ADOT Traffic Collision Database

It turns out (who knew?) that ADOT sells their crash database for a nominal sum. I purchased the 2010 version, the latest full-year available (2011 is supposed to be ready in July).

The data is delivered on a DVD which contains three large text files; corresponding to Incident, Person, and Crash -level data. It is also accompanied with 5 photocopied pages of “Column Headings”, and about two-dozen pages of photocopied “Definitions”. [it is really strange that they would distribute this information on paper!?]. I was surprised to find out that very little of the data aligns with FARS/GES, which seems quite strange to me.

Anyway, I pieced together most of the info using those photocopies and assembled it for ready-reference in a spreadsheet adsm.xls , there is one worksheet for columns (fields) and another for defintions (ENUM). I don’t have all the definitions there, some i didn’t care about and were very lenghy, like vehicle color, state abbreviations, and so forth; nearly all of that is avaible at the referece material

Reference Material

…

• ADOT Crash Facts: handy for correlating and double-checking data
• NHTSA Traffic Records Team Home page, AZ Page
• AZ_Tablesfor2010_Crash_Reports.pdf: this almost matches the “definitions” photocopies, mentioned above.
• Arizona Crash Report 2010 : sample/blank ACR form
• Arizona Crash Form Manual, Rev. 8/2010 : detailed instructions on how the ACR is supposed to be filled out
• Background info on the ALISS database,  and related terms: AIDW (Adot Information Data Warehouse), and Safety Data Mart.

…

The Database

azbikelaw.org is making this data available publicly via a MySQL database accessible via the internet. Special thanks to Justin Pryzby for completing this work.

hostname:     asdmadmin.db.4318490.hostedresource.com
databasename: asdmadmin
username:     asdmuser
password:     Contact us
access via myPhpAdmin

The tables were loaded from raw text files using this script notes.txt, and subsequently re-processed with the script notes3.sql to create tables: incident2, person2, and unit2

There are some additional helper tables, such as LOVCity, LOVCounty and county which are handy for looking up things like city codes (e.g. Phoenix has a CityID of 241).

One Arizona legislator REALLY doesn’t like photo red cameras

Our legislative elves have been hard at work trying to de-rail photo-enforcement. Again (click here for last year’s festivities). The biggest single item is supposedly dead as of March 6, 2012 — this would have referred a ballot measure which would prevent cities and towns from using photo-enforcement.

Safety studies have consistently shown a net safety benefit for photo-red enforcement. Net means that there are fewer serious injuries and fatalities. A few studies have shown an increase in the number of collisions accompanying the safety gains. See, e.g. the IIHS study, Red Light Running Kills, linked at trafficsafetycoalition.com. Or more locally, also see Scottsdale-based redmeansstop.org.

Here is a list of items in the current session (spring 2012) of the Arizona Legislature, assembled by the Traffic Safety Coalition:

• SB1315 - mandate personal service or certified mail for photo enforcement tickets
• SB1316 - mandate that photo enforcement cameras cannot take pictures of red light running violations unless the light has been red for at least one second
• SB1317 - mandate a study of intersections with red light cameras
• SB1318 - force photo enforcement companies to obtain a PI License for each worker
• SCR 1029 - put photo enforcement ban to the voters for approval

As noted above Senate Concurrent Resolution 1029 is for the time-being anyway dead… The first thing I noticed that was odd is that they are all in the senate. Upon closer inspection all four of the the senate bills have only one sponsor, and all four are the same guy; a Frank Antenori (R-30, Tucson). He clearly doesn’t like photo-enforcement, and is apparently making it his life’s work to defeat it’s effectiveness; if not ban it outright.

Aside from safety issues, the cameras can, and do, provide evidence that has been used to solve crimes; including (that I know of) catching a hit-and-run driver who seriously injured a cyclist in Tucson, a hit-and-run-driver who killed a cyclist in Tempe, and a assault-robbery-murderer in Tempe.

Stats?

Arizona has a particular problem with red-light running; despite improvement over the years, Arizona continues to be over-represented. For example in 2009 Arizona had 37 red light running (RLR) fatalities while New York had only 29…. Arizona being three times as dangerous as New York on a per capita basis.

