USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Public Roads - May/June 2017

May/June 2017
Issue No:
Vol. 80 No. 6
Publication Number:
Table of Contents

Slamming on The Brakes on A Mounting Problem

by Guan Xu, Rebecca Crowe, Gabriel Rousseau, and Lisa Kinner Bedsole

With motorcycle fatalities on the rise, applying optimal countermeasures can make a dent in these increasingly grim statistics.

Motorcyclists are at a greater risk for injuries and fatalities than many other roadway users because they do not have the protection of an automobile’s frame to lessen crash impacts.

Ten years ago, motorcycles were involved in 1 out of every 10 vehicle fatalities. By 2014, despite making up only 3 percent of registered motor vehicles, motorcycles were involved in 1 out of 7 fatal crashes. Although total traffic-related deaths have trended downward until recently, the number of motorcycle-related fatalities has increased significantly, from 2,116 in 1997 to 4,576 in 2005 and then to 4,976 in 2015, an overall increase of 174 percent.


Many factors contribute to the rise in motorcycle-related fatalities, including roadway geometry, statutory and advisory speeds, and the behavioral characteristics of motorcyclists. Established engineering practices may not adequately consider the unique characteristics of motorcycles, as is the case with advisory speeds at horizontal curves, where the conventional approach to setting speeds was developed with the automobile in mind. Furthermore, roadside and median barriers have been largely designed to contain and redirect passenger vehicles. Similar barriers that could reduce the severity of motorcycle impacts have not been tested for use in the United States, and FHWA does not advocate their use at this time, although barrier modifications have been tested and installed in Europe to reduce the severity of motorcycle impacts with guardrails.

Motorcyclists and their behaviors also must be taken into account. In 2006, the average age of motorcycle riders killed in motor vehicle traffic crashes was 39, and in 2015 the average was 42. These data suggest that age does not always translate to experience or ability. Impaired riding is also a significant factor in fatal motorcycle crashes: 42 percent of motorcycle riders who died in single-vehicle crashes in 2015 were alcohol impaired.

A number of approaches are needed to help put the brakes on these statistics. The first step is identifying the road segments where motorcycle crashes are overrepresented and applying appropriate countermeasures where they are needed most. Motorcycle road safety audits (RSAs) offer an effective and methodical approach to identifying and applying these countermeasures.

Conducting a Motorcycle RSA

The factors that affect the safety of motorcyclists often differ from those that affect the safety of automobile users. Selecting the right set of solutions to address overrepresented motorcycle crashes on a specific road segment is therefore challenging. Many different types of safety strategies and countermeasures can reduce crashes and fatalities among motorcyclists when applied appropriately.


A motorcycle RSA can help practitioners identify the most appropriate countermeasures for specific locations that will lead to crash reductions. This safety assessment is specifically tailored to address motorcycle safety concerns, differing slightly from the standard RSA, which addresses safety issues that affect a broader set of road users.

An RSA is the formal safety performance examination of an existing or future road or intersection by an independent, multidisciplinary team. The audit team qualitatively estimates and reports on potential road safety issues and identifies opportunities for improvements in safety for all road users. A motorcycle RSA generally follows the same step-by-step procedure as a standard RSA.

RSA teams typically consist of persons with expertise in road safety, traffic operations, road design, and law enforcement. It is advisable for the law enforcement officers selected to serve on the RSA team to have riding experience, or to be actively conducting motorcycle patrols. RSA organizers also should select team members with expertise critical to understanding the conditions affecting motorcyclists, such as representatives of licensing authorities, motorcycle safety clubs, and other groups and organizations with an interest in motorcycle safety.

Jim Compton, a motorcycle safety instructor for the Motorcycle Safety Foundation, was on the RSA team that reviewed North Carolina (NC) Route 28 (known as a “Tail of the Dragon” for its extensive horizontal and vertical curvature) as well as NC–43, both of which are in Graham County, NC, near the Tennessee border. “We had an extremely diverse team that involved engineers, law enforcement, and safety staff,” he says. “As a rider with more than 30 years of experience, and a Motorcycle Safety Foundation instructor since 1999, I was pleased to explain how a motorcycle has to maneuver and react to different highway designs.”

