Bike Paths and Lanes: The Case Against by Piaw Many bicycle advocacy groups advocate bike lanes or bike paths for "safety." However, the one major study on bicycle accidents [Kaplan 75], shows that bicycle paths or lanes do not reduce the number of accidents on them, but rather increase the number of accidents because bike lanes and paths conflict with the normal flow of traffic. Here's my summary of what John Forester has culled from [Kaplan 75]. Kaplan was both a cyclist and a transportation engineer, and his MS thesis was a study of the accidents incurred and experienced by various cyclists. The data in this article is applies to club cyclists. Kaplan gives accidents / millions miles for different types of roads: Table 13, [Kaplan 75] Major street: 114.2 Minor street: 104.8 Bike path 291.6 The "bike path" listing includes those bike paths that are walled off from the roadways. (Accidents on them happen because you hit other ill-behaved cyclists, dogs, people, and because the intersection between a bike path and a road is dangerous) He also separated accident rates in terms of what the purpose of cycling is for. Note that Utility cycling is by far the most dangerous, and commuting is relatively safe. My guess is that this is because utility cycling (running errands, etc) is usually done by kids. Table 11, [Kaplan 75] Type or purpose Accidents/million miles Serious A/million miles Work/School 97.7 24.4 Recreation/Touring 114.1 34.1 Utility 184.3 43.5 Exercise 100.6 28.9 Racing 115.4 25.6 Many people argue that car-overtaking-bike collisions are more serious than other forms of accidents because the injury to the bicycle is more. However, look at the following table Calculated from Table 13, [Kaplan 75] Type of Accident Serious injuries/ Ser. injuries/ Total for type Total of all Fall 0.24 0.096 Car-bike collision 0.38 0.070 Bike-bike collision 0.20 0.034 Bike-dog collision 0.34 0.026 Parked car collision 0.14 0.006 Railroad tracks 0.22 0.007 Bike-pedestrian collision 0.18 0.002 All other accidents 0.37 0.029 Kaplan adds the following note to this table. "The goodness of fit test (p=0.05) showed the percent of 'serious accidents' by crash type was not significantly different than those percentages for 'all collisions.'" This implies that car-bike collisions are not more severe than other form of accidents (like colliding with a pedestrain!). Even if his statistical caution is ignored, Kaplan's data show that while car-bike collisions are individually somewhat more injurious than plain falls, the difference is not that enormous and, in total, car-bike collisions with serious injuries are only 73% of falls with equally serious injuries. More importantly, we can look at what the riding style of the cyclist was before the car-bike collision: (These statistics are for urban areas) Table 28.4, [Forester 93] Style Percentage Entering Roadway 23 Riding on wrong side of the roadway 20 Turning or swerving from curb lane 14 Riding on sidewalk 8 Riding in correct position 38 Most accidents happen when you ignore the "normal" behavior of traffic. Note that people who turn or swerve from the curb lane do so usually because of bike lanes. For the adult urban cyclist, the most frequently occuring car-bike collisions are: Table 28.6, [Forester 93] 1. Motorist turning left 2. Signal light change 3. Motorist turning right 4. Motorist restarting from stop sign 5. Motorist exiting commercial driveway 6. Motorist overtaking unseen cyclist (mostly in darkness) 7. Motorist overtaking too closely 8. Cyclist hitting slower-moving car Anecdotal Evidence: from the club cyclists I've spoken to, most of their accidents occurred because they lost control (usually) going downhill or on slippery ground. The one car-bike collision I'd heard first hand occurred at an intersection. I'd venture to agree with the statement that 90% of car/bike collisions are caused by conditions ahead of you. Of the last 10%, 6% are caused by the cyclist swerving in front of the car, and 4% by the overtaking motorist, 2% of which was in the dark. So that means 2% of the accidents are caused by a motorist overtaking too closely. Of all the accidents a cyclist may run into, 50% are caused by simple falling off the bicycle (like when I went downhill too fast once...), 17% by car-bike collisions, 17% bike-bike collisions (including following too closely when taking pace), 8% bike-dog, and 8% all others[Forester 93]. You're much more likely to be killed by crashing into a fence than getting hit by a car. Bike lanes narrow the main road, and reduce the sweeping action that cars provide. They also give motorists and law enforcement officers an excuse to harrass bicyclists when they (we) refuse to use dangerous bike lanes. I shall now point to specific examples in the Silicon Valley area where bike lanes diminish the usefulness of a road for bicyclists. Cox Avenue in Saratoga in the rainy season gets cluttered up with pine needles and mud in the bike lane, forcing bicyclists to use the main road. The reason the bike lane is muddy is because cars do not get on it and sweep it clean of debris (which is why the main road is clear). Of course, the moment you get into the main lane to avoid the debris and slippery conditions, you would get honked at or screamed at to "clear out of the road." The same conditions apply to Saratoga Avenue near the Highway 85 construction. Another example is the bike lane in Los Altos on Fremont Avenue. This lane weaves in between trees in and out of the traffic lane, bringing the cyclist abruptly into and out of view of passing motorists. However, any attempt to merge into the main lane instead of weaving into and out of traffic brings a torrent of abuse from unknowledgeable motorists who think that you should be off *their* road. Most experienced cyclists ignore this, but novice cyclists would either take the more dangerous route (and if they get hit they conclude that bicycling is a dangerous sport!) or receive abuse for proper riding. So when considering bike lanes, which can only help with that 2% of 17% of all bicycle accidents, don't you think that the money can be better spent on the education of cyclists? How about an Effective Cycling class? Or maybe it could be used to build a bike-pedestrain bridge? Or to educate legislators or motorists? Bike lanes don't require less skill to ride safely on them, they require *more* skill to ride safely on them. There is no substitute for proper education, experience, and training. Let's stop the myth that bicyclists don't belong to roads. We do, and have all the rights (and responsibilities) that go with being a road user. "Separate but equal" facilities are anything but equal. Bibliography: Here's the full reference for the study of accidents: [Kaplan 76] Kaplan, Jerrold A.; Characteristics of the Regular Adult Bicycle User; MS thesis U of Maryland, 1975. A copy of this report may be obtained from: National Technical Information Service Springfield, Virginia, 22151 Other data on cyclists and accidents can be gotten from: Kenneth Cross and Gary Fisher, A study of Bicycle/Motor Vehicle Accidents: Identification of Problem Types and CounterMeasure Approaches (NHTSA, 1977). This study showed that cyclists do learn from experience how to avoid car-bike collisions. John Forester, Bicycle Transportation, MIT Press, 1983 This contains a lot of information on the engineering of bikeways, and data on accidents and how road conditions cause them. [Forester 93] John Forester, Effective Cycling, MIT Press, 1984, 1993. This is *the* book on riding in traffic. I wish I had this book 3 years ago when I started my 10 mile commute to work. It would have saved me several hairy incidents involving wrong way riding, running stop lights, and such.