Bicycle Safety Guide and Countermeasure Selection System

Bicycle Crash Statistics

The Background and Trends section provided an overview of the need to provide a more bicycle-friendly environment on streets and highways. This section provides an overview of the bicycle safety problem and related factors that must be understood to select appropriate facilities and programs to improve bicycle safety and mobility. A brief description of the bicycle crash problem in the United States is discussed in the Crash Analysis section. Similar crash analyses should be conducted for states and municipalities to better understand the specific factors that affect the safety and mobility of bicyclists and to select appropriate countermeasures.

Magnitude of the Problem

In 2012, 726 bicyclists were reported to have been killed in motor vehicle crashes in the U.S.1 Bicyclist deaths in 2012 accounted for 2.2 percent of the 33,561 motor vehicle-related deaths nationwide.2 An estimated 49,000 bicyclists were injured in motor vehicle collisions, representing 2.1 percent of the 2.3 million total persons injured in traffic crashes in 2012.2 While total traffic fatalities and injuries have steadily declined between 2002 and 2011, with a slight uptick in 2012, bicyclist fatalities and injuries in collisions with motor vehicles have remained relatively constant during the same period.2 For the 11-year period 2002-2012, the average number of bicyclist fatalities per year was 696 and the average number of bicyclist injuries was 47,273.2

Injury and Fatal Crashes, 2002-2012Line graphs of injury and fatality dataSource: National Highway Traffic Safety Administration. Traffic Safety Facts 2012: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System. Publication DOT HS 812 032. U.S. Department of Transportation.

The National Highway Traffic Safety Administration (NHTSA) makes available national data about fatalities and injuries that result from motor vehicle crashes. While these data provide some insight about the circumstances of bicycle-involved crashes, they provide little insight about bicycle volumes and potential crash exposure. Furthermore, these data are frequently referred to as the “tip of the iceberg” since these crashes are limited almost entirely to events that occur on public roadways. Possible exclusions include bicycle-motor vehicle crashes that occur in non-roadway locations, such as shared-use paths, parking lots, driveways, and sidewalks, as well as falls or other events that do not involve a motor vehicle or that go unreported by the bicyclist and driver involved. In a study using data collected at eight hospital emergency departments from three states, Stutts and Hunter found that 70 percent of the reported bicycle injury events did not involve a motor vehicle. In addition, 31 percent of the bicyclists were injured in non-roadway locations such as sidewalks, parking lots, or off-road trails.3

Bicyclists Most at Risk

While bicycle fatalities among children under age 16 have steadily declined over the last three decades, fatalities in the 16 and older age group have steadily increased.4 In 2012, bicyclists age 45-54 had the highest fatality rate based on population (3.93 per million population). Bicyclists under age 16 accounted for nine percent of all bicyclists killed and 20 percent of bicyclists injured in crashes with motor vehicles in 2012, which represent significant decreases since 2002.1 In addition to motor vehicle crash data, emergency room visit data from 2012 show that bicycle-related injuries are the fifth leading cause of non-fatal injuries for the 5-16 age group—constituting four percent of all injuries for that age group.5

In 2012, 88 percent of bicyclists killed and 80 percent of bicyclists injured in crashes with motor vehicles were male.1 Similarly, the fatality rate per capita was over seven times higher for males than for females, and the injury rate per capita was over four times higher for males.1 Crash injury rates by population in 2012 were highest for males between the ages of 10 and 15 (555 injuries per million population), and for females between the ages of 16 and 20 (144 per million population). Crash fatality rates for males remain high above age 45, while the fatality rate for females decreases significantly after the ages 45-54.1

Area Type

Crashes involving bicyclists occur most frequently in urban areas where pedestrian activity and traffic volumes are greater compared to rural areas. In 2012, 69 percent of bicyclist fatalities occurred in urban areas.1 While bicycle crashes occur more frequently in urban areas, a study analyzing crash data from North Carolina found that crashes in rural areas result in a higher percentage of disabling injuries or fatalities compared to urban crashes.6 In other words, crashes in urban areas occur more frequently; however, crashes in rural areas, though less frequent, tend to be more severe. This finding for rural areas may be related to higher motor vehicle speeds, while the high percentage of fatalities in urban areas is likely related to exposure.

Location Type

In 2012, roughly 60 percent of crashes resulting in a bicyclist fatality occurred at non-intersections. However, for bicyclist injury crashes, roughly 58 percent occurred at an intersection.2 More bicyclists may be killed at non-intersection locations than intersection locations because of higher speeds along the road; however, there are significantly more bicyclist injuries than fatalities, and injuries occur more often at intersections. Conflicting traffic patterns and behavioral factors such as lack of driver scanning for bicyclists and bicyclists not complying may be factors in these types of crashes.

Time of Occurrence

In 2012, bicyclist fatalities were most common after 4 p.m.1 The hours of 4 p.m. to 7:59 p.m. accounted for 24 percent of reported bicyclist fatalities, with another 24 percent occurring between 8 p.m. and 11:59 p.m. On weekdays, the highest percentage of bicyclist injuries and fatalities occurred between 3 p.m. and 6 p.m. (28.8 percent) and the highest number of fatalities occurred between 6 p.m. and 9 p.m. (22.3 percent). On weekends the highest percentage of injuries and fatalities occurred between 6 p.m. and 9 p.m. (28.9 percent and 24.9 percent, respectively).2 This is likely a combination of higher exposure (higher bicycle and vehicle volumes) coupled with reduced visibility in the late afternoon and evening.

