OFFICE OF RESEARCH & BEST PRACTICES Michigan Department of Transportation RESEARCH UPDATE MAY 2011 Roundabouts: Making a Safer Interchange ot too long ago, encountering a roundabout on Michigan roadways Nwas a rare occurrence. Not so today, with almost 100 roundabouts constructed and more planned or under way. Increasingly, Michigan is turning to the roundabout as a safer alternative for One of the almost 100 roundabouts constructed in Michigan since 1996, this roundabout is near Bennett some intersections than a traditional signal Woods Elementary School at the intersection of Bennett and Hulett roads in Okemos. light or four-way stop. The roundabout’s circular design, where entering traffic yields to vehicles traveling counterclock- The Michigan Department of wise around a central island, has the Transportation (MDOT) undertook a In This Issue: effect of calming traffic and reducing research project to understand round- congestion while decreasing the number about driver behavior and effective Making a Safer Road of conflict points present in a typical educational countermeasures to This issue of Research Update signalized intersection. improve safety. The result is educa- highlights research projects and new Roundabouts improve safety for tional materials for MDOT and local practices that bolster MDOT’s robust motorists, pedestrians and bicyclists transportation agencies to help spread traffic safety culture and advance its alike, with these intersections tallying the word about roundabouts in goal of making a safer road. fewer and less severe crashes than other Michigan—how to use them and why Roundabouts: Making intersection types. And roundabouts save they are a safer alternative to tradi- a Safer Interchange 1 money by reducing the long-term tional intersections. operational and maintenance costs Education Key to Success Understanding the audience of Clare Roundabout 2 associated with traditional signalized intersections. More Rumble Strips on Rural Highways, An effective educational campaign Fewer Crashes 3 speaks directly to its audience. With Identifying a need this in mind, researchers wanted to Making a Safer Driver 3 While roundabouts are becoming more know more about the public percep- National Trends 4 common in Michigan, they are still rela- tions of roundabouts, and for the Research in Progress 5 tively new to many drivers and residents. drivers having difficulty navigating Program News 6 Gaining public support for roundabouts them, the driving behaviors in need of and helping the traveling public learn correction. Survey results and crash new “rules of the road” is vitally impor- data gave researchers the information tant. they needed to craft an effective message. continued 2 · MDOT ORBP Newsletter · May 2011 Roundabouts: Making a Safer Interchange continued from page 1 Education Key to Success of Clare Roundabout Results of a survey of almost 12,000 road users, mostly from Michigan, in- n 2004, the leaders of Clare, a com- sions with city leaders, and a public dicate that many drivers and residents munity of about 3,000 in central comment period facilitated by MDOT are skeptical of roundabouts during the IMichigan, had a decision to make as Bay Region staff, the community was planning stages, though over time their they prepared to reconstruct the inter- ready to move forward with construc- support for them grows. Exposure to change at U.S. 127 and Mission Road on tion of its first roundabout. roundabouts increases drivers’ comfort the south side of the city. Among the Education continued to play a role and enhances their perceptions of round- four options under consideration: a when the roundabout opened in June about safety. roundabout. 2009, with police opting for education An examination of recent crash data Most community residents had not over tickets for drivers having problems for Michigan roundabouts and crash seen a roundabout and knew little about navigating the roundabout on opening data from previous studies identified them. MDOT Bay Region staff stimu- day. factors commonly associated with lated interest within the community by Local law enforcement has noted roundabout crashes. Among them: providing sketches and information fewer crashes than expected at the • Difficulty understanding yield signs. about the design, operation and safety roundabout, and community feedback • Excessive speed when entering a effects of roundabouts well in advance has been positive. Today, the land- roundabout. of the expected construction date. scaped roundabout, maintained with • Confusion about lane selection and Almost four years before, in fact. city resources and the help of local lane changes in multilane round- After more than a year of public volunteers, serves as a pleasing gateway