Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009

Abstract

Traffic records for all bicyclist fatalities occurring in Arizona during the year 2009 were categorized and listed according to manner of collision and assignment of fault. Primary results are that 11 of 25 fatalities (44%) were determined to be the fault of the cyclist; while 14 of 25 (56%) were the fault of a motor vehicle driver. The most common manner of collision is when a driver strikes a cyclist from behind.

Full Report

The full report is available in pdf format:
Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009
Supporting data: 2009CyclistFatals.xls

Comments or questions may be left here, or contact me.

There were some somewhat out-of-context statements about my report on the npr.org health blog. They probably should have mentioned that the report covers only FATAL bike-MV collisions (a tiny fraction of all bike-MV collisions), and that the manner of collision in fatals varies significantly from non-fatals.

Read the rest of this entry »

Arizona bicyclist fatalities 2003-2006

How did I miss this one?

Should State DOTs Prefer Bicycle Lanes or Wide Curb Lanes? A.L. Dennison, 2008 [.pdf] This report was produced for ADOT in cooperation with US DOT/Federal Highway Authority.

Bicycle facility advocates have long debated the respective merits of bicycle lanes (BLs) and wide curb lanes (WCLs); this report investigates their claims… This study found no apparent relationship between fatal bicycle/motor vehicle collisions and type of bike facility… A significant handicap to any analysis of bicycle travel or safety is the paucity of reliable data.

Of great interest to me was the categorization of bicyclist fatalities over a four year (2003-2006) period, based on police reports. Somehow I missed this report entirely even as I echoed its complains about the “paucity of reliable data” for cyclist/traffic collisions while researching Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009.

According to my (from ADOT’s Arizona Crash Facts) records there were 15, 27, 35, 30 fatals in 2003, 2004, 2005, and 2006, respectively. This totals 107, but the report says that “We obtained 85 (97%) of 88 microfilmed fatal bicyclist/motorist crash reports submitted to AzDOT by police agencies in Arizona between 2003-2006″. The missing 3 (88-85) are explained in a footnote. But one wonders, where are the other 19? (=107 – 88). Does that mean that not all fatalities are submitted to ADOT? … so the answer i am told is that it covers the time period 17-Oct-2003 to 25-Sept-2006, which makes sense.

U.S. lagging in reducing traffic fatalities

AP Story U.S. lagging in reducing traffic fatalities. With all the feel-good news items about how fatality rates are supposedly so low, it’s good to get some perspective. The US is way behind in reigning in traffic deaths, and has fallen behind most other developed countries in both per-mile and is waaay behind in per-capita rates. Traffic deaths remain the leading cause of death for a huge swath of Americans.

And Arizona is even worse than US averages. For contrast, see what we’ve done with photo-enforcement in Arizona.

The large improvements in particular in US in the past few years are likely simply the result of poor economic conditions (no job means no job to drive to; and no money to spend driving around) — and not of some sort of systemic shift. Read the rest of this entry »

Obtaining Police Reports

As part of my project to monitor the most serious bicycle – vehicle collisions, I will be obtaining the Arizona Crash Report(ACR) for every bicyclist fatality in 2009. Read the rest of this entry »

Pre-preliminary 2009 Bicyclist Fatality Report

[update: this posting has been superseded -- please see:

Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009

which has detailed, finalized stats and discussion]

First, some perspective: In the state of Arizona, approximately 1,000 people are killed per year in traffic collisions of all types. The number of cyclist (usually called a “pedalcyclist” in the jargon) fatalities fluctuated between15 and 36 per year over the past twenty years, with an average of about 25/year.

[as a sidebar, Arizona total traffic fatalities which have been as high as 1,293 just a couple of years ago, were down to 937 for 2008.  The exact cause of this happy trend is a matter of great debate, e.g. the effect of economic recession, and photo-enforcement. Even after this dramatic reduction Arizona roads remain significantly more dangerous than US averages ]

I have become increasingly frustrated by what seems to me to be short-shrift paid to analysis of crashes resulting in a cyclist’s serious injury/fatality Read the rest of this entry »

It’s official; 2009 state-level NHTSA traffic fatality figures published

Get them here.