Alcohol Involvement

Driving under the influence of alcohol is a well-publicized issue as related to motorists in this country. It is also an issue for bicyclists. Alcohol involvement for either the bicyclist or motor vehicle driver was reported in more than 37 percent of the crashes that resulted in a bicyclist fatality in 2012.1 About 28 percent of fatally injured bicyclists were reported to have a blood alcohol concentration (BAC) of 0.01 or higher, and 23 percent, a subset of the above group, had a BAC of 0.08.2 Alcohol crashes tend to involve older bicyclists and are more frequent on weekends and during hours of darkness.7 This type of information can help an agency target specific behaviors during specific times of day.

Bicycle Crash Factors

Wherever bicycling occurs there are a number of conditions that can increase crash risk for bicyclists. Efforts to improve these conditions should improve bicycle safety.

Wrong-way riding

Wrong-way riding, or riding facing traffic, remains a prevalent problem, except on designated facilities like two-way cycle tracks. This behavior puts bicyclists in a position where they are not expected by motorists, whether the bicyclist is in the street or on the sidewalk. An example is a motorist making a right turn out of a street or driveway—the motorist is looking primarily to the left for a gap in traffic and may not recognize a bicyclist riding against traffic, either in the street or on the sidewalk. This is also an issue for intersections with shared-use paths since path traffic in the contraflow direction will be approaching motorists in this manner.8

Man on bike riding on the sidewalk

http://www.pedbikeimages.org/ - Charles Hamlett

Sidewalk riding

Sidewalk riding is permitted in many, but not all, communities. If allowed on sidewalks, bicyclists should travel about the same speed that pedestrians walk—about 3 to 5 miles/hour. An inherent danger in sidewalk riding comes from the presence of driveways that cross the sidewalk. Motorists tend to drive across the sidewalk to get a better view of traffic, and this can lead to crashes with bicyclists riding on the sidewalk, especially those riding against the normal flow of traffic. This same potential conflict is also present at intersections, where bicyclists riding on the sidewalk may ride through the crosswalk, or bicyclists riding on a shared-use path adjacent to the roadway may ride into the path of motor vehicles. Motorists tend to expect pedestrians to emerge from sidewalks so they limit their scan distance, but when bicyclists make this maneuver and travel considerably faster than pedestrians, the potential for crashes is increased.

Presence of driveways

Besides the potential crashes involving motorists in driveways and bicyclists on sidewalks mentioned above, crashes also occur when motor vehicles pull into the street from a driveway and strike a bicyclist riding in the street. A variety of factors can affect these crashes, including the presence of on-street parking, a bicyclist riding at night without proper lights, and poor sight distance at the driveway.

Night bicycle riding

National crash data from 2012 indicate that 31 percent of all bicycling injuries from motor vehicle collisions occur between the hours of 6 p.m. and 6 a.m.2 Fifty percent of bicyclist fatalities occurred during this 12-hour span.2 This is partly an education issue for bicyclists. While not all of these crashes can be attributed to a lack of lighting or reflectors on the bicycle; local police, educators, and bicycling groups should be engaged in informing bicyclists of the proper riding equipment.

Bicyclists riding next to parked vehicles ("dooring")

Serious injury can occur when the driver or passenger of a parked vehicle opens a door without leaving time or space for bicyclists to react causing them to strike the open door. This may occur frequently on bicycling corridors that have on-street parking, especially areas with high parking turn-over.

Bicyclists not obeying traffic control at intersections

While many crashes near intersections are not the fault of bicyclists, a frequent factor in these crashes is the bicyclist who does not comply with traffic control at an intersection. In addition to bicyclist errors, factors that may lead to crashes at signalized intersections also include the lack of or inadequate detection of bicyclists and insufficient time for bicyclists to clear the intersection before a conflicting movement phase change.9 At sign-controlled intersections, crashes may result when bicyclists ride-through a stop sign or fail to yield, which they may do in an effort to reduce the amount of energy needed to regain momentum after slowing.8

Bicycle crashes involving children

Although bicyclists 25 years of age and older are increasingly involved in injury and fatality crashes, the number of crashes involving children under age 16 remains high. In 2012, children under the age of 16 accounted for 9 percent of bicyclist fatalities and 20 percent of bicyclist injuries.1 Crash types where this group is overrepresented include riding out or through intersections with stop signs, riding out at non-intersection locations such as driveways, turning or merging in front of traffic, and non-roadway crashes, including those in parking lots and driveways.8

Use of bicycle helmets

Many serious head injuries occur at low speeds and are preventable if helmets are worn properly. As of February 2013, 21 states, the District of Columbia, and at least 201 local jurisdictions have some form of mandatory bicycle helmet laws. Thirteen states have no state or local helmet laws of any kind.10

Numerous studies have found that use of approved bicycle helmets significantly reduces the risk of serious head, brain, and facial injury among bicyclists of all ages involved in all types of crashes and crash severities. One study that analyzed the results from 20 peer-reviewed studies estimates a 33 percent reduction of the risk of injury to the head, face, or neck if a helmet is worn. However, this study also confirmed the finding from previous studies that the risk of a neck injury increases when a helmet is worn.11