Tuesday, May 15, 2012

Hit From Behind?

Interesting post and letter from LAB below on BikeDelaware. We need good numbers. In an age of rampant driver distraction, it would not surprise me if the relative proportion of various crash types has changed. Does anyone have a link to modern numbers?

Part of the problem with the letter below is the LAB mixes apples and oranges. The one in four figure is for fatal crashes, whereas the low percentage of rear end crashes is when compared to all crashes.

One could probably argue with some confidence that bicyclists, including myself, are far more interested in mitigating the kinds of crashes that are going to put me six feet under or in an ICU than the type of crash that merely has me nursing some road rash, picking up the bike, and going home. Therefore, yes, I think we really want to know if the percentage of rear end crashes of all types (fatal or non-fatal) are going up, because these are indeed some pretty lethal crashes.

Are more cyclists getting hit from behind than ever before?

Bike Delaware includes a copy of page three of a letter it says it got from the League:



Little Jimmy said...

Nice post for Bike to Work Day....

Anonymous said...

That's why, as a commuter, a helmet or eyeglass mirror is essential.

Steve A said...

As with many things, getting "hit from behind" can mean many different things. For example, a curb-hugging cyclist that gets sideswiped is "hit from behind" as is a cyclist controlling his lane as he crosses the Fahey Bridge. I think the latter is rare compared to the former, so I'm reluctant to say that LAB Bike Ed principles are invalid based on raw data that doesn't distinguish between one situation and a quite different one.

Steve A said...

As my post indicated, the second situation "could have been me."

Khal said...

Responding to Steve, I think we need modern numbers and a clear breakdown between sideswipe crashes and clearly "hit from behind" (i.e., the 2009 West Jemez Road crash) incidents.

I would also like to see whether in total, cyclists riding "vehicularly" are still safer than those who are riding in other ways. The premise of vehicular cycling is that a cyclist fares best when riding as a vehicle operator in traffic. The underlying premise is that this reduces the risk by making the cyclist predictable and visible. All good things. It also assumes that this behavior minimizes errors capable of hurting the cyclist. But if one were to dissect the numbers, does this hypothesis hold up to scrutiny? What if distracted driving, for example, has so skewed driver behavior that this premise falls apart?

I realize I am pissing on the Holy Cross of Vehicular Cycling here, but someone has to do it and it might as well be a Vehicular Cyclist. My wish is for a well funded NIH or NHTSA study done by well qualified, unbiased people who could once and for all look at modern crash numbers and dissect them.

Anonymous said...

I fear the modern day distracted driver has skewed behavior. The distracted driver takes a quick look down the road not seeing the cyclist and then continues to text, or whatever, while plowing the cyclist from behind or drifting to the side into the bike lane, shoulder, etc. The number of drivers who are driving like this is higher than you think. This is truly frightening, and not just for cyclists.


MikeOnBike said...

If distracted driving is going up, should we see more motorcyclists hit square from behind?

In addition to "sideswipe" and "square-on" there's also "drift". A motorist drifts out of their lane, hitting somebody in the adjacent lane, or bike lane, or shoulder. Some of those might resemble sideswipes. Could more distractions cause more drift-style sideswipes of cyclists in bike lanes and shoulders?

If I'm squarely in the center of a narrow lane, I generally see one of two reactions:

1. Most motorists realize well ahead of time that they have to change lanes, and do so without any inconvenience, friction, or delay.

2. The occasional motorist catches up to me then slows to my speed. Eventually they realize they're following a cyclist and eventually a gap opens up so they can change lanes to pass me. My hunch is that's what distracted driving typically looks like when a cyclist is being vehicular.

Khal said...

Motorcyclists are generally riding at the speed of traffic, so I would suspect they would not be the beneficiaries of rear-end crashes between vehicles with serious differences in speed except when stopping for traffic. Actually, in Motorcycle Safety Foundation courses, they teach that as a concern. Some motorcyclists sit with the bike in gear and the clutch pulled in. I was nearly hit that way (back in 1979) by a distracted driver when sitting at a red light on my Honda CB450. It was unnerving, but I was alert enough to traffic behind me that I was able to accelerate out of the way.

When I am biking to work, everyone is passing me. When I am motorcycling to work, I am part of the motor vehicle flow. In that case, the overwhelming concern is what is ahead of me. We teach bicyclists similarly--the danger is ahead. Except if the change in paradigm to driver distraction changes the validity of that assumption due to drift, etc. Hence my question. Have we tested the hypothesis lately?

The vast majority of the time, motorists are not hitting cyclists. Crashes occur in those tiny fraction of cases when someone makes a mistake. Those are the cases that end up being written up and usually, not with enough information to really know what the underlying causes were.

MikeOnBike said...

I agree with you Khal, we don't have enough info. For motorcycles, I was thinking of intersections or stop-and-go traffic where a distracted driver might manage to notice a car in front of them, but not the motorcycle behind the car.

I think a basic question to ask is "what does distracted driving look like?" In my own observations, if I see somebody driving slowly or having trouble staying in their lane, or starting slowly from a green light, I can sometimes see a gadget in their hand.

Conversely, if you tried to drive your car with your eyes closed, how long could you do that without rear-ending the car in front of you, or sideswiping the car next to you? In other words, how often does a distracted driver have to look up to avoid crashing?

Also, does the field of view change for a distracted driver? Are they less aware of what's beside them? Are they less aware of what's further in the distance?

Are distracted drivers more likely to be speeding, or more likely to be slower than traffic?

Has the nature of distracted driving changed in the last couple decades? We assume there are different distractions today. Does that lead to different styles of distracted driving?

I have some hunches that being beside a distracted driver is possibly more dangerous than being in front of one.