The National Park Service (NPS) has been at the forefront of the e-bike debate in the United States by permitting these modern marvels of micro-mobility on trails in national parks where regular, "analog" bike use is allowed.
The park service has produced a detailed literature overview of nearly 60 e-bike studies. The literature review revealed the following conclusions related to safety and e-biking.
Safety and E-bikes
"... more than half of the e-bike users stated they feel safer on an e-bike than a traditional bicycle because they can keep up with vehicular traffic..."
- Compared to traditional bicycle riders, e-bike users tend to have a higher rate of single-bicycle crashes.
- E-bike crashes have been increasing in general, but this could be attributed to the increasing trend of e-bike ownership.
Perceptions of E-bike Safety
Demographic Differences Among E-bikers
- Some e-bike users feel safer on e-bikes than on traditional bicycles for reasons related to the speed and acceleration characteristics of e-bikes.
- In a survey, non-e-bike riders indicated that they did not want e-bikes on trails because they were concerned that the e-bikes would travel too fast. However, the speed data showed that people using traditional bicycles traveled faster along the downhill sections than the people using e-bikes. The results of the study indicated that perceptions did not align with the observed behavior.
- The average cyclist may be able to travel faster using an e-bike than a traditional bicycle; however, this does not mean that people necessarily travel at higher speeds when using e-bikes.
- E-bikes generally travel at similar speeds as traditional bicycles on roadways, off-street paths, as well as natural surface trails. Depending on context, e-bikes may travel faster or slower than traditional bicycles.
- Higher average speeds for e-bikes may be due to e-bikes having faster uphill speeds. Measured speeds along flat and downhill sections were relatively similar along both roadways and natural surface trails.
- E-bike riders tend to be older.
- Men have a higher rate of crashing than women.
- Women, older adults, and people who consider themselves not physically fit have a higher rate of suffering a serious injury.
E-bike Rider Behavior
- Compared to traditional bicyclists, e-bike riders exhibit nearly identical safety behavior for wrong-way riding, stop sign compliance, and traffic signal compliance.
- Similar to traditional bicycles, speeding on e-bikes can lead to an increase in crashes, especially when weather conditions are not ideal.
- Trail users stated that, with respect to passing distance and passing speed, the behavior of people using traditional mountain bikes and eMTBs was indistinguishable.
E-bike Trip Purpose
- Those who use e-bikes to commute tend to have a higher crash risk than those using e-bikes for recreation.
- eMTBs (with wider tires and better suspension) have a lower crash risk than other e-bike types.
- Class 3 e-bike have similar crash rates as Class 1 or Class 2 e-bikes, however Class 3 may have more serious injuries.
- There is a lack of research on whether and to what extent there are differences in safety risks between e-bike classes.
- Since e-bike classifications are not usually reported in crash statistics, it is difficult to draw conclusions about safety differences among e-bike classes.
"The NPS strives to protect public health and safety and provide for injury-free visits. In National Park System units, safety is critical to bicyclists, hikers, and other trail users. Safety considerations are particularly important on remote trails, where rescue and emergency response may be more difficult. It is acknowledged that determining the safety of e-bikes and the behavior of e-bike riders is an important factor in determining whether e-bikes should be managed differently than traditional bicycles."
"Initial research on the safety implications of e-bikes tended to originate from Europe or China. Despite the cultural and geographical differences of this international research, these studies can still inform a basic understanding of how riders behave while using e-bikes. E-bike ownership has steadily grown over the past decade, and with it, the availability of data, reports, and research studies related to safety. The primary method for measuring safety is through reported crash incidences and available crash data, which characterizes the frequency and severity of accidents."
E-bike Safety Key Findings
"Perceptions of Safety Key Findings
In a North American survey, more than half of the e-bike users stated they feel safer on an e-bike than a traditional bicycle because they can keep up with vehicular traffic when bicycle facilities (e.g., protected or dedicated lanes) aren’t present, have quicker acceleration through dangerous intersections, are able to accelerate away from unsafe social situations, take longer routes to avoid busy roads and intersections, and aren’t as likely to lose concentration due to physical exertion."
"Perceptions of Safety Areas for Further Research
More research could inform improved understanding of the discrepancy in attitudes towards e- bikes and safety outcomes among different demographic groups. Most studies that assess perceived safety aspects of e-bikes do so through surveys which are subjective and can be subject to bias. Studies that pair surveys with observational or other empirical approaches may help identify disconnects between perceived and actual safety."
