State of The Practice for Shoulder and Center Line Rumble Strip Implementation on Non-Freeway Facilities

APPENDIX B. FOLLOW-UP PHONE INTERVIEWS

Appendix B includes notes taken from follow-up interviews with departments and FHWA’s EFL. Additionally, verbatim department responses to the questionnaire provided in appendix A are included for those States and/or agencies that submitted responses, which include the following:

• ConnDOT.
• FHWA’s EFL.
• LaDOTD.
• MnDOT.
• MDT.
• TxDOT.

Additionally, ConnDOT, FHWA’s EFL, and TxDOT provided direct responses to the appendix A questionnaire. The following sections provide notes from each follow-up interview. The notes include whether the discussion is from the project team or the transportation department.

CONNECTICUT

Follow-up Interview Meeting Notes

Date: Wednesday, March 02, 2016

• The project team asked if a policy review module would help ConnDOT with decisionmaking in addition to providing safety benefits?
  
  
  • ConnDOT was unclear what exactly the tool would contain, so the project team briefly reviewed the tools general concept.
    
    
  • ConnDOT stated that the tool would benefit them and would prefer a standalone tool instead of combining it with anything else. Also, ConnDOT would like to see the tool automate the process of outputting the depth and width, among other dimensions, for the rumble strip.
    
    
• The project team asked what the barriers to implementation have been and how has ConnDOT begun to overcome those barriers? What issues are ConnDOT still wrestling with for SRSs?
  
  
  • ConnDOT has a very active cyclist community.
    
    
  • The barriers are more perceived then actual because CLRSs and SRSs are still in their infancy and rumble strips are a new concept that people are not familiar with in CT.
    
    
• The project team asked if ConnDOT is developing or has developed standards for SRSs or ELRSs on rural two-lane highways.
  
  
  • ConnDOT does not have any official standards yet but they are working on them and making adjustments as they go. They attended a peer exchange and learned about sinusoidal rumble strips and the most current trends. ConnDOT noted that they have adjusted their standards accordingly.
    
    
• The project team asked if there is anything that can help move the SRS/ELRS program forward. Would being able to see what other States do (especially nearby States) help with their decisionmaking?
  
  
  • ConnDOT stated that more funding would always be helpful.
    
    
  • ConnDOT learned in a recent peer exchange about the CLRS and the different types of rumble strips. They discussed these options in-house and have adopted California’s standard for CLRSs.
    
    
• ConnDOT mentioned that the public has perceived that rumble strips help traffic calming. ConnDOT uses them for safety; however, it has helped making rumble strips more accepted within communities.
  
  
• ConnDOT has held a few public meetings regarding rumble strip installation but not a lot of people have attended.
  
  
• ConnDOT’s main struggle has been internal. ConnDOT historically has identified hot spots and has completed projects based on risk factors so it has been a challenging getting the agency to buy-into systemic application.

Interview Questions

General

1. How would you characterize your State’s need for a rumble strip application tool? If a tool was developed that could show/rate the effectiveness (CMF) of installing CLRS on a road it would help the design process as well as allow for a chance to give Cities/Towns more positive evidence to increase buy in.
   
   
2. What would be some preferred characteristics in terms of tool platform and functionality? The tool would need to have adjustments for ADT, Lane Width, etc. to be able to predict the number of expected crashes at a proposed location.
   
   
3. Do you have a policy for using shoulder, edge line, and/or centerline rumble strips on rural, two-lane, two-way roadways? If yes: Centerline rumble strips are new to CT with approximately 40 mi of CLRS installed and 200 more mis set to be installed in 2016. Because they are new, they have only been considered/used as a systemic treatment. CT does not currently have any shoulder rumble strips on two lane roadways.
   
   
4. Do you install on a case by case basis? See Above – a.
   
   
5. On resurfacing projects are rumble strips a consideration/mandatory? No. CLRS are being installed systemically. CT does install Shoulder RS on all Limited Access Highways.
   
   
6. Do you have a program to install rumble strips separate from paving projects? Yes, there have been two RS projects constructed and two more in design since 2014 that have been standalone RS projects.
   
   
7. Under what conditions and circumstances does your State consider rumble strips? Are lower-cost delineation enhancements (e.g., signage and/or striping strategies) always considered first? See Above – a.
   
   
8. Does your State require a certain speed limit, or width of roadway for shoulder rumble strip and/or centerline rumble strip application? CLRS are installed to reduce head-on and sideswipe opposite crashes and are most effective in reducing injuries and fatalities at higher speeds. Due to the nature of the CT State highway system, CT’s minimum speed limit for CLRS is 35 MPH. A major concern with CLRS comes from the bike/ped community who are worried about cars not wishing to cross the CL and encroaching on the shoulder. It is best to install CLRS on roads with a satisfactory shoulder for pedestrian use and in CT we’ve chosen a minimum width of 26' to install CLRS.
   
   
9. Do you have a minimum shoulder width or remaining shoulder width beyond the rumble strip for use of shoulder or edge line rumble strips? If so, would you consider them facilities with lesser shoulders if there was a history of roadway departure crashes? The minimum shoulder width for installing Shoulder RS is 3'. Shoulder RS are only installed on limited access highways.
   
