The safety of electric bicycles. Paul Schepers

Transcription

1 The safety of electric bicycles Paul Schepers

2 Content Context Cycling safety in general The safety of electric bicycles 2 RWS UNCLASS

3 Introduction Definition electric bicycle according to European legislation: - pedal assistance up to 25 km/h - same traffic rules as for cyclists Abbreviations: - Electric Bicycle: EB - Classic Bicycle: CB 3 RWS UNCLASS

4 EB sales in Europe EB sales Europe Fishman, E., & Cherry, C. (2016). E-bikes in the Mainstream: Reviewing a Decade of Research. Transport Reviews, 36(1), Fishman, E., & Cherry, C. (2016). E-bikes in the Mainstream: 4 RWS UNCLASS Reviewing a Decade of Research. Transport Reviews, 36(1),

5 Sales share (%) of EBs Sales share of electric bicycles in the Netherlands (new bicycles) Source: BOVAG: 5 RWS UNCLASS

6 Use of EBs in the Netherlands Distance travelled by EB by age (2014) EB trips are about 50% longer than CB trips; EB users cycle around 50% more km than CB users Most km are by the elderly but the average age of EB users is decreasing KiM, Mobiliteitsbeeld: Van Boggelen, et al., Feiten over de elektrische fiets (Facts about the electrically assisted bicycle). Fietsberaad, Utrecht. Schepers, P., Risico's van elektrische fietsen en fietsers. Delft:. 6 RWS UNCLASS

7 Bicycle use (total: CB+EB) under and above 50 years of age (index, 1993=100) years Source: Statistics Netherlands, National Travel Survey 7 RWS UNCLASS

8 Cycling safety 8 RWS UNCLASS

9 Crash types Bicycle crash type Crash without motor vehicle: single-bicycle crash (fall or obstacle collision), bicyclebicycle, bicycle-pedestrian Bicycle motor vehicle crash (including bicycle-moped) Share serious injuries 2 Share fatalities 1 76% 11% 24% 89% Total 100% 100% 1 Source: Cognos-SWOV 2 Source: medical registrations 9 RWS UNCLASS

10 Cyclist fatalities Share of fatalities according to causes of death statistics With motor vehicles Without motor vehicles Schepers, P., et al (2016). Bicycle fatalities: Trends in crashes with and without motor vehicles in The Netherlands. Transportation Research Part F, In press. 10 RWS UNCLASS The safety of electricbicycles

11 Share of severely injured cyclists (%) Share of single-bicycle crashes (requiring hospitalization) in 11 countries having hospital data EB Switzerland: 83% (N=23) Share of all severely injured traffic casualties (%) Schepers, P., et al (2014). An international review of the frequency of single-bicycle crashes (SBCs) and their relation to bicycle modal share. Injury prevention, injuryprev Papoutsi, S., et al. (2014). E-bike injuries: Experience from an urban emergency department A retrospective study from Switzerland. Emergency Medicine International, RWS UNCLASS

12 Single-bicycle crashes are an important problem Infrastructure related, about half of all crashes Course mistake Slippery or poor road surface Cyclist related (some 45%) Low speeds, primarily while (dis)mounting Baggage against the front wheel or in front wheel spokes Braking or steering mistakes Bicycle malfunction (5%) Other (12%) e.g. external forces such as a gust of wind or dog running against the front wheel 12 RWS UNCLASS

13 Examples infrastructure 13 RWS UNCLASS

14 Examples infrastructure 14 RWS UNCLASS

15 Safety of EBs and EB users Exposure: more kilometres among older people, who are more susceptible to injuries in the event of a crash Risk: many hypotheses that have yet to be tested General: Much of the research on EB safety is from Asia EBs are beginning to reach sufficient levels of market penetration for conducting safety research in Europe Fishman, E., & Cherry, C. (2016). E-bikes in the Mainstream: Reviewing a Decade of Research. Transport Reviews, 36(1), RWS UNCLASS

16 Hypotheses Risk and speed (1) EB users are more at risk due to an increased speed Netherlands: Fietsberaad: average EB speed 1 km/h higher (19 km/h vs 18 km/h) An experiment by SWOV suggests the difference is 2 to 4 km/h when comparing EB and CB use for the same user Other countries: Germany: average EB speed 2 km/h higher US, Tennesee: average EB speed 3 km/h higher Twisk, et al., Gedrag op elektrische en gewone fietsen vergeleken. Boele-Vos, et al, Effect of physical workload on mental workload of cyclists and implications for safety of electrically assisted bicycles. ICSC Van Boggelen, et al., Feiten over de elektrische fiets (Facts about the electrically assisted bicycle). Fietsberaad, Utrecht. Schleinitz et al., Pedelec-naturalistic cycling study. Berlin: GDV UdV; Langford, et al, Risky riding: naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders. Accident Analysis & Prevention, 82, RWS UNCLASS