"Speed Key Findings
Much of the research on e-bike safety has focused on their speed compared to traditional bicycles. Class 1 and Class 2 e-bikes provide electric assistance up to 20 mph and Class 3 e-bikes provide electric assistance up to 28 mph. The average cyclist may be able to travel faster using an e-bike than a traditional bike; however, this does not mean that people necessarily travel at higher speeds when using e-bikes.
Studies have evaluated the spot speed (speed at a specific location), average speed, and top speed of e-bikes. (Johnson, M.) Spot speeds, when going uphill, tend to be higher for e-bikes than for traditional bicycles. The research shows that e-bikes may have higher average speeds specifically because of the higher spot speeds during the uphill climbing sections even though the top end speeds on flat and downhill sections are similar between the e-bikes and traditional bikes."
"Another study found that e-bike riders along shared use paths, on average, travel slower than traditional bicycles. (Langford, C.) Some e-bike users feel safer on e-bikes than traditional bicycles, citing speed advantages that allow them to keep up with traffic, accelerate more quickly through dangerous intersections, and away from unsafe social situations.
Speed Areas for Further Research
Traditional bicycle speeds can vary significantly from one bicycle or cycling context to another; for example, an experienced cyclist riding a road bike for a 50-mile route will travel at higher speeds than a leisurely cyclist riding a cruiser bicycle to pick up groceries on the way home from work. Further research could compare e-bike speed to that of different types of traditional bicycles in multiple cycling contexts."
Academic Research – User Conflicts: Most Other Trail Users Cannot Differentiate Between a Traditional Bicycle and an E-bike on Trails
Academic Research – Safety: E-bikes Generally Travel at Speeds Similar to Traditional Bicycles on Roadways, Off-street Paths, and Natural Surface Trails
Academic Research – Nature and Environment: E-bikes Have Order-of-Magnitude Lower Lifecycle Greenhouse Gas and Air Pollutant Emissions than Internal Combustion Engine Vehicles
Academic Research – Equality: The Gender Discrepancy Between E-bike Users is Proportionally Lower than that of Traditional Bicycle Users in the United States
Academic Research – Access: E-bikes Provide a New Option to Cycle Regardless of Physical Fitness, Age, Disability, Recent Injury, High Altitude, or Challenging Terrain
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"Demographic Differences Key Findings
Research has shown that e-bikes attract different types of riders than traditional bicycles, specifically appealing to older riders. A study in Switzerland found that the average age of e-bike riders involved in crashes was between 40-65 years old. The same analysis found that e-bike riders were involved more in single-bicycle crashes than traditional bicycle riders. (Weber, T.) A study in the Netherlands found that older riders are more prone to single bicycle e-bike crashes because of the difficulty with balance in handling the heavier weight of the bikes during a dismount (Schepers, P.)"
"Another study looking at e-bike rider behavior in Switzerland found that, on average, men have a higher risk of crashing than women. However, the risk of suffering a serious injury is higher for women, older adults, and those who consider themselves not physically fit. (Hertach, P.) As with traditional bicycles, the rider’s level of experience and cycling proficiency may also affect their risk of crashing."
Demographic Differences Areas for Further Research
There is not yet any research available which specifically measures e-bike effects to wildlife and vegetation, so the specific effects of e-bikes on the ecological system are still not well understood. There is a lack of research studying potential e-bike effects such as noise and plant trampling compared to traditional bicycling, mountain biking, or other forms of non-motorized outdoor recreation."
"Rider Behavior Key Findings
Several studies have used GPS devices to track rider behavior. The data showed that e-bike riders exhibit nearly identical safety behavior for wrong-way riding, stop sign compliance, and traffic signal compliance, as traditional bicycle riders. All types of cyclists have a poor compliance rate at stop signs and at traffic signals. Other studies have looked into the reasons for e-bike crashes. A study in Switzerland found that the most common crash causes were slippery road surfaces and inappropriate speeds and the most common crash mechanism was skidding and falling. This indicates that the speeding behavior can lead to an increase in crashes, especially when weather conditions are not ideal. (Hertach, P.)
In another study where e-bikes were recently allowed on trails, other trail users stated that the behavior of people using traditional mountain bikes and eMTBs was indistinguishable. Both bicycle riders behaved similarly in terms of passing distance, passing speed, and general attitude of sharing the trial."