   
10. Does crash history dictate implementation of rumble strips? Is there a specific level of crash history and is there an expected level of crash reduction considered? Due to the infancy of the CT CLRS program, there have only been systemic installations of CLRS and not enough data to develop any CT tailored crash reduction factors. Crash history can certainly dictate that CLRS “should” be installed but there is no policy for it in CT.
    
    
11. Has your State faced issues that had necessitated removal of rumble strips? How have you revamped your policies to continue the rumble strip program? Connecticut previously installed rumble strips at a high-crash location in 1999. These rumble strips were removed within a year due to the large number of noise complaints, and it took until 2014 to begin trying installing CLRS again.

Maintenance/Installation/Cost

1. What are the effects of rumble strip installation on existing roadways especially regarding the pavement deterioration? CT doesn’t have enough data to document any negative effects.
   
   
2. Does your State have a specific policy regarding pavement condition prior to rumble strip installation? If so, how is pavement condition assessed? If pavement condition is not adequate, are any modifications made to allow for installation? No. However, CT has chosen to install CLRS on State roads that have been repaved within 4 years of the installation date. This number comes from the paving management unit which told us that the pavement remains in good condition for up to 4 years. Pavement condition for local roads comes from observation and input from the municipalities. CT has not modified any existing roadways to exclusively accommodate rumble strips.
   
   
3. Does your State allow for raised rumble strips? If so, how does your State consider using raised rumble strips versus milled rumble strips? What is the lifecycle cost, pavement service life and service life of raised rumble strips? No.
   
   
4. Do you have guidelines with rumble strips regarding snow removal, or have weather related issues due to excess rain and hydroplaning? Are rumble strips implemented in areas of bad weather for guidance when visibility is poor? No, CT has no guidelines for snow removal but for that reason does not use raised rumble strips. CLRS have only been installed systematically. CT’s smaller size lends to believe the whole state receives similar weather. It is understood that the CLRS may improve CL delineation, but it has not been causation for installation. CT municipalities have shown interest in CLRS for traffic calming reasons.
   
   
5. Have you experienced debris collecting in the rumble strips? CT has not had any problems with debris.
   
   
6. Do you use fog seal when applying rumble strips? Does the fog seal enhance the rumble strip longevity/performance? Is the fog seal a hindrance during application? Does the fog seal show any positive return results? Is it only an issue when the pavement marking is located directly over top of the rumble strip? CT does not use fog seal.
   
   
7. Do you install rumble strips on open-graded friction course (OGFC) pavements? If so, what are the impacts? N/A. CT uses some Ultra thin bonded HMA.
   
   
8. Are there any pavement types where rumble strips are not used? Is there a difference for new installations versus existing pavement? Previously, chip sealed pavements were avoided for installation of rumble strips. After hearing from a RS peer exchange that chip sealed do not show any extra deterioration from RS, CT has decided to accept chip sealed roads in future projects.
   
   
9. What is your centerline rumble strip policy for passing zones? Has safety been analyzed in regards to centerline rumble strips for passing zones? CT does not install CLRS in passing zones, with the main reason being trying to limit any noise created by vehicles hitting CLRS legally/purposefully (as opposed to accidentally hitting them in a non-passing zone)
   
   
10. Do you have any policies in place for gaps in the rumble strip pattern other than for bicyclists? For example, do you have gaps for passing zones, at driveways, intersections
    or on the inside of horizontal curves? CT does not install CLRS in passing zones, where there is a break in the centerline or on bridge decks.

Bicyclist Accommodations

1. How does your State accommodate bicyclists? Are bicyclists considered for every shoulder rumble strip installation or only when bicyclists are expected? Do you have separate standards for bicycle locations and non-bicycle locations? The only consideration for bicycle activity is to install CLRS on roadways 26' wide or more. CT has not installed shoulder rumble strips, and therefore bike gaps, on SR’s.
   
   
2. Does your State provide gaps for bicyclists? If so, what pattern do you use (e.g., 12 ft every 60 ft)? N/A
   
   
3. Do you have a minimum shoulder width specified for bicyclists? Does this differ from the required minimum shoulder width if bicyclists are not expected? Minimum shoulder width for shoulder rumble strips on Limited Access Highways is 3'. No bicycle activity on LAH.
   
   
4. How do you address bicycle outreach? Are there any outspoken bicyclist or motorcycle unions that have input into your policies? During design, a bicycle and pedestrian assessment form is submitted to the Office of Intermodal Planning for their consideration. A letter is sent to all chief elected officials to explain the project and allow them to request a public meeting. There is no CLRS policy so there has not been any feedback from the community.
   
   
5. Do you consider alternative designs for areas with potential bicyclist concerns? For example, would you consider a shorter length, shorter depth, or an alternative pattern (e.g., sinusoidal design)? Connecticut does have a complete streets policy that does have designers consider bicyclists everywhere. CT has one standard application for CLRS.

Noise Policy

1. Does your State struggle with noise complaints, despite outreach prior to installation? If so, how do you address these complaints? What public outreach did you perform before the installation of rumble strips? Only a few complaints thus far. These noise complaints were handled by a staff member who explained the safety benefits of rumble strips. A letter was sent to the chief elected official as well as the local traffic authority informing them of the project and allowing a chance for the municipality to request a public hearing/informational meeting.
   
