Bicycle Lights - an impact study Troels Andersen, Projekt Cykelby (Cycling City Project), Municipality of Odense Harry Lahrmann, Traffic Research Group, Aalborg University Jens Christian Overgaard Madsen, Traffic Research Group, Aalborg University

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 2 Aim  To study how the mounting of a driving light on a bicycle affects the cyclists’ traffic safety and their sense of security

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 3 The Light  Two diodes  Power provided by induction coil  Power is induced every time two magnets placed on the wheel spokes pass the coil  No on/off switch  Negligible friction

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 4 Background  1 October 1990: vehicles are required to use driving lights, also outside the lighting-up time.  The compulsory driving-light rule has had a positive effect on the incidence of car accidents  2002: a new type of bicycle light is presented to Odense Cykelby and the Traffic Research Group for an assessment of whether it may used as a bicycle light.  2004: the Road Safety and Transport Agency grants an exemption for an experiment  Autumn 2004: a large-scale experiment is launched as part of Odense Cykelby, scheduled to start on 1 November 2004.

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 5 The Light  You don’t forget your lights  You avoid dead batteries  [If used by all cyclists in Denmark??,] the lights would spare the environment for the disposal of more than 20,000 batteries a year  Better traffic safety?

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 6 Impact Studies Implementeringsår Effekt

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 7 Experiment Design  Clinical epidemiology –Case-control study –Follow-up study  Comparative accident analysis comparing test group and control group for one year  Design-based results from ‘CykelBus’ter Project’ in Århus  2,000 participants in test group  2,000 participants in control group  Follow the occurrence of accidents in the two groups every other month from 1 Nov – 31 Oct

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 8 Recruitment  Commenced after the summer school holidays in 2004  Newspapers  Local radio  Local TV  Odense Cykelby’s website  Letter to children in all classes of local secondary schools in the Municipality of Odense.

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 9 Potential Participants  Men, women and children from pre-school class and above (6 yrs and older)  Resident of the Municipality of Odense  Own a bicycle  Preferably a frequent bicycle-user  Has Internet access

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 10 Web-based Questionnaires  Inexpensive  Data processing  Reminder procedure easy to carry out  Conditional process  Failure to reply

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 11 Participation  More than 18,000 people register before the registration deadline!

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 12 Recruitment Form  Name  Gender  Age  Car ownership  Cycling age  Cycling frequency  Purpose of bicycle trips  Address  Postcode

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 13 Selection  Household participation  Random selection  Control  Stratified, random selection  1st recruitment  Random selection  Control  2nd recruitment

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 14 Participants  Test group: 1,845 had lights mounted on 1 November 2005  Control group: 2,000 people were willing to participate in the control group

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 15 Participants

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 16 Acceptance!  Test group: use the new driving lights and cycle as usual  Control group: cycle as usual  Everyone: fill in questionnaires every other month  In return: –Test group: receives the new driving lights, mounted by 1 November at the latest –Control group: receives the driving lights at the end of the experiment (31 October 2005)

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 17 Timeline  August – September 2004: recruitment period  Early October 2004: selection  Mid to late 2004: light distribution and mounting  1 November 2004: the experiment begins  Mid-November 2004: questionnaire test  Early January 2005: questionnaire, November – December 2004  Early March 2005: questionnaire, January – February 2005  Early May 2005: questionnaire, March – April 2005  Early July 2005: questionnaire, May – June 2005  Early September 2005: questionnaire, July – August 2005  Early November 2005: questionnaire, September – October 2005  31 October 2005: the experiment ends

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 18 Timeline  August – September 2004: recruitment period  Early October 2004: selection  Mid-late 2004: distribution and mounting of lamps  1 November 2004: the experiment begins  Mid-November 2004: questionnaire test  Early January 2005: questionnaire, November – December 2004  Early March 2005: questionnaire, January – February 2005  Early May 2005: questionnaire, March – April 2005  Early July 2005: questionnaire, May – June 2005  Early September 2005: July – August 2005  Early November 2005: September – October 2005  31 October 2005: the experiment ends

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 19 Questionnaire  s with link to questionnaire received at the beginning of the month  Reminders are sent approximately 14 days later  If a participant fails to respond, he/she is theoretically out of the experiment => he/she must return the light.

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 20 Spørgeskema

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 21

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 22

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 23

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 24

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 25

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 26

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 27

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 28

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 29

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 30

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 31

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 32 Response Ratios  Test group: 1,845 had lights mounted as of 1 November 2005  Control group: 2,000 people were willing to participate in the control group Test Group Control Group FormRepliesActive%RepliesActive% 1.1,7741, %1,9182, % 2.1,7421, %1,8781, % 3.1,7191, %1,8271, %

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 33 Accidents ”In the following, we kindly ask you to tell us about any accidents in which you have been involved in the Municipality of Odense from 1 May 2005 to 30 June We should like to point out that you should only describe accidents involving you personally as a cyclist and which occurred in the Municipality of Odense from 1 May 2005 to 30 May Cycling accidents include accidents where you have collided with another vehicle, cyclist or pedestrian, etc., but also solo accidents where you have had a fall on your cycle. Even if you were not hurt in the accident, please include a description of this accident anyway.”

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 34 Accidents  68 accidents reported by the test group –0.038 accidents per participant throughout the project period  95 accidents reported by the control group –0.050 accidents per participant throughout the project period Accidents012Persons Test1, ,719 Control1, ,827 Total3, ,546

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 35 Accidents  Incidence rate –Accidents per person-month Incidence rate = accident /  (person * month)  Incidence rate, test group: IR F = accidents per person-month IR F = accidents per person-month  Incidence rate, control group: IR K = accidents per person-month

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 36 Accidents  Incidence rate ratio: IRR = IR F /IR K = 0.77  95% confidence interval (95% CI (IRR)): 0.56 < 95% CI (IRR) < 1.05  Significance test: P ≈ 10%

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 37 Subsidiary Conclusion  The driving light tends to have a favourable impact on traffic safety  Of the two groups (which are generally the same in terms of demographic data, car ownership and cycle use), the accident frequency of the group using the driving light is around 20% lower than the control group  There are no significant differences in the types of accident that occur in the two groups.

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 38 InjuriesTestControl No injury 35.29% (24) 17.89% (17) Bruised 29.41% (20) 41.05% (39) Abrasion 13.24% (9) 22.11% (21) Ligament injury 5.88% (4) 4.21% (4) Fracture 1.47% (1) - (-) Concussion 1.47% (1) 1.05% (1) Other 13.24% (9) 13.68% (13)

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 39 Seriousness TestControlAll No doctor 86.76%(59)83.16%(79)84.66%(138) Doctor1.47%(1)8.42%(8)5.52%(9) Casualty ward 7.35%(5)6.32%(6)6.75%(11) Doctor 4.21%(3)2.11%(2)3.07%(5) Total100.00%(68)100.00%(95)100.00%(163)TestControlAll 0 days 86.76%(59)88.42%(84)87.73%(143) 1-6 days 7.35%(5)6.32%(6)6.75%(11) 7-14 days 2.94%(2)2.11%(2)2.45%(4) > 14 days 2.94%(2)3.16%(3)3.07%(5) Total100.00%(68)100.00%(95)100.00%(163)

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 40 Light Conditions

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 41 Number of Elements

Adjunkt Jens Christian Overgaard Madsen, Trafikforskningsgruppen, Aalborg Universitet, 42 Tryghed

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