Once selected, the RSA team reviews and discusses crash data, as well as the anecdotal experiences of motorcyclists from local clubs and organizations, during the startup meeting. At that meeting, those familiar with riding describe and interpret the data to help determine factors contributing to crashes and their potential effect. These individuals provide details concerning critical conditions or locations that other team members may not be aware of.

An RSA should be conducted on existing facilities based on crash frequency. The RSA team should review the critical conditions in the field at those locations. Furthermore, team members who are licensed motorcyclists should ride the locations under investigation and convey their knowledge and experience to the RSA team.

Once the field review is complete, the team conducts an RSA workshop in which they compare the experiences and observations of the riders to the field condition review. Based on this analysis, the RSA team identifies any conditions critical to the safety of motorcyclists and suggests measures that may reduce the risks.

In 2016, the Federal Highway Administration published Motorcycle Road Safety Audit Case Studies (FHWA-SA-16-026) to help Federal, State, tribal, and local agencies understand conditions that affect the safety of motorcyclists so that these agencies, too, can learn how to address safety issues and identify opportunities for improvement through the RSA process. This report examines three sets of RSAs that were sponsored by FHWA to demonstrate the benefits of using this process to reduce motorcycle-related fatalities, injuries, and crashes. An effective motorcycle RSA will identify countermeasures across the 3Es of safety—engineering, enforcement, and education.

Conducting RSAs to Select Engineering Countermeasures

Data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System (FARS) show that, in 2015, the most harmful event for 54 percent of motorcyclists involved in fatal crashes was a collision with another vehicle on the roadway. To a lesser degree, motorcyclists also are frequently involved in fatal collisions with fixed objects. About a quarter of the cyclists involved in fatal crashes in 2015 collided with fixed objects, compared to 17 percent for passenger cars, 13 percent for light trucks, and 4 percent for large trucks.

In two-vehicle crashes in 2015, 74 percent of those that involved motorcycles were frontal collision crashes. Of two-vehicle crashes between a motorcycle and another type of vehicle, 41 percent occurred when the other vehicle was turning left across the motorcyclist’s path, was involved in passing, or was attempting to overtake other vehicles.

Engineering Strategies for Motorcycle Safety

Engineering strategies targeted to motorcycle crashes include the following:

  • Provide full paved shoulders to accommodate roadside motorcycle breakdowns.
  • Consider motorcycles in the selection of roadside barriers.
  • Identify pavement markings, surface materials, and other treatments that reduce traction for motorcycles, and replace those with high-friction surface treatments.
  • Maintain the roadway to minimize surface irregularities and discontinuities.
  • Reduce roadway debris—such as gravel, shorn treads, snow and ice control treatments (sand/salt), and detritus resulting from uncovered loads—from the roadway and roadside to help avoid motorcyclists losing control and entering the opposing lane.
  • Provide advance warning signs to alert motorcyclists of reduced traction and irregular roadway surfaces.
  • Incorporate motorcycle safety considerations into routine roadway inspections.
  • Provide a mechanism for notifying highway agencies of roadway conditions that present a potential problem for motorcyclists.

Source: NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volume 22: A Guide for Addressing Collisions Involving Motorcycles.

Speed-reduction pavement markings installed by the North Carolina Department of Transportation (NCDOT) give road users the illusion that they are going faster than they are to encourage motorcyclists to slow down as they traverse tight curves. The wide apron installed on the inside of the curve serves to collect gravel that washes down from the hillside, keeping this hazard off the roadway.

When it comes to motorcycle safety, transportation agencies can apply engineering strategies to mitigate specific environmental or roadway characteristics that lead to the types of crashes most frequently responsible for motorcycle-related fatalities and injuries. A wide variety of safety strategies using engineering countermeasures can be specifically targeted to combat motorcycle crashes. Unique site characteristics, however, may mean that some countermeasures will have greater positive impact than others.

