1. An International Survey of Lane Splitting Research
Jim Ouellet
Motorcycle Accident Analysis
Playa del Rey, CA 90293
State Motorcycle Safety Administrators
National Motorcycle Training Summit
Sacramento, California
September 12-16, 2018

2. Motorcycle Lane Splitting Was Banned in 49 States without Evidence that It’s Dangerous -- or Not
In California, it has never been banned nor been explicitly legal.

3. 1. Motorcycle Lane Splitting on California Freeways, 2011
Two parts:
A survey of lane splitting on L.A. freeways in 2011
A review a Hurt study data on L.A. freeway crashes that involved lane splitting motorcycles and those not splitting lanes
Ouellet JV, Motorcycle Lane-Splitting on California Freeways Transportation Research Board 2012 Annual Meeting, Washington DC January 22-26, 2012, Paper No

4. Even Police Do It

5. Caltrans Freeway Cameras Show Live Video + Traffic Speeds

6. Percent of Motorcycles Lane Splitting as a Function of Traffic Speed, Rush Hours

7. Motorcycle Position in Roadway, Rush Hour Observations in 2011

8. Motorcycle and OV Precrash Speeds in Moderate-Heavy Freeway Traffic

9. Distribution of 60 Hurt Study Freeway Crashes

10. Hurt Study Comparison of Lane Splitting in Accident and Exposure Groups.

11. Hurt Study, Accident Configuration by Other Vehicle Precrash Motion
(Lane splitting MCs in parentheses)
Other Vehicle (OV) Precrash Motion
Total
Moving Straight
Overtaking
Slowing
Stopped
Lane change
MC strikes OV rear end 3 2 1 6
Same direction sideswipe
(1)
(3)
(4)
MC fell or ran off road to avoid OV
Other MC-OV crashes 1* 5 15

12. Rider Medical Treatment, Lane Splitting or Not, Freeway, Moderate - Heavy Traffic

13. 2. Rice et al. Method
CHP and some police agencies filled out a special online supplement to police reports of motorcycle accidents.
5,969 reports, 997 (17%) were lane splitting when they crashed.

14. 2. Rice et al., Lane Splitting in California (2015)
Rice T, Troszak L and Erhardt T; (2015) Motorcycle Lane-splitting and Safety in California
Safe Transportation Research & Education Center, University of California, Berkeley

15. California Lane Splitting Study Injury Location by Lane Splitting
Rice T, Troszak L and Erhardt T; (2015) Motorcycle Lane-splitting and Safety in California
Safe Transportation Research & Education Center, University of California, Berkeley

16. 2. Riders who were lane-splitting were more likely to:
Be riding weekdays and commute hours
Wear a better helmet
Be alcohol-free
Have less severe injuries or be killed
Be riding without a passenger
Rice T, Troszak L and Erhardt T; (2015) Motorcycle Lane-splitting and Safety in California
Safe Transportation Research & Education Center, University of California, Berkeley

17. 2. Lane Splitting, Speed and Injury Severity
Injuries were comparable for traffic speeds up to 50 mph
Injuries were comparable if the speed differential was under 15 mph.
Rice T, Troszak L and Erhardt T; (2015) Motorcycle Lane-splitting and Safety in California
Safe Transportation Research & Education Center, University of California, Berkeley

18. 2. Berkeley Lane Splitting Study Conclusions
“Lane-splitting appears to be a relatively safe motorcycle riding strategy if done in traffic moving at 50 MPH or less and if motorcyclists do not exceed the speed of other vehicles by more than 15 MPH. A significant number of motorcyclists lane-split in fast-moving traffic or at excessive speed differentials.”
Rice T, Troszak L and Erhardt T; (2015) Motorcycle Lane-splitting and Safety in California
Safe Transportation Research & Education Center, University of California, Berkeley

19. 3. Evaluating the New Traffic Filter Rule for Motorcyclists
Heike Martensen
Julien Leblud
Philip Temmerman
Belgian Road Safety Institute
Presented at 2016 IfZ Conference, Cologne

20. 3. Lane Splitting in Belgium Before and After Legalization
“Traffic filtering” was legalized in Belgium in 2011, within limits:
Motorcycle top speed < 30 mph,
Speed differential < 12 mph
Permitted on all multi-lane roads but it mostly occurred on motorways during rush hour.
2.6% of motorcycle crashes involved multi-vehicle motorway crashes.