   
2. Does your State have distance criteria from residences? If so, is the criteria based on expected noise level or is it a pre-defined distance? There is no defined distance from house to road. Design takes into consideration proximity and density of residences along candidate locations.
   
   
3. In regards to hamlets (small villages along a rural corridor), what are your equivalent policies/procedures regarding installation adjacent to residential areas? N/A
   
   
4. If nearby noise is within an acceptable limit (specified in question 2), how do you address the public due to the different type of noise that the rumble strips produce? In Connecticut’s noise analysis of our own CLRS, it was found that during busy traffic periods, the rumble strips produced a noise with a db level similar to the ambient traffic. The issue with our complaints have been at quieter hours when the rumble strips are hit and produced a noise higher than the ambient level, and also the pitch of the sound was different. Our strategy has been to try and educate the public on the safety benefits of CLRS, and that helps offset concerns about noise.

Approval/Buy-In

1. What outreach has your agency conducted prior to installation? Who has the outreach targeted (e.g., motorcycle groups, bicycle croups, neighborhoods)? A letter is sent to the chief elected official and LTA of the city/town and a request is made to concur with the project or request a public hearing/informational meeting.
   
   
2. If a Public meeting is requested, a press release is circulated in a mainstream newspaper to inform the public of the meeting. At the meeting a presentation is given and followed up by a Q&A. We have not had any outreach to any other groups such as motorcycle or bicycle groups.
   
   
3. What methods have you used to gain upper management/elected officials approval/buy-in? Install CLRS on both State and locally owned roads, under State projects so municipalities do not have to pay. Describe the safety benefits of CLRS and offer help to choose quality candidate locations. CLRS fit under the strategies of Connecticut’s Strategic Highway Safety Plan, which has helped gain internal support for their installation.
   
   
4. What type of material do you use to gain public acceptance and perceptions regarding rumble strips? Flyers, informative videos, DOT Web site dedicated to rumble strip information and installation? The State is preparing these rumble strip projects to install them on State and Local roads at no cost to the municipalities. There is a link on the CT DOT Web site which brings you to a brochure on the benefits of CLRS.
   
   
5. How do you sell rumble strips in residential areas with documented crash histories? Our efforts to sell rumble strips will center around their safety benefits.

FHWA’S EFL

Follow-up Interview Meeting Notes

Date: Monday, February 29, 2016

• EFL provided a brief overview of the role of EFL and what they do. EFL’s role includes the following:
  
  
  • Provides technical assistance to Federal agencies.
    
    
  • Provides planning, engineering, and construction (including road safety) but does not own any roadways.
    
    
  • Noted that wildlife and environmental issues are typically a large concern; noise is a huge concern.
    
    
• The project team asked a follow-up to EFL’s comment in the written interview questions, regarding using signage, striping etc. before using rumble strips. The discussion included the following:
  
  
  • The EFL noted that around curves they suggest chevron signage or even
    pavement markings.
    
    
    • A lot of roads do not have edge lines or signage because the partners (customers) do not like the visual clutter or how the stripes effect the wildlife. When asked if signage has been effective, EFL noted that no-one has complained that signage has not been working.
      
      
    • The EFL installed rumble strips in the Great Smoky Mountain National Park but they were installed improperly, so there has been some push back regarding rumble strips.
      
      
    • EFL has a new project coming in to hopefully fix the rumble strips.
      
      
  • The project team asked if there was any buy-ins or approvals needed when the Smoky rumble strips were installed?
    
    
  • The EFL responded that they do not believe so.
    
    
• The project team asked the EFL what they would like to see in a rumble strip tool and if they would prefer it to be stand alone or in another tool? The EFL responded that it needs to be user friendly. If it is too complicated their engineers will not even open it. They recently received a striping tool that was in excel and it was easy to use and generally accepted with the engineers. The EFL made several additional notes, including the following:
  
  
  • They would like to see an alert for minimum lane width and shoulder widths. Also, they would like the tool to specify how to apply rumble strips in different situations.
    
    
  • They mentioned a picture from a peer review exchange with a rumble strip located right next to a rock wall and noted how this might not be very useful since the
    driver might hit the rock anyways. They would like to see a tool that would address different situations (e.g., alerts for narrow lane width, narrow shoulder width, or narrow roadside).
    
    
  • They noted that the tool could recommend alternatives to rumble strips.
    
    
  • They noted that from the Peer Exchange most States are providing rumble strips everywhere; therefore, the tool may not help these States, but it could help States that are struggling.
    
    
  • They also noted a lack of consistency between customers; there are hundreds of people (e.g., park managers) to say no and it is difficult to sell the effectiveness.
    
    
• The project team asked if EFL has proposed rumble strips in other areas. The following discussion ensued:
  
  
  • The EFL has proposed rumble strips in other areas and received push back. But they receive push back for everything from edge line striping to signage and rumble strips. They usual justify their decision by crashes.
    
    
  • The project team asked if having figures and results showing the usefulness of rumble strips would be helpful?
    