For example, a motorcycle RSA conducted in North Carolina on NC–28 and NC–143—routes characterized by a winding alignment; numerous driveways, commercial entrances, and intersections; and a dense tree canopy—determined that motorcyclists were crossing the center line. Crash data also demonstrated a prevalence of head-on and sideswipe opposite-direction crashes.

The RSA team determined that several countermeasures would improve safety on the routes, including clearing vegetation to improve sightlines around curves and the addition of warning signs for intersecting roadways. Some motorcycle-specific recommendations included paving shoulders on the inside of curves, especially gravel shoulders, as motorcyclists may try to steer away from these to avoid debris. Repainting center lines and adding center line pavement markings through intersections would help motorcyclists maintain visual focus. In addition, the RSA team believed that adding motorcyclist-specific signage or lane pavement markings at critical locations, such as at vertical (sag or crest) curves that also have horizontal curvature, would reduce crashes.

Another team conducted an RSA on a segment of the Blue Ridge Parkway in North Carolina, which is also characterized by a winding roadway with significant variations in alignment and multiple spiral curves. The data indicated that motorcycle crashes were by far the most common type of crash along curve segments in the study area. One factor might be that motorcyclists are largely a visitor population unfamiliar with the parkway’s attributes.

In this study area, recommendations included implementing a program to install the SafetyEdgeSM countermeasure along the parkway roadside. The SafetyEdge is an effective solution for reducing run-off-road crashes because it makes the transition back onto the pavement easier. It involves shaping the edge of the pavement to a 30-degree angle using a commercially available device (called a shoe) that can be attached to the paver. The asphalt is extruded under the shoe, resulting in a durable edge that resists edge raveling.

An FHWA evaluation of the SafetyEdge indicates that application of the measure has led to an estimated reduction of nearly 6 percent in total crashes on two-lane highways. Because of the low cost of the device, FHWA found the benefit-cost ratio for installation on two-lane roads ranged from 4 to 63. The RSA team members in North Carolina suggested that this countermeasure might be particularly effective in areas with higher traffic volumes, along curves, or at locations where data suggest motorcycles run off the road.

This enhanced curve warning sign on NC–143 targets motorcyclists.
Shown here are examples of warning signs that depict the locations of intersections along a curve. Signs like these could be used in Washington on SR–7, where intersections on curves present sight-distance challenges.

Washington State conducted an RSA on State Route (SR) 7 from milepost 16 to 59. The study area was divided into three focus areas: one urban segment and two rural segments. The study of the urban focus area, from the intersection of SR–7 and 182nd Street to the intersection with Interstate 5, revealed numerous driveways that make it possible for drivers to turn onto both directions of SR–7, creating many conflict points. Also, because turning drivers have to cross many lanes of traffic, their ability to judge acceptable gaps in traffic is reduced, which may have made it difficult for drivers to see oncoming motorcyclists.

The RSA team suggested that, in the medium term, turns into and out of driveways onto both directions of SR–7 should be restricted using signage, pavement markings, and physical barriers to prevent left turns except in select locations. In the long term, the team suggested developing a revised corridor access management plan that would take into account the needs of motorcyclists.

In addition, the RSA team suggested some short-range actions for other RSA sites on the SR–7 corridor to improve motorcycle safety, such as installing intersection warning signs that indicate an upcoming intersection, installing reflective post-mounted delineators that are evenly spaced throughout both sides of curves, applying wider edge lines and center lines, and installing shoulder rumble strips.

Selecting Education And Enforcement Countermeasures

Education and enforcement, the other two elements of the 3Es, often go hand in hand with engineering countermeasures. For example, collisions with fixed objects represent a significant factor in motorcycle crash fatalities, accounting for more than 25 percent of fatal motorcycle crashes in 2014, and motorcycles are more likely to be involved in such crashes than any other vehicle type.

