Reconstructing Bicycle vs. Motor Vehicle Accidents

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Reconstructing Bicycle vs. Motor Vehicle Accidents

On the Scene E-Newsletter, Edition 156, March 20, 2012

bike car_000014362314smallBicycles and cars have been bumping into each other for quite some time.  The first automobile crash in the United States occurred in New York City in 1896, when a motor vehicle collided with and killed a bicyclist.  Over a hundred years later, it’s still happening at a fairly high rate.  784, 725, 629, 665, 732, and 693 cyclists died per year in 2005, 2004, 2003, 2002, 2001, and 2000 respectively.  The 761 cyclists killed in 1996 accounted for 2% of traffic fatalities, and the 59,000 cyclists injured made up 2% of all traffic injuries.

When a 3,000+ lb vehicle, made of metal and steel, strikes a human body riding a 30 lb or less bicycle, no matter the speed of either vehicle, the consequences are usually bad, and often tragic, and if so, reconstructing the accident is usually a necessity.  Investigating and reconstructing motor vehicle accidents is a mature industry.  There are very strict guidelines involving the operation of cars in the United States.  Billions of dollars of research have gone into safety studies, research, and development of motor vehicles.  For the most part, cars behave in a very predictable manner.  There are accident reconstructionists with decades of experience studying car crashes with hundreds of accident investigations under their belt.  Are these experts qualified to reconstruct an accident involving a bicyclist?  Unless these accident reconstructionists have direct experience with biking accidents, bicycle dynamics, limitations and capabilities and have actually ridden bicycles, maybe not.

Cars and trucks travel in a very foreseeable fashion.  They use roads exclusively, entering and exiting them at well-established and distinguishable access points such as ramps, driveways and other roads.  Bicycles and bicyclists are not as predictable.  They can ride on roads, they can ride on sidewalks or they can ride on the grass, gravel and dirt between the two.  When on the road, bikes may stick to the side, stay in the center of the lane or weave in between traffic, passing cars on the left or right.  Bikes can access roads by the traditional access points and angles or they can shoot off curbs from any angle, with or against traffic.  Often it seems that each individual bicyclist travels by their own modified rules of the road.

These vastly varying variables can make reconstructing bicycle accidents a skill unto itself.  The unpredictability of bicycle and bicyclists can dramatically raise the skill level needed to determine angles of impact, lines of sight and Delta-V.  When looking for an expert to reconstruct a bicycle accident, three things are most important:

1. Experience reconstructing bicycle accidents
2. Bicycle knowledge
3. The correct tools.

Experience with actual bike accidents is critical.  For all the reasons stated above, you want someone who has investigated bicycle accidents before.   Acceleration rates, stopping speeds, turning capabilities are all vastly different with bicycles than with motor vehicles and much less documented and harder to find.

We all know the expression “Like riding a bike”, but when it comes to experts, it’s not that easy.  The NHTSA estimates that the average American driver drives approximately 15,000 miles a year.  Most adults, including accident reconstructionists, have thousands of hours of driving experience.   The same cannot be said for bike riding.  Many adults, including accident reconstructionists, can go years between times they sat on a bike.  You need an engineer that can put themselves “on the bike”, just like they “put themselves in the car” in traditional accident reconstructions.  They need to understand the options the bicyclist had and the decisions they made.

Finally, the accident reconstructionist has to have the right tools.  Visibility is often a critical factor when reconstructing the bicycle accidents.   Trying to determine who could see whom, and when is a completely different matter with bicycles, than it is with cars.   Cars are standard shapes and sizes, traveling expected paths, and most importantly, other drivers expect to see them, and therefore, are looking for them.  The same is not true with bicycles and  Line of Sight and Conspicuity become very important.  When reconstructing bike accidents, having an animation tool that can determine and then demonstrate what and when could be seen during the accident is imperative. To find out more about how CED engineers follow the evidence and perform forensic engineering, call 800.780.4221 today to speak with an engineer about your case or claim.