    
  • The EFL noted that yes it would be helpful in defending their safety suggestions.
    
    
  • The project team asked if there is currently a threshold for percent crashes or other circumstances that makes installing rumble strips, edge line and signage easier to justify?
    
    
  • The EFL noted that there is no threshold.
    
    
• The project team asked if the EFL has any standards or details for bicycle use and rumble strips. The EFL responded that they do not but would need to look into this if they installed rumble strips. They noted that many professional bicyclers go very fast on EFL roadways.
  
  
• The project team asked if the EFL has any approvals or buy-ins when suggesting rumble strips. The EFL responded with No. Projects are approved unit by unit, so each situation is approved by different individuals.
  
  
• The EFL noted that they are currently looking into systemic installation of rumble strips. There has been positive change in opinions regarding rumble strips recently. Also, the unit manager makes the ultimate decision regarding which application to use on each project.
  
  
• The project team asked if the EFL has any standards or details regarding rumble strips? When the EFL was involved in the peer exchange they noticed a lot of states are just using systemic installation of rumble strips. This halted the current standards that Central Federal Lands was working on. They do not have finalized plans but they do have a word document that EFL will send to the project team.

Interview Questions

1. If FHWA develops a rumble strip application tool, will you use it? Yes. Do you see the usefulness of the tool in the near-term or potential tool requirements in the future? Yes. Would you have preferences as to what you would like in the tool platform and/or its functionality? I am not sure what platform you are able to develop. At least an Excel type file would work if that is what you are thinking. Something user friendly and not too laborious so engineers here can use it.
   
   
2. When does a State consider rumble strips? Does a state try signage, striping, and other enhanced delineation before considering rumble strips if the short-term improvements don’t provide the intended reduction in crashes? In the case of Federal lands, yes, we try signage, striping and other delineation before proposing rumble strips since our partners (customers) are very sensitive to the noise rumble strips would create to the environment.

Maintenance/Installation/Cost

1. On resurfacing projects are rumble strips a consideration/mandatory? No.

LOUISIANA

Follow-up Interview Meeting Notes

Date: Tuesday, March 8, 2016

• The LaDOTD began by explaining that they have a complete streets policy for non-motorized vehicles that focuses on pedestrians along with a safety coalition. These groups have to report progress to the legislature. They also have an advisory council (12–13 people that meet quarterly), which includes FHWA, upper management, senior citizen advocates, and bicycle groups with an additional internal steering committee. LaDOTD has a lot of groups that advise and review plans before rumbles are even installed.
  
  
• The project team asked the LaDOTD to characterize their need for a rumble strip application tool. The LaDOTD responded by stating that they already have a standing policy with no push back so they would have no use for the tool. However, they may consider using it depending on tool information and interface.
  
  
  • The project team asked the LaDOTD for their thresholds for rumble strips installation. The LaDOTD responded with the following criteria: 50 mi/h threshold.
    
    
  • CLRS program requires a minimum of 22 ft of pavement that isn’t older than 10 years.
    
    
  • 10 ft every 40 ft on everything except limited access roadways.
    
    
  • 4-ft minimum shoulder for shoulder rumble strips and occasionally less than 4 ft.
    
    
  • For SRS on greater than 22-ft paved roadway.
    
    
  • For CLRS and ELRS on greater than 28-ft paved roadway.
    
    
  • Milled rumble strips—Raised markings on bridges and approach slabs because LaDOTD does not allow milling on bridges.
    
    
  • Concrete—Can form them as long as they are the same as the milled rumble strips.
    
    
• The project team asked if LaDOTD had faced any issues with rumble strips. The LaDOTD indicated no push back for CLRS or ELRS but rumble strips are not installed in residential areas.
  
  
• The project team asked if LaDOTD noticed any effects of rumble strip installation on existing roadways, especially regarding the pavement deterioration. The LaDOTD responded that they have not noticed any deterioration at rumble strips. They currently have a pilot program with fog seal. The LaDOTD believed Georgia was having issues with deterioration.

MINNESOTA

Follow-up Interview Meeting Notes

Date: Friday, March 04, 2016

• MnDOT noted that they have the following rumble strip guidelines:
  
  
  • If a project is being resurfaced they install rumble strips.
    
    
  • If the shoulder is greater than 4 ft, they install rumble strips—2 inches away from joint.
    
    
  • If the shoulder is less than 4 ft, they install the rumble strips as far as possible on the edge of the pavement.
    
    
  • Motorcycle riders have been consulted and do not mind the rumble strips.
    
    
  • Have not researched pavement issues.
    
    
  • Rumble strips are installed on a case-by-case basis.
    
    
• MnDOT noted that early on they installed a lot of ELRSs. Because people hug the edge line and there have been a lot of noise issues, so MnDOT moved towards CLRSs instead. MnDOT maintenance has concerns with centerline joint degredation.
  
  
• MnDOT noted that they have a Non-Motorized Advisor Committee that assists with the design and comments of where rumble strips are installed.
  
  
• In regards to old roadways pavements, MnDOT noted the following:
  
  
  • They do install rumble strips.
    
    
  • There has been push back in regards to installing rumble strips in old pavements.
    