Carefully maintaining the brightness and retroreflectivity of a 6-inch (15- centimeter) white edge line like the one shown along this roadway can provide positive guidance to help motorists navigate tight horizontal curves more safely.
Enforcement Strategies for Motorcycle Safety

Enforcement strategies that can help reduce motorcycle crashes and fatalities include the following:

  • Target law enforcement to specific motorcycle rider impairment behaviors that have been shown to contribute to crashes. Specifically, 17 cues have been identified to help law enforcement officers discriminate between impaired and normal operation of a motorcycle. Highway agencies should consider partnering with enforcement officials to support officer training in detecting these cues.
  • Expand existing impaired driving prevention programs to include motorcycle riders and specific motorcycle events.
  • Increase awareness of the causes of crashes due to unlicensed or untrained motorcycleriders.
  • Ensure that licensing and rider training programs adequately teach and measure skills and behaviors required for crash avoidance.
  • Identify and remove barriers to obtaining a motorcycle endorsement.

Source: NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volume 22: A Guide for Addressing Collisions Involving Motorcycles.

Part of the reason for this might be that more than a quarter of the motorcyclists who are fatally injured each year do not have a valid motorcycle license. This statistic possibly indicates a connection between lack of adequate training and an inability to maneuver the vehicle well enough to avoid fixed-object collisions in the event of a roadway departure.

During another motorcycle RSA conducted on SR–7 in Washington State—this one on an 11-mile (18-kilometer) segment of the highway—the Washington State Department of Licensing (WSDOL) provided data indicating that 30 percent of those killed in motorcycle fatalities on State roadways did not have the appropriate licensure or training to operate a motorcycle. The WSDOL data also showed a clear link between riding experience and fatalities: One-third of all motorcyclist fatalities involved motorcyclists with 2 years of riding experience or less.

The RSA team suggested several actions to improve the competence of riders and, by extension, their ability to navigate the SR–7 study site. The team suggested that safety courses that offer training in advanced riding techniques could help reduce the prevalence of collisions with fixed objects. In addition, transportation and enforcement agencies should place increased emphasis on the education and training opportunities provided through WSDOL’s motorcycle safety program. As part of this effort, these agencies were encouraged to reach out to a nearby military base and work with base staff to publicize and encourage motorcycle training and education to service members.

Educational Strategies for Motorcycle Safety

Educational strategies that involve partnering with the public and conducting public outreach include the following:

  • Increase awareness of the benefits of high-visibility clothing.
  • Identify and promote other methods and technologies to enhance rider visibility, such as auxiliary brake lights and daytime headlights.
  • Form strategic alliances with the motorcycle user community to foster and promote safety and training in advanced riding techniques.
  • Increase awareness of the consequences of aggressive riding, riding while fatigued or impaired, unsafe riding, and poor traffic strategies.
  • Educate operators of other vehicles to be more conscious of the presence of motorcyclists.
  • Increase the use of helmets compliant with Federal Motor Vehicle Safety Standard 218.

Source: NCHRP Report 500: Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volume 22: A Guide for Addressing Collisions Involving Motorcycles.

The RSA team also suggested that increasing the level of active enforcement of motorcycle licensing laws at locations with high crash rates is another approach that can prove effective in reducing crashes.

On the other side of the country, the North Carolina RSA suggested a somewhat different approach. There, some segments of the study sites were famous among motorcyclist communities for their challenging horizontal and vertical curvature and attracted motorcyclists of all experience levels, many from out of State. In fact, data from the North Carolina Department of Transportation (NCDOT) suggested that only about 15 percent of motorcycle fatalities involved motorcyclists from within the State. Because there are no national standards in terms of motorcyclist training and licensure, there are broad inconsistencies in skill level among motorcyclists who travel the studied corridors on NC–28 and NC–143.

In this case, the RSA team emphasized education, suggesting that NCDOT and law enforcement begin to collaborate with riding clubs, the division of motor vehicles, safety groups, and emergency medical services to provide riding safety education. The team also suggested creating and posting online safety information that will rank highly in Internet search engines. It is easy to find information on the Internet that emphasizes the more “thrilling” aspects of riding a motorcycle on these roads in North Carolina, but not so easy to locate safety information.