abouts. meetings, one-on-one educational ses- to Clare’s south side. • Failure to recognize pedestrians and bicyclists. “The Clare roundabout has been an overwhelm- Delivering the message ing success. It has changed the dynamics of the Armed with knowledge of public percep- community.” tions and problematic driver behaviors, researchers developed a collection of educational materials. —Jack Hofweber, Mt. Pleasant Transportation Service Center Manager, MDOT Bay Region • Brochures explain the advantages of roundabouts and offer step-by-step instructions for navigating a round- about. • Animated videos demonstrate the interaction of vehicles, pedestrians and bicyclists in roundabouts in real time. • Posters and PowerPoint presenta- tions describe the operational and safety benefits of roundabouts. These carefully crafted materials provide the traveling public with a variety of ways to learn the roundabout “rules of the road.” They also help MDOT and local transportation agencies This dual roundabout in Brighton is located at Lee and Whitmore Lake roads and Lee Road and advance the message that roundabouts southbound U.S. Highway 23. are a safe and effective alternative to signalized intersections. michigan.gov/roundabouts. Read more 9623_10724_48681_51213_51738---,00. For more information about this research project—“Educating html. The research report will be available Many of the educational materials the Public to Navigate Roundabouts”— online soon at www.michigan.gov/ developed in this project will be in the Research Spotlight available at mdot/0,1607,7-151-9622_11045_24249 available on the MDOT Web site at www. www.michigan.gov/mdot/0,1607,7-151- ---,00.html. www.michigan.gov/mdotresearch · 3 More Rumble Strips on Rural Highways, Fewer Crashes ane departures—where vehicles cross In 2008, MDOT began installing the road. Research results on pavement Lover the centerline or leave the pave- shoulder and centerline rumble strips on condition and bicycle safety will be avail- ment edge—can lead to head-on or run- existing pavements on two- and four-lane able after Phase I concludes in June 2012. off-the-road collisions that are among the rural highways in Michigan. It was the In Phase II, researchers could most severe crashes on rural highways in largest initiative of its kind. A two-part produce a database of before-and-after Michigan. Many of these crashes involve research project—“Impact of Non-Freeway crash data. If significant crash reductions distracted or drowsy drivers. Rumble Strips”—will evaluate this sig- are found, this project could serve as a nificant safety investment. In addition to benchmark for future rumble strip instal- analyzing crash data, researchers will lations in Michigan and other states. examine alternative installation methods, Contact Project Manager Jill Morena preventive maintenance treatments, at [email protected] to learn more impacts on bicyclists, and the impact of about this ongoing project. road noise. Data gathering in Phase I, results in Phase II The first phase of the project began last summer with researchers gathering “before” data on road segments scheduled Centerline rumble strips have been shown to reduce for rumble strip installation. Researchers cross-centerline crashes. used video cameras temporarily mounted An ambitious initiative on road signs to gather field data on driver behavior; MDOT’s pavement management Rumble strips provide an audible warning system video logs provide data on pave- and a physical vibration that warns drivers ment condition. Research will document they are leaving the driving lane. Studies bicycle-related safety concerns and make show that rumble strips reduce lane de- This camera, temporarily mounted on a road sign recommendations on how to address them on a horizontal curve, monitors vehicle position parture crashes, which translates to fewer so motorists and bicycles can safely share injuries and deaths. within the lane of traffic and encroachments into the adjacent lane or shoulder. Making a Safer Driver utting safer drivers on safer roads will continue to reduce traffic fatalities and injuries on Michigan roadways. Chang- Ping the driver behavior that results in crashes is one way to put safer drivers on the road. The practices designed to change driver behavior are called behavioral countermeasures, and they can take the form of new legislation, enhanced enforce- ment, public education, engineering measures or other actions. Countermeasures with potential While all are well intentioned, research has shown that behav- ioral countermeasures vary widely in their effectiveness. What The driving simulator at Central Michigan University’s Center for Driving makes sense in theory may not translate well into practice. And Evaluation, Education & Research