    
  • Installations have mostly taken place on county roads.
    
    
• MnDOT noted the following challenges with buy-in:
  
  
  • They struggle with installing rumble strips systemically.
    
    
  • In the past they have had to remove CLRSs due to noise issues.
    
    
  • Some districts in MN are not on board at all with rumble strips and do not install any.
    
    
  • They have had some legislative and public push back, which made them change their practices and with ultimately led them to sinusoidal rumble strips. Sinusoidal rumbles are being considered in areas of noise concerns (A technical memo will be written from MnDOT regarding their findings this summer). MnDOT is looking at another design, calling it the MN mumble strip. MnDOT contractors have a machine that can change and adapt to their changes to rumble strip installation.
    
    
• MnDOT is conducting a study currently regarding optimization study for rumble strips. MnDOT provided the following information regarding the study:
  
  
  • South Dakota, North Dakota, and Washington have been in contact and are waiting on MnDOT results.
    
    
  • The have had a small wrinkle in the research regarding motorcyclists, which they are currently working through.
    
    
  • They are meeting next week to discuss the design.
    
    
  • The study should be complete March/April.
    
    
  • The interim design will be applied along 200 mi or roadway in MN and then reviewed.
    
    
• Regarding the development of the FHWA tool, MnDOT provided the following feedback:
  
  
  • MnDOT feels they have no use for the tool.
    
    
  • The public does not understand just by statistics or crashes why rumble strips should be installed. They need something in the tool to help change the opinions of the public regarding rumble strips.
    
    
  • Research should be conducted looking at whether rumble strips increase the degradation of the pavement.
    
    
  • They do not know where rumble strips are located within the state. They need a database of where rumble strips are located.
    
    
  • They would like to see safety results in regards to narrower rumble strip widths.
    
    
  • They would like to see research on rumble strips on concrete pavement.
    
    
• Sinusoidal rumble strips are only currently used on CLRSs of MnDOT. Districts are considering using it for SRSs. They are looking at installing recessed reflective pavement markers in with sinusoidal rumble strips.
  
  
• MnDOT is working on a research study regarding rumble strips. The results indicate the following:
  
  
  • CLRSs and SRSs should be installed on all roads with 4,700 ADT and above. The research was based on fatal crashes.
    
    
  • Crashes at passing areas were generally not due to cars passing.

MONTANA

Follow-up Interview Meeting Notes

Date: Monday, February 29, 2016

• The project team asked if there were any criteria to not use rumble strips. MDT indicated the following:
  
  
  • There is no AADT criteria.
    
    
  • Speeds less than 45 mi/h are excluded from installation (used as a surrogate for urbanization).
    
    
  • If the shoulder is greater than 4 ft wide, MDT only avoids for noise concerns.
    
    
  • If there are several houses within 600 ft of the rumble strips, they will likely choose not to install, if there is only one receptor or house the will go ahead and put them in. However, MDT noted that there are no definitive criteria.
    
    
  • MDT noted that if there is noted bicycle usage, crash data justify rumble strips, and the shoulder width is less than four ft that is when they will get together and use a committee to come to a consensus about that particular installation.
    
    
  • MDT noted that they will use signing to address crashes as necessary.
    
    
• The project team asked if MDT receives feedback or buy-in from bicycle groups.
  
  
  • MDT noted that they sent out modified guidance and received pushback on the language. MDT engaged the bicycle community to receive feedback on things such as designers should be aware that there is a “goal to have 4 ft clear.”
    
    
  • MDT modified the design to allow for bicycles and use quality control to try to ensure that 4 ft is maintained. They are stressing to the construction folks the importance for quality in this case.
    
    
  • MDT identifies high priority bicycle routes by engaging the pedestrian and bicycle coordinator who interacts with the pedestrian and bicycle groups to determine the protected routes. Additionally, they will utilize tools such as bicycle heat maps to identify high-usage bicycle routes.
    
    
• MDT noted that they struggle to utilize innovative treatments due to difficulties for contractors. For example, they have not tried anything similar to Minnesota’s mumble strips due to a lack of information on whether the contractor’s need to modify existing equipment or buy new equipment to implement them. MDT is waiting for research to show the effectiveness before trying out innovative treatments.
  
  
• The project team asked if the ELRS usage on highways with 4-ft shoulders came from the bicycle community.
  
  
  • MDT noted that this is something that they have been researching because of perceived maintenance issues. Rather than using rumble strips on the outside edge of the pavement, they have decided to try narrowing the lane by 6 inches to create a rumble stripe to make the shoulder as wide as possible. The goal is to provide at least a 4-ft bicycle lane.
    
    
• The project team provided an overview of the proposed FHWA tool and asked for MDT’s reaction and interest in such a tool. MDT provided the following reactions:
  
  
  • It would be difficult to use anything other than their standard drawings.
    
    
  • Guidance drives practice.
    
    
  • Once they get over the initial hurdle, it is easier to implement rumble strips.
    
    
  • They borrowed North Dakota’s CLRS design and have installed about 110 mi of CLRSs. They have noticed a different sound between their SRSs/ELRSs and CLRSs. They like the sound difference because it alerts a driver to which side they are striking the rumble strips.
    