Motorcycle Crashes from the North Carolina Perspective

The terrain in North Carolina varies from broad coastal plains in the east to scenic mountain ranges in the west. The mountains draw motorcyclists from all over the country who see them as a place to test their skills.

“That creates some challenges for us,” says Brian Murphy, P.E., a safety planning engineer at NCDOT. “We want these riders to come and enjoy themselves, but we also want them to be able to drive back home.”

Murphy adds, “We’ve learned that just because motorcycle crashes often involve speed and other driver behavioral factors, there are still treatments that can help.”

A series of motorcycle safety reviews that NCDOT has conducted since 2011 has created a new perspective in the agency about identifying countermeasures targeted to motorcycle crashes.

“I would definitely recommend that a motorcycle expert be part of the RSA team,” Murphy says. “We had a motorcycle driving instructor [at the last RSA we conducted], and he was really looking at the site from the perspective of the motorcycle rider. His input was invaluable. It has been a real learning experience.”

At many of the sites NCDOT looked at, a large majority of the crashes involved motorcycles (more than 90 percent in some cases). Although other types of vehicles also travel through these sites, crash levels for those were much lower. As a result, NCDOT has implemented a variety of safety countermeasures that have been specifically targeted to motorcycle riders.

One effort involves adding plaques below standard roadside advisory signs that are specifically targeted to motorcyclists. Another countermeasure is applying speed-reduction pavement markings that begin in advance of specific curves and run through them. The markings give drivers the illusion that they are going faster than they are, influencing them to slow down as they enter the curve.

Beginning in 2015, the agency also has implemented dynamic sequential curve warning signs in two locations. Although it is too soon for the agency to have crash data, staff hope that those will have positive crash-reduction benefits as well.

Addressing the fact that many motorcyclists come from outside the State, NCDOT is constructing informational pulloffs in scenic areas where advisories and information specifically for motorcyclists can be posted so that riders can be prepared to navigate the roadahead.

An important but perhaps overlooked factor that the NCDOT safety staff learned from the motorcycle RSAs was about gravel on the roadway as a safety issue. In response to RSAs that identified areas where gravel washes down from the mountains onto the roadway, the agency installed large paved aprons to keep it off to the side and out of the roadway.

Perhaps the biggest takeaway from the North Carolina experience with motorcycle RSAs is that many of these countermeasures are transferrable to other sites.

“We couldn’t conduct an RSA at every site with higher-than-expected motorcycle crashes,” says Murphy, “but a lot of the recommendations from the safety reviews we did complete are being implemented at other sites throughout the State that have similar issues.”

Many of the countermeasures that North Carolina has implemented have been installed within the past 2 years, so not enough data are available regarding how effective the treatments have been. However, NCDOT is planning to begin conducting before and after analyses in 2017–2018 to determine which countermeasures have proven to be the most effective.

Photo. A scenic pulloff on a highway includes a large white sign that features an outline of the winding road ahead and a motorcycle advisory. The text reads, “Steep winding road, 20 mile per hour turns, next 18 miles, High Incident Corridor.

A pulloff in North Carolina features motorcycle advisory information on a white sign targeted to motorcyclists to prepare them for the challenges of the road ahead.

In addition, the team suggested working with the Tennessee DOT, which also hosts a segment of the Blue Ridge Parkway, to focus joint education efforts on the most vulnerable riders, including those with the least experience. Finally, the team suggested that posting signage at key locations to communicate motorcycle crash statistics on high-crash segments might induce motorcyclists to drive more carefully, while signs that indicate the fine for speeding might induce them to drive more slowly.

Research Efforts to Advance Motorcycle Safety

From a broader perspective, important gaps exist between what we know and what we need to know to make motorcyclists safer. A recently completed analysis by FHWA assessed the lack of available average annual daily traffic (AADT) data for motorcycles and described the impact of this gap on practitioners’ ability to perform evaluations aimed at developing motorcycle-specific crash modification factors. Existing advanced safety analysis tools, namely the American Association of State Highway and Transportation Officials’ (AASHTO) Highway Safety Manual, rely on the availability of roadway AADT data; however, the data are seldom disaggregated to show motorcycle-specific AADT.