The words below, written over 10 years ago continue to ring true today, from a 07/13/00 article in USA Today, Ariz. has deadliest red-light runners in USA:

Arizona has the nation’s deadliest red-light runners, with three of the country’s worst cities for fatal intersection crashes, according to a study of federal transportation data obtained by USA TODAY….  Arizona had by far the worst death rate among states, with 6.5 fatalities for every 100,000 people… Arizona also had three of the four most dangerous cities. for red-light fatalities. Phoenix topped all urban areas, followed by Memphis, Mesa and Tucson

In addition, cities with speed limits of 45 mph and higher on surface streets faced more serious red-light -running accidents… The Phoenix police officer says said that with an average of 330 days of sunshine a year, it’s typically usually perfect driving weather. That doesn’t mean motorists drive perfectly, however. Just the opposite. “If we got more rain or inclement weather, maybe it would slow people down some, particularly at the intersections,” Halstead said says. “As it is, they zip around the city at a pretty good clip.” And, according to the institute’s study, Phoenix drivers run red lights at an unrivaled pace. The city has by far the nation’s deadliest rate of fatal red- light running crashes, nearly five times the national average. Arizona and other fast-growing Western states have been particularly stung by red light crashes “because their wide open roads are suddenly seeing schools, businesses, and busy intersections crop up,” says said Phoenix traffic engineer Paul Wellstone. “The West has a reputation for being a drivers’ paradise; a place you can lay on the accelerator and not worry about the traffic and dangers. That’s changing now. Cities are struggling with getting their citizens to slow down.”

 The FHWA has a page on red light running.

Is Phoenix Safe?

Phoenix was reputed to be America’s 7th safest city, according to this survey which looked at three factors relating to insurance. Clearly the stuff of newspaper-filler stories. Intrigued, I see that the survey involves ranking cities in three categories 1) Crime, 2) Natural disasters, and 3) Traffic safety; though it wasn’t clear how they were weighted. For example, traffic fatalities claim far more lives than murder, and the number of deaths in the U.S. due to natural disaster is miniscule.
That being as it may, their source for traffic safety rankings is the “Allstate America’s Best Drivers Report” (tm!), which Allstate claims “Reveals Safest Driving Cities”.

What it actually measures is the statistical likihood of having an auto insurance claim. Which Allstate claims, and I think sounds reasonable, as a proxy for the number of MV collisions. The next leap, which is demonstrably false, is that fewer collisions translates into “safety”. One glaring data point is enough to disprove this: cities of similar size are frequently and for good reasons ranked against one another; it just so happens that Phoenix and Philadelphia have virtually the same population, and are currently the 5th and 6th largest city in the U.S. Actual fatality data reveal that Phoenix is significantly more dangerous than Philadelphia, yet Allstate’s proxy data says just the opposite:

Source: NHTSA Traffic Safety Facts 2009 (latest year available), Table 124 811402.pdf, and Allstate (follow link above; current year result they refer to as 2011, is similar to 2005-2010 ). Notes: overall U.S. fatals/population/ratePer100K = 33,808/307,007,000/11.01

So, Allstate’s data merely shows that Phoenicians suffer from fewer fender-benders than Philadelphians; but say nothing about safety.

Why is Phoenix so dangerous? The main reason is probably because it’s “Dangerous by design”, with a higher priority on moving more cars, at higher speeds; and a lower priority on getting everyone to their destinations without being killed. More driving could explain some but not all of the gap; this, in itself, a symptom of poor land-use choices.

I threw Seattle into the table simply because of this recent op-ed that aggravated me: why-seattle-is-safer-than-phoenix. Phoenix and Seattle are quite dissimilar in population, but here again the Allstate data claims Seattle is far safer than Phoenix when it is just the opposite that’s true.

By the way

I always have trouble finding this page at www-nrd.nhtsa.dot.gov (which can be found by searching for FARS, then clicking on “publications”) where it lists publications like Traffic Safety Facts; e.g. 2009 Traffic Safety Facts Data Summary Booklet ; and 2009 Traffic Safety Facts FARS/GES Annual Report, they list back to about earlier 1990′s.

2010 FARS and PBcat

Commencing with the recently-released 2010 data FARS (The USDOT’s Fatality Analysis and Reporting System) will have far more specialized detail on Pedestrian and Bicyclists crashes.