    
  • MDT noted that the struggle is that they only provided rumble strips on roadways with shoulder four ft or wider, but over 60 percent of crashes on in areas with less than 4-ft shoulders.
    
    
  • They would be interested in a tool that could perform some sort of analysis to look at trade-offs in known bicycle use in crash data.
    
    

TEXAS

Follow-up Interview Meeting Notes

Date: Friday, February 26, 2016

• The project team asked what tools TXDOT currently uses.
  
  
• TxDOT noted that they are developing an application for collecting information on rumble strips. The current issue is that they do not know where they have rumble strips installed. TxDOT noted that they are ahead of the curve for developing a systematic approach; however, the biggest challenge is determining where they already are within the database of roads that qualify or systemic-based installation. They also suggested that the tool would probably be most useful inside of more popular tools.
  
  
• TxDOT noted that the big news is that they are now looking into a systematic approach to rumble strip safety since they are looked at as being very favorably within the district.
  
  
  • They are planning installations for two-lane rural highways, with posted speed limit greater than 45 mph, adequate widths, and 2-ft shoulders.
    
    
  • Commonly use the following three types of rumble strips:
    
    
    • Milled.
      
      
    • Profiled thermoplastic.
      
      
    • Raised ceramic buttons.
      
      
  • Seal coats are their kryptonite—they often do not have adequate depth and profiled thermoplastic pavement markings cannot be placed until 4 to 6 months after seal
    coat application.
    
    
• TxDOT noted that they are in favor of rumble strips. They follow FHWA guidance on placement and gaps—the next update may be more specific.
  
  
  • They are currently inventorying designated bicycle routes to build a bikeway map that is logical, and add to as needed. Once this map is constructed the Bicycle and Pedestrian Coordinator would review the bicycle paths.
    
    
  • Designated bicycle routes are required to have a minimum 4-ft shoulder.
    
    
• TxDOT noted that the biggest challenge is knowing where they are right, identifying where they should be, and then having the districts identify if they have them or a project is planned. Gaps will identify where they are not. The Bicycle and Pedestrian Coordinator will identify which are bicycle routes. Additionally, they noted the following:
  
  
  • Districts are seeing a shift in how bicycle routes are designated.
    
    
  • Additionally, there is less pushback now.
    
    
• TxDOT noted that rumble strips are allowed in urban areas if there is a crash problem. Additionally, they noted the following:
  
  
  • They do not typically have a noise problem because of the 45 mi/hr cut-off.
    
    
  • They get a few complaints and they try to sell the effectiveness.
    
    
  • They have had to remove rumble strips due to noise complaints, but it has had no long-term impacts on their ability to install them.
    
    
  • They look at each installation on a case by case basis but the 45 mi/hr is the main threshold. Rural versus urban designation is a secondary threshold. They leave it up to districts to obtain the feel for the designation.
    
    
• TxDOT noted that they have talked to motorcycle groups but do not go talk to homeowners to sell before installation. Future work can be tracked on project tracker. The motorcyclists are heavily in favor of rumble strips. They also noted that ceramic buttons are very dangerous for bicycles and motorcycles. They are the least type used and are not recommended on bike routes.
  
  
• TxDOT mentioned that they have a few bicycle groups that are involved on projects as an advisory committee. Anything bike related they bring it up for their input. They have a research project looking at widening roadways due to bicycle use.
  
  
• TxDOT mentioned that the Atlanta district also uses bars (they will sending the standard drawings), which are best for installations that will eventually be covered by a seal coat. However, they do not do well with snow plows. TxDOT mentioned that only use one seal coat on the preformed bars and retain the audible noise. Two coats removes the audible noise from the preformed rumble strips.
  
  
• TxDOT noted that they look at shoulder widths for profiled pavement markings versus milled edge line rumble stripes. Additionally, TxDOT noted that in addition to the systemic approach, crash history will dictate the use of rumble strips on roadways with shoulders less than 2 ft in width. Safety Improvement Index is used for crash history-based installation.
  
  
• TxDOT explained that they install rumble strips in the locations with the highest Safety Improvement (SI) benefit. Most of the rumble strip projects have the highest SI cost benefits so they rank and complete rumble strip projects based on the highest SI. It was stated that rumble strips reduced fatal crashes by approximately 50 percent. It was not determined what type of crashes.
  
  
• TxDOT noted that they would be interested in looking at the tool but TXDOT might be ahead of the tool in policy and execution. TxDOT also noted that that they would prefer the tool be added onto an existing tool.

Interview Questions

1. How would you characterize your State’s need for a rumble strip application tool? Texas has a rumble strip policy which requires edge line rumble strips on all rural 4 lane or more divided highways. That policy has been in place since 1999. Texas is in the process of developing a Systematic Rumble Strip policy for undivided highways. Texas is in agreement that a rumble strip application tool would be useful, but Texas is working to incorporate rumble strips as a standard on Texas highways.
   