Here’s a typical national news story, from the LaTimes Traffic Deaths and Injuries Plummet in 2009: “Fatalities drop 9.7% from 2008 as the number of deaths dips to its lowest point since 1950, the Transportation Department says.” The official toll for 2009 is 33,808.

Closer to home, the total for 2009 in Arizona of 807 traffic fatalities represents a significant year-over-year drop that began in 2006, when there were 1,293 fatalities.

Per mile (VMT) figures won’t be available for awhile; it appears Arizona, which is consistently more dangerous than US averages will continue to close the gap.

Per capita figures show Arizona, again, consistently more dangerous than US averages, but continuing to improve.

Bicyclist Statistics

Bicyclists, statistically did not fare well in 2009. At 25 deaths, that is 6 higher than 2008, bucking the overall trend. Though the usual caution applies, the number of cyclist deaths is (thankfully) quite small, so a variation of just a few makes large percentage differences, and trends are harder to discern year-over-year.

Prior to the official release, i was aware of 16 fatalities; I am now aware of another 9 but they are  identified only by date time and (usually) location — but not name.  I was shocked to find out that Phoenix had 9 fatalities, of which I only knew about 4 previously. How can that be?

You can view a summary spreadsheet of each of the 25 fatalities here.

There is a detailed report available: Manner and Fault in Bicyclist Traffic Fatalities: Arizona 2009.

Arizona “Benefits”?

The Arizona Republic’s take included the odd conclusion that “Arizona benefits from being a younger state” thus the roads here are newer thus safer.

Arizona benefits from being a younger state. Because most development here is relatively recent, the roads are newer and designed to safer, more modern standards.

That means wider lanes and shoulders, better signs, smoother curves and banks, more guard rails and more innovations such as rumble strips, which are ruts in the sides of highways that alert drivers when they veer off the road.

“These are things people drive by every day which they may or may not notice. But they all contribute to make our roads safer,” said Laura Douglas, an Arizona Department of Transportation spokeswoman.

Rumble strips, for example, reduce the accident rate by a third, she said. ADOT also paints extra-thick road stripes, installs new guard rails that cushion crashes and uses larger, easier-to-see traffic signals, Douglas said.

Arizona traffic death toll drops to a 16-year low 9/11/2010, The Arizona Republic

This might be true in isolated examples, such as the rumble strips. Overall, though, this ignores the human-behavior dimension of driving. So, e.g. newer roads are much wider and straighter and the likely result is that drivers will drive faster. Maybe you’ll get relatively fewer wrecks but the ones that occur will be more violent as a result. If you look at the state-level NHTSA figures you will find the safest state is….. drumroll please… Massachusetts! A very old state. Arizona’s VMT rate is over twice as deadly as Massachusett’s. The disparity in per capita rate, since Arizonans drive more miles, is even worse.

Massachusetts happens to be the safest state in the US, but it’s not an outlier, the relationship holds up generally — states where most development pre-dated automobiles have far lower death rates, and vice versa.

“Better” roads also have a vicious circle effect of raising the number of miles driven, thus exposing one to more risk, albeit a decreasing risk per mile. In other words, dwelling on rate per VMT is misleading. Likewise, “better” vehicles, which are from an engineering perspective are much safer, have not yielded the expected improvement. Since as usual, human-behavior kicks in and drivers, knowing their vehicles are “safer”, (unconsciously or not) drive just a little more risk.

