Motorcycles & lane splittingHeike Martensen, Julien Leblud, & Freya Slootmans

Belgian Road Safety Institute

‣ Lane splitting & traffic filtering

‣ Allowed in Belgium since 2011 if

‣ Motorcylist passes between 2nd & 3rd lane (motorway)

‣ Max speed < 50 km/h

‣ Speed difference with other vehicles < 20 km/h

Background

Traffic filtering motorcyclists: speed infringements

65%

37%

35%

9%

19%

35%

0%

20%

40%

60%

80%

100%

120%

Urban roads Motorways

>30 km/h

10 - 30 km/h

<10 km/h

correct speed

‣ Urban roads: speed regulations for traffic filtering are respected

‣ Motorways: speed limitations are routinely violated

‣ Did the change in regulation for traffic filtering have an impact on accidentology?

‣ Focus on motorways

Conclusion and further question?

General trend in motorcycle accidentology

2000

2200

2400

2600

2800

3000

3200

3400

3600

3800

4000

Number of injury accidents involving motorcyclists,

Belgium 2005 - 20013

‣ Belgian accident data: impossible to identify traffic filtering

‣ Assumptions: traffic filtering accidents more present in

‣ Multi vehicle accidents (as compared to single vehicle)

‣ Rush-hour accidents (as compared to other times)

‣ Focus on motorways.

5

Method

6

MethodTraffic volume Rider training Equipment

Sensibilisation …

Traffic filtering

‣ Critical accidents

‣ Influenced by traffic filtering

‣ Multivehicle accidents

‣ Rush-hour accidents

‣ Neutral accidents

‣ Not influenced by traffic filtering

‣ Single vehicle accidents

‣ Off-peak accidents

7

Distribution of motorcycle accidents

Before

Motorways SV

Motorways MV

Rural SV

Rural MV

Urban SV

Urban MV

After

Before legalizing traffic filtering: 2009-2010

After legalizing traffic filtering: 2012-2013

‣ Distribution of motorcycle accidents did not change after legalizing traffic filtering.

‣ Only a small proportion of motorycle accidents take place on motorways.

8

Distribution of motorcycle accidents

‣ Comparing critical (c) to non-critical (nc) accidents:

‣ Odds ratio

OR =

n(crit)aftern(crit)before

n(nc)aftern(nc)before

‣ SE =

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�

� ���� ��� ��+

�

� �� �����+

�

� �� ��� ��

‣ !" = #$ ± 1.96*+

9

Method

0

1

2

Odds ratio

Increasedrisk

Decreasedrisk

Multivehicle vs single vehicle accidents on motorways

‣ Test before after:

‣ OR=1,14; CI-=0,83; CI+=1,4

‣ Multivehicle & single vehicle accidents both reduced

‣ No significant difference in development

Multivehicle vs single vehicle accidents

0

1

2

Odds ratio

Increasedrisk

Decreasedrisk

Rush-hour vs off peak accidents (MV on motorways)

‣ Rush-hour:

‣ 6:00 – 9:00

‣ 16:00 – 18:00

‣ Off-peak

‣ All other

‣ Test before after:

‣ OR=1,1; CI-=0,6; CI+=1,6

‣ Off-peak and rush-hour crashes both reduced

‣ No significant difference in development

Rush-hour vs. off-peak accidents (MV on motorways)

0

1

2

Odds ratio

Increasedrisk

Decreasedrisk

Conclusion

• General decrease in motorcycle accidents since 2011 in Belgium.

• No specific decrease or lack of decrease for accidents critical to traffic filtering:

• Multivehicle accidents

• Rush-hour accidents

• Critical and non-critical accidents developed in the same way.

• Legalizing lane splitting does not seem to affect accidentology.

Disclaimer

‣ Countries differ … so does lane-splitting.

‣ These results are from Belgium.

‣ Lane-splitting is common but not ubiquitous.

‣ Transferability to other countries needs to be established.

Motorcyclists lane splitting in Bangkok, Thailand.Roland Dobbins, Singapore

Heike MartensenBelgian Road Safety Instituteheike.martensen@bivv.be