   
2. What would be some preferred characteristics in terms of tool platform and functionality? Mapping capabilities.
   
   
3. Do you have a policy for using shoulder, edge line, and/or centerline rumble strips on rural, two-lane, two-way roadways? Rumble strips are required for 4 lane or more divided rural highways with a speed limit greater than 45 MPH. For all other highways, rumble strips are currently not required. The Systematic Rumble Strip study is recommending edge line and centerline rumble strips for rural highways with speed limits greater than 45 mi/h and at least 26 ft of paved surface width (2 or more ft of shoulder width). If yes:
   
   
   1. Do you install on a case by case basis? Currently rumble strips are installed on a case by case basis on rural, two-lane, two-way roadways.
      
      
   2. On resurfacing projects are rumble strips a consideration/mandatory? No, rumble strips are not considered mandatory on resurfacing projects.
      
      
   3. Do you have a program to install rumble strips separate from paving projects? Yes, the Texas Highway Safety Improvement Program (HSIP) programs rumble strip projects based upon a benefit-cost analysis.
      
      
   4. Under what conditions and circumstances does your State consider rumble strips? Rumble strips are required for 4 lane or more divided rural highways with a speed limit greater than 45 mi/h. Rumble strips are considered for rural highways with at least 26 ft of paved surface width (2 or more ft of shoulder width). Are lower-cost delineation enhancements (e.g., signage and/or striping strategies) always considered first? Rumble strips are typically one of the first considerations due to their high benefit‑cost ratios.
      
      
4. Does your state require a certain speed limit, or width of roadway for shoulder rumble strip and/or centerline rumble strip application? The speed requirement for rumble strips is for highways with speed limits greater than 45 mi/h.
   
   
5. Do you have a minimum shoulder width or remaining shoulder width beyond the rumble strip for use of shoulder or edge line rumble strips? If so, would you consider them facilities with lesser shoulders if there was a history of roadway departure crashes? Paved surfaces of 26 ft or greater (2 ft of shoulder width) are preferred to allow drivers need about 15 to 18 inches to recover from a roadway departure but Texas will consider locations with narrower shoulders, if the site has a history of run off the road crashes.
   
   
6. Does crash history dictate implementation of rumble strips? Is there a specific level of crash history and is there an expected level of crash reduction considered? Rumble strips are required for 4 lane or more divided rural highways with a speed limit greater than 45 mi/h. Currently rumble strips on undivided highways are installed based upon a benefit-cost analysis of the crash history at that location. The higher the benefit-cost ratio; the more likely they will be installed.
   
   
7. Has your State faced issues that had necessitated removal of rumble strips? How have you revamped your policies to continue the rumble strip program? The policy of installing rumble strips in rural areas minimizes the need to remove rumble strips. Texas has removed rumble strips due to noise complaints but that is a very rare circumstance.
   
   

Maintenance/Installation/Cost

1. What are the effects of rumble strip installation on existing roadways especially regarding the pavement deterioration? The Texas Rumble Strip Standard sheets require a pavement depth of 2 inches to install milled rumble strips.
   
   
2. Does our State have a specific policy regarding pavement condition prior to rumble strip installation? The Texas Rumble Strip Standard sheets require a pavement depth of 2 inches to install milled rumble strips. If so, how is pavement condition assessed? The pavement condition is assessed by the pavement experts in the TxDOT District offices. If pavement condition is not adequate, are any modifications made to allow for installation? If the pavement condition will not support milled rumble strips, profile rumble strips or raised rumble strips can be installed.
   
   
3. Does your State allow for raised rumble strips? Yes If so, how does your State consider using raised rumble strips versus milled rumble strips? Milled rumble strips are preferred, but raised rumble strips (ceramic buttons) are allowed. Raised rumble strips are not widely used throughout the state; milled rumble strips and profile rumble strips are more common. The type of rumble strip is determined by pavement depth and district preference. What is the lifecycle cost, pavement service life and service life of raised rumble strips? Raised rumble strips have a 2 year service life whereas profile pavement markings have a 5 year service life, and milled rumble strips have a 10 year service life.
   
   
4. Do you have guidelines with rumble strips regarding snow removal, or have weather related issues due to excess rain and hydroplaning? No, there are no guidelines for snow removal. Currently the Amarillo district is testing raised rumble strips and profile rumble strips to determine the effect by snow plows. There have been no reports of hydroplaning incidents due to rumble strips to our knowledge. Are rumble strips implemented in areas of bad weather for guidance when visibility is poor? Rumble strips are not used for visibility purposes, but may have a positive impact for visibility.
   
   
5. Have you experienced debris collecting in the rumble strips? Nothing has been brought to our attention.
   
   
6. Do you use fog seal when applying rumble strips? A few TxDOT Districts use fog seal when applying rumble strips, but the majority of districts do not use fog seal. Does the fog seal enhance the rumble strip longevity/performance? No studies to verify enhanced longevity or performance. Is the fog seal a hindrance during application? Not aware of any hindrances. Does the fog seal show any positive return results? No studies to verify positive results. Is it only an issue when the pavement marking is located directly over top of the rumble strip? N/A.
   
   
7. Do you install rumble strips on open-graded friction course (OGFC) pavements? Yes If so, what are the impacts? Seal coat highways typically do not have the minimum pavement thickness required to install a milled depression (pavement thickness of 2 inches or more is required), and the installation of profile pavement markings and traffic buttons is not recommended for at least six months to a year after the seal coat is installed so that the grade 3 or 4 rocks have adequate time for embedment.
   
