps (metro and Greater MN)