FARS

Cindie Holub’s death on March 1,  (Cindy’s death was written up on bicyclelaw.com, also see 2010 fatalities), from injuries sustained in a Feb 24 collision with a garbage truck caused me to look up the rule for categorization purposes. “To be included in this census of crashes, a crash had to involve a motor vehicle traveling on a trafficway customarily open to the public, and must result in the death of a person (occupant of a vehicle or a nonmotorist) within 30 days of the crash.” from DOT HS 811 137.

The US DOT runs a very elaborate, publicly available, query-able database for every traffic fatality in the US called FARS — Fatality Analysis and Reporting System. Read the rest of this entry »

New Crash Forms / ALISS database

As of Jan 1, 2009(?); Arizona has new forms. The old “Arizona Traffic Accident Report” will now be an “Arizona Crash Report” (as an aside, if you don’t know why that is significant, please see here). You can see what’s on the new form here, in a presentation by Rick Turner; includes the tantalizing bullet point “Customers Will Be Able to Query, Analyze and Retrieve Their Own Crash Data”. Read the rest of this entry »

Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles

This ponderously-name technical report from the NHTSA, Incidence of Pedestrian and Bicyclist Crashes by Hybrid Electric Passenger Vehicles [DOT HS 811 204 pdf here]

Has a bunch of interesting tidbits. It’s obviously leading or suggesting that quieter motorvehicles, particularly at low speeds where tire noise would be less significant, have a tendency to not be heard by cyclists or peds thus leading to more crashes. Sounds plausible. The difference may explain some human behavioral factors of operators of bicycles; such as why cyclists rarely make a complete stop, yet rarely get seriously injured in those situations. (Motorist, too, rarely stop but that’s another story)

What mainly caught my eye was a juicy dataset as describe in the METHODS section “State crash files from NHTSA’s State Data System (SDS)… The SDS includes all police-reported crashes, regardless of the injury or crash outcomes”. Though the SDS actually only contains records for 32 states, arizona not being one of them.

Who’s Responsible?

There is a claim floating around that some study has concluded that motorists are responsible for some 90% of car-bike collisions.

This would be a lot higher than is generally appreciated. I’ve grappled with this a little bit before in Understanding Collision Summaries, where I pointed out an inexplicably high proportion of  “other” violations assigned to bicyclists.

So far, I’ve found a page at projectfreeride.org with a table that is said to be source from Tomlinson, David. Conflicts Between Cyclists and Motorists in Toronto, Canada. Link to a .pdf on the Velomondial.net.

The same claim can be found in a newslettery article dated Aug 19, 2009 on a University of Toronto website entitled Smart Cycling. the information was supplied by a physcian, Dr. Chris Cavacuti, who is also involved with projectfreeride. And a correction with that article that was posted Aug 26:

In the interview, Dr. Cavacuiti is quoted as saying “The [Toronto Collision] study concluded that cyclists are the cause of less than 10 per cent of bike-car accidents”. Dr. Cavacuiti has asked us to make readers aware that the Toronto Collision study was actually designed to look at the cause of bicycle/motorist collisions but not culpability.

It is actually several studies conducted by the Charles Komanoff and member of the Right of Way organization in New York that concluded that concluded that cyclists were strictly culpable for less than 10 per cent of bike-car accidents.

Dr. Cavacuiti would like to apologize for any confusion this error may have caused.

On the projectfreeride page,  in a statement summarizing Tomlinson’s findings, the page at projectfreeride says “In fact, cyclists are the cause of less than 10% of bike-car accidents in this study”. Is that really what Tomlinson found? Or should the correction mentioned above be also applied to the projectfreeride page too?

This claim got picked up by the Freakonomics blog, garnering wide exposure.

Skepticism at the commuteorlando blog. Links the 90% claim back to Komanoff’s group Killed by Automobile paper. More links here on cycledog.

(more to come…)

See my own figures for manner-and-fault-in-bicyclist-traffic-fatalities-arizona-2009 which, according to the police reports/investigation, found motorists most-at-fault in about 50% of fatal traffic collisions between a MV and bicyclist in 2009.