618 cyclists (person type 6 bicyclist, and 7 other pedalcyclist) were killed in 2010 in traffic collisions — and as noted at the link above, only collisions with motor vehicles in-transport are tracked by FARS. So for example, a bicyclist who lost control and died as a result of crashing into a tree would not be tracked here, nor would a bicyclist who strikes a parked motor vehicle.

The added information becomes a new “table” (in the parlance of databases), if you download the raw data files, it will be all found in the file PBtype.dbf

The information follows more-or-less exactly the PBcat, probably no coincidence. PBcat is the Pedestrian and Bicyclist Crash Analysis Tool, and contains among other things the bicyclists direction, and a detailed crash type (or for the complete reference, see PBcat’s manual, appendix C)

So, say you were interested in bicyclists running stop signs; you would do a query and then a univariate split and take a look at Types 142, 144, and 147; all subtypes of “Bicyclist Failed to yield — Sign-Controlled Intersection”. There were 17+41+1 = 59 such fatalities recorded.

Since this is the first and only year where these national stats are available, they are of limited usefulness — that will change over time as the dataset grows and wil become a very useful comprehensive source of understanding bicyclist (and pedestrian) traffic fatalities.

PBcat in the wild

It’s not clear to me why, but the state of North Carolina had PBcatted all their ped and bike crashes statewide for many years; leading to a very rich database of statistical information. E.g. 12,000 bike crashes covering the period 1997-2008!

In Arizona, ADOT as part of the BSAP has PBcatted 746 bike crashes in the “concentration” areas but it only covers the state-highway system. See e.g. Table 1 in working paper 3 for the full breakout of crash types.

Is Bicycling Dangerous?

Short answer: yes, as with all modes of transportation, it entails some danger.

Longer answer: yes, similar to the risk of motoring — perhaps twice as risky. but how to measure? (per mile, per trip?). Bike-MV collisions are currently running 2% of all in AZ. Bicycling represents perhaps 1%, i.e. twice the risk.

For the moment, this is going to be a catch-all for links and related info on the topic. Links:

• http://www.bicyclinginfo.org/facts/crash-facts.cfm
• http://www.kenkifer.com/bikepages/health/risks.htm
• Mighk Wilson’s essay freedom from fear .
• Another essay in the same vein by a UK sociologist Dave Horton: Fear of Cycling.
• My posts about the books How Risky is it Really? and Free Range Kids.

Read the rest of this entry »

Final 2010 U.S. Motor Vehicle Traffic Fatalities released

Final 2010 figures

…released 12/8/2011;  fastlane.dot.gov, at 32,885 the number is slightly higher than the early estimates which come out in the spring.

The 2010 dataset is not yet available in FARS, which is a little strange given that last year’s data was released in September (i.e. 2009 dataset available September 2010). update: the 2010 FARS data came up sometime in early December.

Final Arizona 2010 figures were released in August.

Bicyclist Fatalities

As bikinginla.wordpress.com  points out, 618 cyclist deaths in 2010 makes it the lowest overall figure in some 35 years. The Arizona figure, 19, puts it close to our 10-year average; coming off of a bad 2009 (25).

Ped Problems?

USA Today article: ”The USA is getting riskier for people on foot, and experts aren’t sure why.” Mike Sanders noted the ped issue, see comment here on the final Arizona 2010 figures.   Speed matters and need to redefine mobility – “Everyone should be familiar with the chart that shows that a pedestrian hit by a car traveling at 20 miles per hour (mph) percent survivability rate. That same collision with a car going twice as fast, 40 mph, will lower the survivability likelihood to 15 percent” (Laplante and McCann, Complete Streets: We Can Get There from Here, ITE journal, May 2008).

An rather than viewing it as a zero-sum game where motorists must lose mobility in order to make streets safer for peds; Beyond Safety in Numbers suggests that the safer streets for peds are quite likely safer streets for motorists as well.

Early Estimate of Motor Vehicle Traffic Fatalities in 2010

The early estimates come out in the spring (late march i think), here was the buzz at that time…

The media is abuzz with projections released a couple of days ago by NHTSA that 2010 traffic fatalities are at there lowest number since the Truman administration, and the closely-watch per VMT figure is the lowest ever recorded. Early Estimate of Motor Vehicle Traffic Fatalities in 2010:

A statistical projection of traffic fatalities in 2010 shows that an estimated 32,788 people died in motor vehicle traffic crashes. This represents a decline of about 3 percent as compared to the 33,808 fatalities that occurred in 2009…  The fatality rate for 2010 are projected to decline to the lowest on record, to 1.09 fatalities per 100 million VMT, down from 1.13 fatalities per 100 million VMT in 2009

Here are the Early Estimates for 2009, and 2008. Read the rest of this entry »

Arizona has the highest cycling fatality rate?