21. 3. Lane Splitting in Belgium Before and After Legalization
Only 2.6% of motorcycle crashes were motorcycle-car on a motorway.
No way to identify lane-splitting crashes, so they compared motorway motorcycle-solo (MS) to motorway motorcycle-car (MC) crashes.

22. 3. Lane Splitting in Belgium Before and After 2011 Legalization
After lane-splitting was legalized motorcycle-solo motorway crashes declined to 65% of pre-legalization levels.
Motorcycle-car motorway crashes declined to 74% of pre-legalization levels.
The difference was not statistically significant.
The effect of legalization on the overall crash population was trivial.

23. 4. Motorcycle Lane Filtering Trial, Sydney Australia, 2014
“Lane Filtering” (overtaking between lanes of stopped or slow moving vehicles) was allowed on a 2 month trial basis on the surface streets of Sydney’s Central Business District.
Lane splitting (reckless passing between lanes) was and remains banned.
Rider behavior was monitored by video.
Police reported seeing occasional “curb sneaking” and passing next to parked cars.
Mulvihill CM, Salmon PM & Filtness, A., Lenné M, Walker GH, Cornelissen M & Young, KL;
Lane filtering and situation awareness in motorcyclists: an on-road proof of concept study, Proceedings of the 2013 Australasian Road Safety Research, Policing & Education Conference, August 28-30, 2013, Brisbane, Queensland

24. 4. Results of Sydney Lane Filtering Trial
“Lane filtering was a relatively low risk riding activity for motorcyclists under the conditions of the trial.”
No lane filtering or lane-splitting crashes
Riders felt their trip time was shortened
No effect of overall traffic congestion
Worries about pedestrian safety

25. 5. Lane Filtering on Urban Streets in Marseilles, France
Examined lane filtering and crash data Monday-Saturday, 6 a.m. – 10 p.m. on 14 different road segments.
Included riding in opposing lanes, in bus lanes and what we’d call lane splitting.
Counted motorcycles, scooters and mopeds.
Clabaux N, Founier J-Y, Michel J-E; (2017) Powered two-wheeler riders’ risk of crashes associated with filtering on urban roads;
Traffic Injury Prevention, 18 (2)

26. 5. Three Types of “Lane Filtering” in Marseilles
In Opposing Lane
In Bus-Only Lane
Between Lanes

27. 5. Principal Findings - Marseilles
Crash risk (mopeds + light + heavy motorcycles) and all types of filtering ~4 times as great for filtering motorcycles
For “heavy” (>125 cc) motorcycles splitting between lanes, the crash risk was 2.75 times as great as for riders not splitting lanes.

28. Marseilles – Methodology Issues
“Heavy” motorcycles splitting lanes had only 4 crashes in 3 years.
Exposure calculation method assumes that motorcycle was filtering or not filtering the entire length of the road segment on which it was observed. Road segment length was part of the exposure calculation.
All data from 6 am-10 pm, not just rush hours.
No description of collision configurations or cause, only whether a crash occurred.
Crash data from ; exposure data from 2013.

29. Lane Splitting Compared to Not Splitting
Summary of Findings for Different Studies
Study
Crash Risk
Injury Severity
Comments
Ouellet, Hurt Study Los Angeles,
Possibly lower
No data
Too small a sample for any certainty
Rice et al., California,
Lower injury severity
Huge sample of enhanced police data
Sydney, Australia
Mulvihill et al., 2013
No change
Brief sampling period
Martensen et al., 2016
Belgium
Unable to count lane-splitting directly
Clabaux et al, 2017
Marseilles, France
Increase, 2.75x
Sampling during non-rush hours; Questionable calculation method

30. Thank You