17 Hypotheses Risk and speed (2) EB users are less at risk because bicycles are unstable at low speeds The same experiment by SWOV shows an EB enables elderly to maintain a safe speed while riding uphill Boele-Vos, et al., Effect of physical workload on mental workload of cyclists and implications for safety of electrically assisted bicycles. ICSC RWS UNCLASS

18 Hypotheses vehicle related factors EB are heavier than CBs and therefore a bit more difficult to handle while (dis)mounting (also depending on where the centre of mass is located) EBs weigh 27.5 kg; 9 kg more than average CBs Front wheel traction increases the likelihood of front wheel skidding Most new EBs have rear wheel traction Van Boggelen, et al., Feiten over de elektrische fiets (Facts about the electrically assisted bicycle). Fietsberaad, Utrecht. 18 RWS UNCLASS

19 Hypotheses Personal factors Compared to CB users, EB users: Have a higher BMI: 27 compare to 25 for CB users Report more physical complaints These differences remain significant after controlling for age and gender Learning effect: someone who takes up cycling because of the availability of EBs may be relatively untrained / unfit Pedal support helps to prevent tiredness during a trip which may also support EB users ability to handle higher workload Schepers, P., Risico's van elektrische fietsen en fietsers. Delft:. Theurel, J., et al., Physiological and cognitive responses when riding an electrically assisted bicycle versus a classical bicycle. Ergonomics, 55(7), RWS UNCLASS

20 Observational research Germany, naturalistic study using video and speed sensor data: similar numbers of Safety Critical Events among EB and CB users (49 EB users; 31 CB users) Tennessee, naturalistic GPS/GIS-based safety study (bike share): EB and CB riders behave very similarly at traffic control devices, violating at about equal rates Schleinitz et al., Pedelec-naturalistic cycling study. Berlin: GDV UdV; Langford, et a., Risky riding: naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders. Accident Analysis & Prevention, 82, RWS UNCLASS

21 Crash research focused on crash types VeiligheidNL and SWOV Comparison of crash types of EBs and CBs among victims treated at Emergency Departments in the Netherlands (VeiligheidNL) Results: EB users were more often involved in single-bicycle crashes, especially while mounting and dismounting This difference largely disappeared after controlling for age In-depth research by a multi-disciplinary team of researchers (SWOV). EB related factors did not play an important role in the prototypical scenario s found in the study Only the high mass and high position of the battery was mentioned for single-bicycle crashes at low speed Kruijer, et al., Fietsongevallen in Nederland (Bicycle Crashes in the Netherlands). VeiligheidNL, Amsterdam. Davidse, et al., Fietsongevallen van50+ ers. Den Haag: SWOV. 21 RWS UNCLASS

22 Crash research focused on crash risk VeiligheidNL, TNS Nipo, The same sample of crash victims treated at the emergency department were combined with a sample of cyclists without recent crash history 22 RWS UNCLASS

23 Association between bicycle type and involvement in crashes for which treatment at an ED is needed Controlled for: gender, age, and bicycle use 23 RWS UNCLASS

24 Association between bicycle type and injury severity (hospitalization required after an ED treatment) Controlled for: gender, age, and bicycle use, and role of health condition in the crash, speed 24 RWS UNCLASS

25 Other studies focused on severity Germany: comparison of accident data of 30 EB users and 4,514 CB users in (GIDAS) Results: injuries did not occur more often or more serious in EB accidents Switzerland: police recorded crashes in Results: EB accidents are more serious than CB accidents; the differences in accident severity are primarily due to age Otte, et al., Pedelecs im Unfallgeschehen und Vergleich zu konventionellen nicht motorisierten Zweiraedern. VKU Verkehrsunfall und Fahrzeugtechnik, 52(2). Scaramuzza, et al E-Bikes im Strassenverkehr Sicherheitsanalyse. Bern: bfu-beratungsstelle für Unfallverhütung. 25 RWS UNCLASS

26 Conclusions The availability of the electric bicycle has encouraged cycling (especially) among the elderly leading to increased bicycle use within the most vulnerable group (exposure) Use of electric bicycles is associated with an increased risk to be treated at an emergency department due to a crash, but EB crashes do not seem to be more severe than CB crashes More research is needed to examine the most likely explanation for risk differences, e.g. Experimental research, e.g. to determine to what degree front wheel traction is a problem Crash research with better control for vehicle and person factors 26 RWS UNCLASS

27 Recommendations Examine technical improvements and new safety features: A descending saddle for safe and comfortable dismounting ( Sofiets developed by University of Twente, Roessingh and INDES) Steer assist (concept developed by TU Delft) RWS UNCLASS

28 Questions 28 RWS UNCLASS