[updated October 2010: Final data for 2009 has AZ as 4th highest bicycling fatality rate (per capita, i.e. per population). See e.g. this media story referring to the BSAP]

Tied to April being bike month in Arizona is of course a crop of media stories.

Imagine how surprised I was to read that “Arizona has the highest cycling fatality rate, based on population in the United States”. Read the rest of this entry »

ADOT’s Bicycle Safety Action Plan Study

ADOT’s Bicycle Safety Action Plan Study (BSAP) is a multi-phase plan to assess and improve bicycle traffic safety, with emphasis on Arizona state highways. In urban areas that often means the interchanges.

During the five-year study period “There were a total of 9,867 bicycle crashes statewide in Arizona…  crashes that occurred on state highways were extracted from the statewide data set. There were 1,089 bicycle-motor vehicle crashes reported on state highways between January 1, 2004 and December 31, 2008″ (see Working Paper 1, Section 4.2).

Thus this data set accounts for a small minority of bike-MV crashes, around 11%. But Working Paper 1,  table 15 offers a useful comparison between the studied data and all statewide data. For example, we see the same suspiciously-high percentage (24 to 25%) of “other” fault ascribed to bicyclists as with other studies. As I’ve written before, the “other” fault is generally the result of a poor/improper crash investigations that tends to wrongly faults cyclists who are doing nothing illegal (see Understanding Collision Summaries) — this is statistical proof of poor-quality investigations are a statewide problem for bicyclists. This is a shortcoming of the crash reports, and not the BSAP;  in Working Paper 1, figure 20, something they call “primary contributing factor” by crash group is assigned overwhelmingly to motorists (67%), and only 24% to bicyclists.

Press coverage

There was a lengthy, front page A1,  Arizona Republic article by Sean Holstege on Sept 17, 2011 which perhaps was intended to be about the plan but did wander, understandably, to general topics. For example they make great hay out of the per capital fatality stats, without any discussion of how to interpret them — e.g. how weather probably affects them, with Arizona being more of a year-round cycling state; or a higher per capita usage, e.g. Arizona has significantly higher (than US) percentage of commuters (according to census figures, see Working Paper 1, Table 1 — Arizona is 0.9% versus 0.5% nationwide).

The story, as many “bicycle safety” stories do, lacks context of traffic in general. So, for example, there was a chart of the number of bike-MV collisions (about 2,000/year total). There is no mention of the fact that that represents only a tiny fraction of all MV collisions ( which ran well over 100,000/year over the study period). And though it mentions the number of fatalites, say 25 in 2008 — it never mentioned the total number of traffic fatalities (it runs around, and lately something under, 1,000 per year).

So here are some hard numbers, over the five year period 2004 – 2008 there were 681,466 MV crashes, of which 9,730 were bike-MV — a little less than 1.5% (taken from the historical overview in the 2009 Bicyclist Fatality study, which were gleaned from AZ Crash Facts — note that the numbers a slightly different in the BSAP, but I don’t know why). The number of fatalities is 4,943 total, 132 bicyclist; or 2.67% — so bicyclist fatalities were somewhat over-represented but not dramatically so.

Note that the ADOT plan by design is aimed at the small percentage of bike-MV crashes that occur on the state highway system. “The majority of bicycle crashes in Arizona (approximately 90 percent) occur on local, city, and county roadways outside of ADOT jurisdiction”

Also, by the way, the article inaccurately stated that the BSAP recommends a mandatory taillight law. That was in an earlier draft but was since removed — I don’t believe there is adequate evidence to support the additional burden on cyclists. The article does correctly mention that the BSAP recommends state-level sidewalk law clarifications, which seem like a worthy endeavor, given the huge proportion of sidewalk-related collisions, along with the current legal murky morass that currently exists when cyclists who cycle on the sidewalk subsequently collide with vehicles in crosswalks and driveways.

—

See more about Media Bias in bicycling safety stories.

