posted by John MacArthur on Wed, 11/26/2014 - 11:15am
Learn more about our other research on e-bikes here.
Over the last couple years, electric bicycles (e-bikes) have been gaining momentum. E-bikes may play an important role in addressing cities’ transportation and public health problems by getting more people out of cars and onto bicycles. But as the number of users increase, so too will potential conflicts (actual or perceived) with other road users, causing policy questions to arise.
The current state of e-bikes regulation varies dramatically across state and local jurisdictions, causing confusion. The confusion stems from the wide variety of devices and technologies on the market, perceived overlap of legal entities’ jurisdiction over the device, outdated or absent laws and regulations, and inconsistency of terms used to describe e-bikes. This confusion creates uncertainty for manufacturers and dealers and makes riders wary of embracing e-bikes.
One of the biggest concerns people have about e-bikes and their use, especially on shared-use paths, is speed. Currently, the Consumer Product Safety Act defines an e-bike as having a maximum speed of 20 mph when powered solely by a motor. Given the design specifications of an e-bike, do people tend to ride faster on an e-bike? If so, how much faster than on a conventional bicycle? Are e-bikes fast enough to cause concern or problems on bike facilities?
First, we need to look at the speeds of conventional bicycles. Opiela et al. measured the speeds of bicycles on various bike facilities and found the average speeds ranged around 12-15 mph and maximum speeds reached 24-25 mph (Table 1. The 2012 American Association of State Highway and Transportation Officials (AASHTO) Guide for the Development of Bicycle Facilities suggests speed performance criteria for bike facilities: 8-15 mph paved level terrain; 20-30+ mph for downhills; 5-12 mph for uphills; and a 15 mph average operational speed.
Table 1: Bicycle speed on facilities (Opiela et al., 1980)
There is some sentiment that devices that can go 20 mph or faster probably do not belong in bicycle lanes and shared-use paths. Is this truly an issue solely focused on the use of e-bikes? Crashes on facilities have recently caused a discussion of speeds of conventional bikes and the conflicts with pedestrians and other cyclists. In New York City’s Central Park, bicycles have been shown to reach 25-32 mph on crowded sections of the park’s roadway. Other cities do have posted speed limits on facilities and do occasionally try to enforce these limits.
The question of how fast e-bikes are and where they should be ridden has been a growing topic of discussion both at the state and local policy level, and has been especially debatable and contentious if they don’t look like a standard bicycle (i.e., scooter-type).
There have not been many research studies comparing conventional vs. e-bike speeds in natural settings. A study of the University of Tennessee’s electric-bike share program showed that both the average speed and maximum speed of e-bikes were slightly higher (approximately 3 mph) than conventional bicycles (Table 2). On shared use facilities, conventional bicycle users had slightly higher average travel speeds than e-bike users, 7.8 mph versus 6.8 mph respectively. They also have slightly higher average top speeds across all roadway segments, 16.0 mph for conventional bicycle users versus 15.8 mph for e-bike users.
Table 2: E-bike vs. conventional bike speed (Langford, 2013)
Another study in Sweden showed a much lower variance of e-bike speeds compared to conventional bicycles, though reported average speeds were approximately 5 mph higher (Dozza, Werneke & Mackenzie, 2013). It is interesting to note that the maximum speeds were about the same for each class.
Figure 1: Comparison of e-bike and conventional from a naturalistic-cycling study in Sweden (Dozza et al., 2013)
Finally, the City of Boulder has been conducting a pilot project to determine whether e-bike users can coexist with other users on multi-use paths. As part of the pilot project, speed observations were conducted at four locations with 16-17 mph representing the 85th percentile of speed of all cyclists and 60-70% of cyclists traveling at or below the 15 mph speed limit for the facility. Out of the 1,015 riders observed, only two e-bikes were observed and both were going under 15 mph.
These initial studies show that e-bikes are indeed faster on average than conventional bicycles but well within the design standards of bicycle facilities. Transportation planners, bike and pedestrian advocates and users of bicycle facilities should be concerned about speeds on these facilities but it might not be appropriate to focus only on e-bikes or to put restrictions on this specific class of bicycles.
Transportation planners and policymakers must evaluate their bicycle facilities to determine if e-bikes ought to be permitted and include the e-bike community in outreach and communication programs. However, in order for planners and policymakers to rationally evaluate the potential impact of e-bikes on their facilities, more robust data on e-bikes are needed. More research is needed on the safety implications of e-bikes and the collection of real-life data to help understand the true differences between e-bikes and conventional bicycles. It is uncertain how the dynamics of bike facilities will operate if the average speeds do increase with higher proportions of e-cyclists. One specific issue that is starting to be raised is on the class called “s-pedelec” or “fast” electric bicycles. These e-bikes can reach speeds of 28 mph, but are full pedal-assist and need human power to engage the motor. In Europe, these bicycles do have some additional restrictions and limitations compared to more standard e-bikes. In the US, there is confusion around the classification of these bicycles.
- Dozza, M., Werneke, J., & Mackenzie, M. (2013). e-BikeSAFE: A naturalistic cycling study to understand how electrical bicycles change cycling behaviour and influence safety. In International Cycling Safety Conference (pp. 1–10). Helmond, The Netherlands. Retrieved from http://www.icsc2013.com/papers/dozza2013_ebikestudy naturalistic biking.pdf
- Langford, B. (2013). A comparative health and safety analysis of electric-assist and regular bicycles in an on-campus bicycle sharing system. Doctoral dissertation at the University of Tennessee, Knoxville. Retrieved from http://trace.tennessee.edu/utk_graddiss/2445/
- MacArthur, J., Dill, J., and Person, M. Electric Bikes in the North America: Results from an online survey. Transportation Research Record: Journal of the Transportation Research Board, TRR 2468, Transportation Research Board of the National Academies, Washington, D.C. 2015, IN PRESS.
- MacArthur, J., and Kobel, N. Regulations of e-bikes in North America: A policy review (NITC-RR-564). National Institute for Transportation and Communities. http://nitc.us/research/project/564/ Portland, 2014.
- Opiela, Kenneth S., Snehamay Khasnabis, and Tapan K. Datta, "Determination of the Characteristics of Bicycle Traffic at Urban Intersections," Transportation Research Record 743, 1980.