"Rider Behavior Areas for Further Research
Although there is an increasing trend of e-bike crashes, this could be attributed to the increasing trend of e-bike ownership. More research, including regression analyses, could determine whether crash rates are growing faster than e-bike ownership rates, and what other factors are associated with e-bike crashes.
An area for further research is to study rider behavior of e-bike users along natural surface trails compared to the behavior of traditional cyclists (e.g., are e-bike riders more or less likely than traditional cyclists to travel off of established natural surface trails?)."
"Trip Purpose Key Findings
The purpose of an e-bike trip can influence safety risk. For instance, a Swiss study found that, on average, those who commute to and from work using e-bikes have a higher risk of crashing than those using e-bikes for recreation. (Hertach, P.) The study also found that riders who used eMTBs (which typically have wider tires and better suspension) had a lower crash risk than riders of other e-bikes.
A number of recent studies have tried to determine what modes are most commonly being replaced by e-bike trips and have yielded mixed results. Overall, the research suggests that e-bikes are most commonly replacing trips taken by a traditional bicycle but are also likely leading to a reduction in vehicle miles traveled by personal automobile. The people that switch from a traditional bicycle to an e-bike typically travel further distances, can carry more cargo items, and use it more frequently for commuting and daily errands."
"Trip Purpose Areas for Further Research
Further research could inform better understanding of the causal factors behind the relationship between trip purpose and safety risk. Recreational riders may have fewer distractions, ride in areas with fewer traffic conflicts, and plan their trips in a way to avoid traffic conflicts. Commuters in urban areas tend to face more obstacles and traffic conflicts."
"This theme of the literature review is organized around six sub-topics: perception of safety, speed, demographic differences, rider behavior, trip purpose, and e-bike classifications."
Perception of Safety
Johnson, M. (2015). Safety Implications of E-bikes. Royal Automobile Club of Victoria.
"This study includes a literature review on perceptions of safety, a review of the current infrastructure design standards, and a survey of e-bike riders exploring their experiences and perceptions of safety. The survey found that hill climbing capability and spot speed are two potential e-bike performance capabilities that are different from traditional bikes in terms of how a rider interacts with on-road and off-road infrastructure.
A spot speed is the speed at a specific location (e.g., at an uphill section) as opposed to average speed. There is no significant difference between e-bike and traditional bike riders in perceptions of comfort, including safety, or on a rider’s perspective of cycling infrastructure. E-bike riders were found to be older riders with less riding experience, finding that “almost four in ten female e-bike riders had not been cyclists before purchasing or riding an e-bike.” When compared to using a traditional bicycle, e-bike riders generally felt as safe on loose gravel surfaces, that they accelerate faster, that they could ride at higher speeds, and that it is not harder to stop."
Langford, B., Chen, J., Cherry, C., (2015). Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders. Accident Analysis & Prevention, 82. https://www.sciencedirect.com/science/article/pii/S0001457515001992?via%3Dihub
"This is the first study to rely on naturalistic GPS data for bicycle and e-bike safety. A study was conducted using the pilot bikeshare implemented at the University of Tennessee that offered six traditional bicycles and 14 Class 1 e-bikes. Riders of e-bikes travel at higher speeds than traditional bicycles on roadways (about 2.9 kph). Riders of traditional bicycles travel at higher speeds than e- bikes on shared-use paths (about 1.6 kph). Speed on natural surface trails were not identified in the study.
Over the course of the pilot, the data showed that e-bike riders exhibit nearly identical safety behavior for wrong-way riding, stop sign compliance, and traffic signal compliance, as traditional bike riders. However, all cyclists had a poor compliance rate at stop signs (about 80% when traveling at 6 kph and about 40% when traveling at 11 kph) and at traffic signals (about 70%)."
Petzoldt, T., Schleinitz, K., Jeilmann, S., Gehlert, T. (2016). Traffic conflicts and their contextual factors when riding conventional vs. electric bicycles. Transportation Research Part F: Traffic Psychology and Behaviour. https://www.sciencedirect.com/science/article/abs/pii/S1369847816300924
"This study examined if there are differences between traditional cyclists and e-bike riders with regard to the probability to be involved in a traffic conflict. The study investigated the circumstances under which conflicts occur to identify potential differences in risk.
Researchers equipped the personal bicycles of 80 participants (31 traditional cyclists and 49 e-bike riders) with a data acquisition system that included two cameras and a speed sensor. Four weeks of “normal” cycling were recorded for each participant. The analysis showed no difference between bicycles and e-bikes with regard to their overall involvement in traffic conflicts.