Additional gaps in the types of crash data collected and in the availability of roadway inventory data, especially on low-volume roadways, exacerbate the challenge of increasing the transportation community’s understanding of what is happening when motorcycles crash and why. Furthermore, very little information is known about the impacts of roadway geometric and traffic control features on motorcycle crash frequency and severity.

A recently completed FHWA study will help to better define these and other existing gaps and form the basis for a roadmap that will lead to more information. FHWA’s Motorcycle Crash Causation Study, the most comprehensive research into the causes of motorcycle crashes in the United States in more than 30 years, concluded in 2016, although its findings are not available as of the writing of this article. The dataset collected in the study includes data from 350 or more crash investigations and 700 interviews with control riders, who were not involved in crashes but were exposed to similar riding environments. Partners from Federal agencies, State DOTs, local police jurisdictions, and the motorcycle industry support the effort and are optimistic that the data will offer significant insight into countermeasures.

Another effort, the FHWA Office of Safety’s Intersection Safety Program, once complete, is intended to leverage the data from the Motorcycle Crash Causation Study to develop additional insights. The researchers will use this new dataset to inform a study currently underway that is exploring the risk characteristics of intersections relative to motorcycle-involved fatal crashes and infrastructure strategies that could address those risks. Program staff are optimistic that a great deal will be learned, as roughly two-thirds of the investigated cases in the Motorcycle Crash Causation Study occurred at intersections.

Moving Forward

Motorcycle safety is increasingly relevant as the number of motorcyclists on the Nation’s roadways increases. While several important studies are underway to improve the ability to identify and mitigate safety risks to this vulnerable user group, the tools available today, including motorcycle RSAs and the implementation of innovative countermeasures such as those being applied in North Carolina and Washington State, can be effective in treating areas where motorcycle crashes are a concern. Motorcycle RSAs are an important tool for identifying specific crash treatments that will be most effective in improving safety on segments where motorcycle fatality and injury crashes are overrepresented. To date, 40 States are addressing motorcycle safety with 184 strategies across 53 emphasis areas. Several States also have created motorcycle safety coalitions to address motorcyclists’ concerns.

At the Federal level, increasing crash rates among motorcyclists have sharpened the focus on their safety. The Fixing America’s Surface Transportation (FAST) Act, signed into law in December 2015, reinstated a Motorcyclist Advisory Council to advise the FHWA administrator on ways to improve the roadway infrastructure for motorcycle safety, specifically with regard to barrier and road design, construction, maintenance, intelligent transportation systems architecture, and implementation.

“We are looking forward to the new [council] helping us to identify innovative ways to improve roadways for motorcycle safety,” says Michael Griffith, director of the FHWA Office of Safety Technologies.

In the meantime, FHWA encourages agencies to use RSAs to identify the most pressing problems that contribute to overrepresentation of motorcycle crashes on local roads. As shown in the RSAs highlighted in Motorcycle Road Safety Audit Case Studies (FHWA-SA-16-026), the multidisciplinary perspectives that team members bring, coupled with the inclusion of experienced motorcyclists, can be critical factors in defining effective methods to improve motorcycle safety using RSAs and the 3E approach.

Guan Xu, P.E., manages the Motorcycle Safety and Speed Management Programs in the FHWA Office of Safety. She has been with FHWA since 2003 and holds a master of science degree in civil engineering from the University of Cincinnati.

Rebecca Crowe is a transportation specialist in the FHWA Office of Safety. She has been with FHWA since 2001 and has a B.S. in urban planning and a master’s degree in transportation policy, operations, and logistics from George Mason University.

Gabe Rousseau, Ph.D., is the safety operations team leader in the FHWA Office of Safety. He has been with FHWA since 2002 and holds a Ph.D. in cognitive and experimental psychology from the University of Georgia.

Lisa Kinner Bedsole is a senior technical writer with Leidos in Reston, VA. She has supported FHWA’s Office of Safety outreach and communications efforts since 2005. She holds a B.A. in classics from the University of Mary Washington.