BIKE: fact sheet on bike lanes

[Stephen Wechsler]

I found this to be a handy reference source for reliable safety studies.
Maybe you've already seen it.
   --Steve

http://www.ci.cambridge.ma.us/~CDD/envirotrans/bicycle/lanes/bikelane- 
safety.html#5



Safety Benefits  of Bike Lanes

Bike lanes help define road space, decrease the stress  level of  
bicyclists riding in traffic, encourage bicyclists to ride in the   
correct direction of travel, and signal motorists that cyclists have a  
right to  the road. Bike lanes help to better organize the flow of  
traffic and reduce the  chance that motorists will stray into cyclists’  
path of travel. 1, 2Bicyclists have stated their preference for marked   
on-street bicycle lanes in numerous surveys. 3   In addition, several  
real-time studies (where cyclists of varying abilities and  backgrounds  
ride and assess actual routes and street conditions) have found that   
cyclists are more comfortable and assess a street as having a better  
level of  service for them where there are marked bike lanes present. 4


In summary, bike lanes do the following:
support and encourage bicycling as a means of transportation
help define road space
promote a more orderly flow of traffic
encourage bicyclists to ride in the correct direction, with the flow of  
traffic
give bicyclists a clear place to be so they are not tempted to ride on  
the sidewalk
remind motorists to look for cyclists when turning or opening car doors
signal motorists that cyclists have a right to the road
reduce the chance that motorists will stray into cyclists’ path of  
travel
make it less likely that passing motorists swerve toward opposing  
traffic
decrease the stress level of bicyclists riding in traffic

Well-designed facilities encourage proper behavior and  decrease the  
likelihood of crashes. Numerous studies have shown that bicycle  lanes  
improve safety and promote proper riding behavior. .5
In 1996, over 2000 League of American Bicyclist members were surveyed  
about the crashes          (accidents) they were involved in over the  
course of the previous year. From the          information, a relative  
danger index was calculated which shows that streets          with bike  
lanes were the safest places to ride, having a significantly lower       
     crash rate then either major or minor streets without any bicycle  
facilities;          moreover, they are safer than trails and sidewalks  
as well. 6
The addition of bicycle lanes in Davis, California reduced crashes by  
31 percent .7
Bicycle lanes on a major avenue in Eugene, Oregon resulted in an  
increase in bicycle use          and a substantial reduction in the  
bicycle crash rate. The crash rate per          100,000 bike miles fell  
by almost half and the motor vehicle crash          rate also fell  
significantly .8
When the city of Corvallis, OR installed 13 miles of bicycle lanes in  
one year, the          number of bicycle crashes fel l from 40 in the  
year prior to the installation          to just 16 in the year  
afterwards, and of the 5 crashes that occurred on streets          with  
bike lanes, all involved bicyclists riding at night with no lights. 9
In Chicago, Illinois, crash severity was reduced in one study of  
marking bike lanes          in a narrow cross section where 5 foot bike  
lanes were marked next to 7 foot          parking lanes. 10
In Denmark, bicycle lanes reduced the number of bicycle crashes by 35  
percent .11  Some of the bike lanes reached risk reductions of 70 to 80  
percent .12
A comparison of crash rates of all types in major cities has shown that  
cities with higher          bicycle use have lower traffic crash rates  
of all types than cities with          lower bicycle use. 13
In a national study comparing streets with bike lanes and those  
without, several          important observations were made: 14
Wrong-way riding was significantly lower on the streets with bike lanes  
.
In approaching intersections, 15% of cyclists on streets without bike  
lanes rode          on the sidewalks, vs. 3% on the streets with bike  
lanes.
On streets with bike lanes, 81% of cyclists obeyed stop signs, vs. 55%   
         on streets without .
In Cambridge, sidewalk bicycling was cut in half after the installation  
of bicycle lanes on Mass. Ave. in Central Square. 15
Corvallis and Eugene, Oregon, cities with good bikeway networks, have  
the          highest number of riders and rider behavior is the best:   
wrong-way riding is          minimal, fewer ride on the sidewalk than  
in other Oregon cities.
In looking at comparable streets with and without bicycle lanes in  
Davis and Santa Barbara,          California, the number of cyclists  
riding on the wrong side of the street was one third as much on streets  
with bicycle lanes .

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Footnotes
David L. Harkey and J. Richard Stewart, “Evaluation of Shared-Use  
Facilities for      Bicycles and Motor Vehicles in Florida,” Florida  
Department of      Transportation, March 1996.
Cyclists are still permitted to travel in the regular vehicle travel  
lanes even when a      bike lane is present. Cyclists should signal and  
make sure they have the      attention of the people behind them before  
moving into the vehicle travel      lane from a bike lane. Motorists  
should be aware that cyclists may merge      into their lanes in front  
of them, e.g., to avoid an obstacle or to make a      left turn.
Monique Stimson, “Analysis of Commuter Bicyclist Route Choice Using  
Stated      Preference Study,” TRB, 2003.; FHWA, Development of the  
Bicycle      Compatibility Index , December 1998.
Bruce Landis et al., “Real-Time Human Perceptions: Toward a Bicycle  
Level of Service,” T ransportation      Research Record 1578; FHWA,  
Development of the Bicycle Compatibility      Index , December 1998.
Federal Highway Administration, Safety Effectiveness of Highway Design  
Features,      Volume VI, Pedestrians and Bicyclists , FHWA-RD-91-049,  
1991.
William E. Moritz, Ph.D., “Adult Bicyclists In The United States   
Characteristics And      Riding Experience In 1996,” TRB Preprint Paper  
, 1998.
Federal Highway Administration, Bicycle Safety-Related Research  
Synthesis ,      1995.
Ibid .
Ibid .
Pedestrian and Bicycle Information Center, Bike Lane Design Guide ,  
2002.
Danish Road Directorate, Safety of Cyclists in Urban Areas , 1994./li>
Jan Grubb Laursen, Nordic Experience with the Safety of Bicycling ,  
1993.
Peter Newman, Lecture presented at the Conservation Law Foundation,  
Boston, MA, January 9, 1997.
Federal Highway Administration, Bicycle Lanes versus Wide Curb Lanes:  
Operational      and Safety Findings , May 1998.
City of Cambridge data, unpublished.