One notable exception were intersections, where the risk of being involved in a conflict was twice as high for e-bikes as for traditional bicycles. The speed immediately preceding a conflict was higher for riders of e- bikes compared to traditional bicycles, a pattern that was also found for mean speed."
Nielson, T., Palmatier, S., Proffitt, A., Marotti, M. (2019). Boulder County E-bike Pilot Study Results. https://assets.bouldercounty.org/wp-content/uploads/2019/09/e-bike-pilot- study.pdf
This report highlighted the results of two studies, an intercept survey and a speed observation study, conducted for the e-bike pilot program allowing Class 1 and Class 2 e-bikes on certain county open space trails in Boulder County, Colorado. The speed study included 12 identified e- bikes out of 503 total bike observations. People on traditional bikes traveled faster than e-bikes on downhill sections (15 mph vs 13.5 mph) and people on e-bikes traveled faster than traditional bikes on uphill sections (13.8 mph vs 12.9 mph).
Weber, T., Scaramuzza, G., Schmitt, K. (2014). Evaluation of e-bike accidents in Switzerland. Accident Analysis & Prevention, 73. https://www.sciencedirect.com/science/article/pii/S0001457514002231
The study analyzed police-recorded crashes during 2011 and 2012 involving a total of 504 e-bikers and 871 traditional bicyclists along urban and rural roadway and bicycle infrastructure (the study did not state if crashes along recreational, natural surface paths were included). Most e-bikers who sustained a crash were 40–65 years old and only a few crashes with e-bikers below 23 years of age were reported. E-bikers in the urban area sustained less single and crossing crashes and more turning and other crashes compared to e-bikers in the rural area.
Schepers, P., Fishman, E., den Hertog, P., Wolt, K., & Schwab, L. (2014). The safety of electrically assisted bicycles compared to classic bicycles. Accident Analysis & Prevention, 73.https://www.sciencedirect.com/science/article/pii/S0001457514002668
"This case–control study compared the likelihood of crashes for which treatment at an emergency department is needed and injury consequences for e-bike and traditional bicycle crash incidents in the Netherlands among users 16 years and older. Data were gathered through a survey of victims treated at emergency departments. Additionally, a survey of cyclists without any known crash experience, drawn from a panel of the Dutch population acted as a control sample.
The results suggest that, after controlling for age, gender, and amount of bicycle use, e-bike users are more likely to be involved in a crash that requires treatment at an emergency department due to a crash. When they occur, crashes with e-bikes are about equally as severe as crashes with traditional bicycles. The study did not state if crashes along recreational, natural surface paths were included."
Ma, C., Zhou, J., Yang, D., Fan, Y. (2019). Research on the Relationship between the Individual Characteristics of Electric Bike Riders and Illegal Speeding Behavior: A Questionnaire-Based Study. https://www.mdpi.com/2071-1050/12/3/799/pdf
"This paper obtained 350 survey responses from e-bike riders along a roadway when the rider was asked to stop to participate in our survey. Eight individual attributes were used as potential influencing factors of rider speed choice: rider’s gender, age, education level, years of experience riding an e-bike, rider’s personality characteristic (melancholic, phlegmatic, sanguine, and choleric temperament), job/occupation (students, incumbents, freelancers, and retirees), corrective vision, and cycling proficiency (novice, general, more skilled, skilled).
The following three rider attributes had the most significant relationship to the riding speed: education level, years of experience riding an e-bike, and riding proficiency. Riders with higher proficiency tend to ride faster. Riders with more years of experience tend to ride slower. As education level increases, riders travel at higher speeds with the exception of the highest education level (university and above) ride the slowest."
Fyhri, A., Johansson, O., Bjornskau, T. (2019). Gender Differences in Accident Risk with E-Bikes – Survey Data from Norway. Accident Analysis & Prevention. https://doi.org/10.1016/j.aap.2019.07.024
"This study aimed to investigate the crash risk regarding e-bikes and traditional bicycles. The study included a survey in nine Norwegian urban areas in 2017 where participants were asked about behavior and crash involvement. Then, a follow-up survey in Norway’s four largest cities in 2018 were given a more detailed questionnaire about their crash involvement. In this survey a crash was defined as “crashing, running of the road, or falling over, and resulting in damage either to [oneself] or to the bicycle.” The survey did not include information regarding the location of the crash (along a roadway or a natural surface path).
