The blog Lovely Bicycle has a great article on a concept she calls the Mary Poppins effect
http://lovelybike.blogspot.com/2011/01/mary-poppins-effect.html. The Mary Poppins effect states that drivers will give more room to a young women riding a traditional bike with no helmet and long flowing skirt than to the same rider wearing a helmet, tight clothes on a race oriented bike. The author developed this concept when she noticed that some drivers treat her differently depending on what she is wearing and what bike she is riding. Reading the comment section of the blog, you see that several people have also confirmed the effect while.
The Merry Poppins Effect
At this point it is difficult to identify which of the factors – gender, attire or bike type have the greatest impact but there is one comment from a man that may be helpful. He states that he has observed the same effect when he wears a coat that flaps in the wind. The flapping coat and skirt may cause the bike rider to appear bigger than they actually are causing drivers to give them more room. Another theory is that drivers fear that the coat or skirt may catch on their car window and they give the biker room out of their own interests. A third theory states that the flapping causes some confusion and unpredictability.
A road bike however is the exact opposite. When you see a biker in spandex on a road bike, they ride with precision and consistency. A driver is more likely to come closer to them because the bike almost appears stationary next to the car.
Another thing to notice is that a road bike has a triangular shape with the thinnest part of the bike in the back and the widest in the front. Drivers may see the back tire and assume the rest of the bike is the same size.
Top view of a bike. Notice the bike is thinnest in the back.
Bike Safe
http://bicyclesafe.com/ shows one example of how a rider addresses this problem by using a foam pool toy to show the maximum width of their bike.
The noodle is the same size as the widest part of the bike.
If there truly is a Mary Poppins Effect, how can that concept be used to improve bike safety?
The first method is to modify bike clothes. One way to do this is to add small ribbons to the sleaves of a bike jersey. As the rider pedals, the ribbons would dance in the air and create a confusing image that should help create the Mary Poppins effect.
Streamers create confusion causing drivers to give more room.
For road racers like the one above, this ribbon would have to be small to help reduce aerodynamic drag. One option for bike commuters who do not wear tight fitting clothes would be to have a coat that has tails that are designed to flap in the wind. Remember the goal is to create confusion and make the rider look like they take up more space. Betabrand
http://www.betabrand.com/ is one company that could help produce this type of clothing for daily commuters.
Another method would be to add streamers to a stick on the bike itself. Care should be taken that they are not too long so they would get caught in the spokes or brakes. Again, as the rider pedals, the streamers would fly in the breeze erratically creating confusion about the riders actual size and location causing drivers to give more room.
Of course, this does not mean you can ride recklessly. When the morning radio states that there is an accident involving car vs motorcycle. There is no doubt about who wins. The motorcyclist goes to the hospital and the car my need a paint touch up. Bicyclists suffer the same fate.
By modifying clothing to create some sort of visual confusion, bicycle clothing manufacturers can reduce the possibility of a collision between a car and the rider. The visual confusion will cause drivers to keep a greater distance between their car and the bike rider which makes for a safer bike riding expereince.