   
8. Are there any pavement types where rumble strips are not used? No Is there a difference for new installations versus existing pavement? The installation of profile pavement markings and traffic buttons is not recommended for at least six months to a year after a seal coat is installed so that the grade 3 or 4 rocks have adequate time for embedment.
   
   
9. What is your centerline rumble strip policy for passing zones? Continue centerline rumble strip through the passing zone. Has safety been analyzed in regards to centerline rumble strips for passing zones? No specific study related to passing zones has been conducted.
   
   
10. Do you have any policies in place for gaps in the rumble strip pattern other than for bicyclists? For example, do you have gaps for passing zones, at driveways, intersections or on the inside of horizontal curves? Yes, gaps are used at intersections, driveways, entrance ramps, exit ramps, and turnarounds. For milled in rumble strips gaps are used on bridges and overpasses. Profile rumble strips and raised rumble strips do not require gaps at bridges and overpasses.
    
    

Bicycle Accommodations

1. How does your State accommodate bicyclists? On roadways with high bicycle activity, consideration is given before the installation of edge line rumble strips. Things considered include size of rumble strips, rumble strip material and location of rumble strips on the shoulder. If the designer determines that gaps are needed in the rumble strips due to bicycle use of the road, the requirement shown in FHWA Technical Advisory T5040.39, or latest version detail of the spacing are included in the plans. Are bicyclists considered for every shoulder rumble strip installation or only when bicyclists are expected? Only on roadways with high bicycle activity. Do you have separate standards for bicycle locations and non-bicycle locations? No. The requirement shown in FHWA Technical Advisory T5040.39, or latest version detail of the spacing are used.
   
   
2. Does your State provide gaps for bicyclists? Yes. If so, what pattern do you use (e.g., 12 ft every 60 ft)? A typical pattern is gaps of 10 to 12 ft between groups of the milled-in elements at 40 to 60 ft.
   
   
3. Do you have a minimum shoulder width specified for bicyclists? In order to be considered a bike lane, 4 ft of shoulder width is needed, although a bicycle may use the main lane of a road. Does this differ from the required minimum shoulder width if bicyclists are not expected? There are no extra requirements for rumble strip application for a road that expects to have bicycles other than the gaps in edge line rumble strips described above.
   
   
4. How do you address bicycle outreach? Texas has a Bicycle Advisory Committee (BAC). By involving representatives of the public, including bicyclists and other interested parties, Texas helps ensure effective communication with the bicycle community. The bicyclist's perspective is considered in the development of departmental policies affecting bicycle use, including the design, construction and maintenance of highways. Are there any outspoken bicyclist or motorcycle unions that have input into your policies? See above for bicyclists. Texas also has a Motorcycle Safety Coalition. The bicycle and motorcycle groups both have input into Texas policies.
   
   
5. Do you consider alternative designs for areas with potential bicyclist concerns? Yes. For example, would you consider a shorter length, shorter depth, or an alternative pattern (e.g., sinusoidal design)? Things considered include size of rumble strips, rumble strip material and location of rumble strips on the shoulder.
   
   

Noise Policy

1. Does your State struggle with noise complaints, despite outreach prior to installation? No If so, how do you address these complaints? Complaints are minimal. Consideration is given to noise levels when edge line rumble strips are installed near residential areas, schools, churches, etc. A minimum of ³/₈ inches depth of milled rumble strip may be considered in these areas. What public outreach did you perform before the installation of rumble strips? None
   
   
2. Does your State have distance criteria from residences? No If so, is the criteria based on expected noise level or is it a pre-defined distance? Rumble strips are recommended in rural areas. Rural areas are defined as areas with populations less than 5,000 people. There are no pre-defined distances or noise levels that are required. Installation is looked at on a case by case basis.
   
   
3. In regards to hamlets (small villages along a rural corridor), what are your equivalent policies/procedures regarding installation adjacent to residential areas? Consideration is given to noise levels when edge line rumble strips are installed near residential areas, schools, churches, etc. A minimum of ³/₈ inches depth of milled rumble strip may be considered in these areas.
   
   
4. If nearby noise is within an acceptable limit (specified in question 2), how do you address the public due to the different type of noise that the rumble strips produce? N/A
   
   

Approval/Buy-In

1. What outreach has your agency conducted prior to installation? Not aware of any outreach at locations that rumble strips are installed. Texas reaches out to bicycle and motorcycle groups concerning the rumble strip policies. Who has the outreach targeted (e.g., motorcycle groups, bicycle croups, neighborhoods)? Bicycle Advisory Committee and Motorcycle Safety Coalition
   
   
2. What methods have you used to gain upper management/elected officials approval/buy-in? Demonstrated the historical crash reduction factor for rumble strip installations.
   
   
3. What type of material do you use to gain public acceptance and perceptions regarding rumble strips? None Flyers, informative videos, DOT Web site dedicated to rumble strip information and installation? None
   
   
4. How do you sell rumble strips in residential areas with documented crash histories? Other types of rumble strips are considered to minimize noise complaints.