The study found an increased risk of crashes for women on e-bikes when compared with men. For men there was no risk difference found between e-bikes and traditional bicycles. Some of the elevated risk can be attributed to being unfamiliar with e-bikes, which could suggest a need for improved infrastructure or educational programs to improve safety. The study found that “e-bikes are not more likely to cause serious crashes than traditional bicycles.” Additionally, e-bikes are more often involved in balance-related crashes, but that crash type is rare."
Yang, H., Liu, X., Su, F., Cherry, C., Liu, X., (2018). Predicting e-bike users’ intention to run the red light: An application and extension of the theory of planned behavior. https://www.sciencedirect.com/science/article/abs/pii/S1369847817306976?via%3Dihub
"This paper aims to examine the psychological motivation of e-bike users that run red lights. A survey questionnaire was designed employing the construct of theory of planned behavior (TPB). The survey was performed in Chengdu, China in November 2016. Researchers found that users older than 40 identify themselves as more cautious riders.
Younger riders have higher intention to run the red light. During the review of existing literature, Yang and the team found that e-bike users were 1.834 times more likely to run the red-light than traditional bicycle users. Around 76% of e-bike users regarded running the red light as a dangerous behavior. The study noted that there are many factors contributing to the decision to run a red light, including wait time at the light. Attitude and perceived behavioral control had significant positive effects on intention."
Huertas-Leyva, P., Dozza, M., Baldanzini, N. (2018). Investigating cycling kinematics and braking maneuvers in the real world: e-bikes make cyclists move faster, brake harder, and experience new conflicts. https://www.sciencedirect.com/science/article/abs/pii/S1369847817304096?via%3Dihub
"The study showed naturalistic data from cyclists switching from a traditional bicycle to an e-bike on roadways. All cyclists rode faster on e-bikes than on traditional bicycles. Abrupt braking and sharp deceleration were higher when riding an e-bike than when riding a traditional bike. All cyclists required more reactive maneuvers braking when riding e-bikes then a traditional bike. Decelerations during sharp braking were higher riding e-bikes than traditional bikes."
Hertach, P., et al. (2018). Characteristics of single-vehicle crashes with e-bikes in Switzerland.
"This 2016 study surveyed 3,658 e-cyclists in German-speaking Switzerland. The main aim of this study was to gain more knowledge on the characteristics of single-vehicle crashes with e-bikes in road traffic. In this case, a single-vehicle crash was defined as crash that only involved the e-bike and the rider (for example, a collision with a fixed object, or skidding and falling). The other category was defined as “Involvement in a collision with another road user (pedestrian/cyclist/car).”
This study confirmed a few safety implications of e-bikes such as the risk for suffering a serious injury is higher for women, older adults, and those who consider themselves not physically fit. It also found that the most common crash mechanism was skidding and falling. In addition, on average, those who commute to and from work using e-bikes have a higher risk of crashing than those using e-bikes for recreation."
Cherry, C., MacArthur, J., (2019). E-bike safety: A review of Empirical European and North American Studies. https://wsd-pfb- sparkinfluence.s3.amazonaws.com/uploads/2019/10/EbikeSafety-VFinal.pdf
"This is a comprehensive white paper review of emerging research on e-bike safety in North America and Europe. This report focuses almost exclusively on objectively observed safety information and data, including records of safety proxies and crash or injury reports. The observed data is generally drawn from empirical studies or “naturalistic” rider behavior studies.
The white paper found that Class 3 e-bikes have the same crash risk as Class 1 e-bikes, but injury severity is slightly higher when they do crash. Class 1 e-bikes are marginally faster than traditional bicycles (3.0 km/hr). Their speed results in slightly higher conflict rates and safety-oriented maneuvers. Class 3 e-bikes travel substantially faster than traditional bicycles, about twice the speed on average. The review identified no definitive answer regarding whether e-bikes are more or less safe than traditional bicycling, and under which circumstances."
This is an interactive version of the NPS study. We have copied the text of the study verbatim on this page under Section 105 of the U.S. Copyright Act. The text and conclusions of the study are those of the NPS.
Krista Sherwood (Conservation & Outdoor Recreation Division) and Wayne Emington (Park Facility Management Division) are the points of contact for this outstanding literature review. The NPS is not affiliated or associated with E-bike Lovers.
Download the NPS study here.