ADOT 2010 Crash Facts

ADOT’s 2010 Motor Vehicle Crash Facts has just been released.

Highlights are the total number of fatalities continued to fall; there were a total of 762 persons killed in 2010, a 5% decrease from the year before.

There were 19 bicyclists killed on Arizona’s road in collisions with motor vehicles in 2010, which compares favorably with the 25 killed in 2009. That means there are two (possibly three) missing from this tally for 2010.

The MOST COMMON DRIVER VIOLATION is (remains) Speed too fast for condition

There were 106,177 crashes in total, of which 1,914 were bike-MV crashes.

Dangerous by Design

While we’re on the subject, t4america.org released the latest version of their recurring report Dangerous By Design 2011; where metro-Phoenix has a recurring, starring role as a particularly dangerous place for pedestrians — the 8th worst rate in the US. The only places significantly higher are basically several (!) metro areas in Florida.

Bad for pedestrians tends to translate into bad for motorists and bicyclists, as well — in other words, we’re all in this together.  Arizona’s motorist fatality ”VMT rate  is over twice as deadly as Massachusett’s. The disparity in per capita rate, since Arizonans drive more miles, is even worse…. more”

But you are not likely to hear anything about how or if or why Arizona isn’t closing the gap; or even that a gap exists! — rather that deaths overall have merely fallen. Here is a typical new-release-style story: azfamily.com story

Back to the DbyD report, they have this concept called PDI, the Pedestrian Danger Index; Phoenix-metro at 132 is many times worse than, for example, Boston-metro at 21.6.

And just to throw out a factoid, for the year 2009 (the most recent year for which detailed stats are available) there were more bicyclists killed within the City of Phoenix (9) than were killed in the entire state of Massachusetts(6).

The population of Phoenix is 1.5M versus State of Massachusetts having 6.5M…. The C.O.P., accused rightly as being an enormous-sprawling place covers 516 square miles, the state of Massachusetts 7,840 square miles of land area.

John Allen’s blog reflecting upon the fact that in the DbyD report, the Boston-metro area came in dead last (SAFEST!) of all large metro areas in US — “Strange, isn’t it — the Boston area has repeatedly been derogated as supposedly having the nation’s craziest drivers”.

Arizona’s Rural Highway Traffic Safety Problem

A couple of days after the data was released, and somewhat to my chagrin, the arizonarepublic/news/articles/2011/09/02/20110902arizona-deadly-rural-roads.html did a fairly long and detailed piece on what ADOT is doing to identify and address rural highway problems… though, interestingly, the latest Crash Facts shows a steeper decline in rural as opposed to urban fatalities.

So far, no one that I know of, has said or suggested that Arizona’s high rate of rural fatalities is what accounts for Arizona’s overall high traffic fatality rate. Perhaps that is so?

As mentioned in the article, rural fatal crashes tend to be single-vehicle — though that is a little misleading because a bike-MV, or ped-MV crash is defined as a single-vehicle.

Here are the number of fatal crashes split by urban/rural for 2009 and 2010:

Peds fatal crashes, total/urban/rural: 156 / 102 / 54 ( 2009: 121 / 77 / 44)

cyclists killed, total/urban/rural:         19 / 17/ 2 ( 2009: 25 / 17 / 8 )

(all inclusive) Number of fatal crashes, total / urban / rural: 698 / 354 / 344 (2009: 709 / 299/ 410)

…

Here is some discussion of the 2010 National results: early-estimate-of-motor-vehicle-traffic-fatalities%C2%A0in%C2%A02010/

IIHS Driver Fatality Rate Stats

The IIHS does this every so often, e.g. see here for their report from a couple of years ago.

So, the latest is Dying in a Crash, Vol 46, No. 5, June 2011. It covers 2005-08 model year passenger vehicles during calendar years 2006-09. It also specifically only covers driver fatality rates.

The big news is that SUVs, which long have had higher death rates than passenger cars — due to the much higher rollover deaths — have become safer, due presumably to the prevalance of ESC (electronic stability control) in newer model SUVs.

There is no accounting for attempt to account for danger imposed on others.

What the WSJ Thinks

The WSJ has been running the same editorial and op-eds for as long as there’s been a CAFE (Corporate Average Fuel Econonmy, probably 30 years old now) Read the rest of this entry »