Tag: ASDM

A Tale of Five Phoenix Bike-MV collisions.

Fault was assigned to the bicyclist in four of the five reports. In two of those, the bicyclist was doing something obviously illegal/wrong (riding the wrong way in the roadway, and running into a stopped vehicle). However, the other two do not support that finding — in one a motorist violated a bicyclist’s ROW by turning into it, and in the other a bicyclist was struck by a motorist who was attempting to turn right-on-red.

Perhaps the reason Phoenix has a persistently high bicyclist MaF (Most at Fault) rate is the officers are often not investigating bike-MV crashes correctly?

Continue reading “A Tale of Five Phoenix Bike-MV collisions.”

Driver slams into day spa; 1 dead, 4 go hospital

[Updated; as expected/suspected this death and injuries DO NOT appear in official crash records from ADOT, nor will they appear in the FARS when that is released. See this comment for how I checked asdm]

9/27/2013. A story like this, besides being a tragedy, tends to make headlines (even going national,  usatoday.com story) but, Seriously, how often does stuff like this happen? Apparently regularly; like the shopper killed inside a Tucson convenience store in July…. or… 11-year old boy dead in a Phoenix parking lot in May… or … 2 Dead in Phoenix after pickup slams into bus stop  in March… or… 1 Dead at a Peoria Walgreens sitting on the bench in front of store in 2010… This is just what i noticed reading the paper; These were all in the recent past, just in Arizona. This is not a complete list! ha. Continue reading “Driver slams into day spa; 1 dead, 4 go hospital”

GIS, mapping, crash reports vs. ASDM

Some notes on mapping using the latitude/longitude; and the ASDM (Adot Safety Data Mart) dataset.

Here is a detailed breakdown of a crash chosen more-or-less at random (I wanted to choose crashes that were *not* at intersections) that occurred 2012-10-12 at a driveway just east of 51st Ave on Indian School Rd. (if the link doesn’t work use 33.494971/-112.167771, the lat/long specified in ASDM). It is ADOT incident number 2672854, Phoenix file number 12001836231 (though it was listed as 201836231 in ASDM). Continue reading “GIS, mapping, crash reports vs. ASDM”

Collision Manner

[Warning/correction not yet made: in the table below where it says MV-only, that’s not quite correct, it’s really incidents where no pedalscylists are involved. The MV-only calculations should also exclude pedestrians; this can be accomplished by saying u.eUnitType LIKE ‘PED%’  In the query below i corrected it but didn’t correct the table; the percentages don’t really change since there are relatively few ped crashes ]

Here is a breakdown of Collision Manner, and rates, for MV collisions (i.e. one or more MV, and not involving a ped or bicyclists) compared to bike-MV collisions.

The megatrends are that rear end collisions are, by far, the predominant manner of collision for MVonly crashes; wheres for bike-MV crashes this manner is quite infrequent — almost twelve times more frequent. For bike-MV crashes, the predominant manner is angle, i.e. so called “turning and crossing” movements (although left turn is broken out as a separate manner).

The 38% rate of REAR END crashes for MVs actually understates the rate — if you back out the number of SINGLE VEHICLE crashes; you see that nearly half of all multi-car collisions are REAR END(!). 38,499/(101,055 – 18,647) = 47%. Inattention? Does this mean that motorists actually are more attentive to same-direction traffic when it’s a bicyclist, compared to another motorist? hmmm.

+------------------------------+-------+--------+------+--------+-------------+
| eCollisionManner             | MVonly| MVrate |bikeMV|bikerate|MV:bike ratio|
+------------------------------+-------+--------+------+--------+-------------+
| REAR_TO_REAR                 |   287 | 0.0028 | NULL |   NULL |        NULL |
| UNKNOWN_99                   |   859 | 0.0085 |   40 | 0.0189 |  0.44973545 |
| REAR_TO_SIDE                 |   895 | 0.0089 |   11 | 0.0052 |  1.71153846 |
| SIDESWIPE_OPPOSITE_DIRECTION |  1244 | 0.0123 |   46 | 0.0217 |  0.56682028 |
| HEAD_ON                      |  1438 | 0.0142 |   45 | 0.0212 |  0.66981132 |
| OTHER_97                     |  3160 | 0.0313 |  404 | 0.1905 |  0.16430446 |
| SIDESWIPE_SAME_DIRECTION     | 10727 | 0.1062 |  124 | 0.0585 |  1.81538462 |
| LEFT_TURN                    | 11888 | 0.1176 |  189 | 0.0891 |  1.31986532 |
| ANGLE_FRONT_TO_SIDE          | 13411 | 0.1327 | 1194 | 0.5629 |  0.23574347 |
| SINGLE_VEHICLE               | 18647 | 0.1845 | NULL |   NULL |        NULL |
| REAR_END                     | 38499 | 0.3810 |   68 | 0.0321 | 11.86915888 |
+------------------------------+-------+--------+------+--------+-------------+
total num of MVonly crashes = 101,055.  total num of bike-MV crashes = 2,121
source: 2012 ASDM

Continue reading “Collision Manner”

Data Collection of Bicyclist Helmet Use in Crashes

I have some questions/concerns/misgivings about helmet usage as it relates to bicyclist safety and crash reports. It seems to me that it is not well-reported… (update; sometime in the late 2010s this was updated; skip below to the 11th edition…

Arizona Crash Report (10th Edition)

Curiously, given the hoopla intense interest surrounding bicyclist helmet usage, there is NO place on the ACR to report whether or not a bicyclist was using a helmet. There is a block for each traffic unit(4dd) and passenger(5c), SafetyDevice  lists things like helmet/airbag/seatbelt and so forth. However, this block is always supposed to be coded 0/Not Applicable, and is explicitly never to be 1/None Used, or 5/Helmet Used for pedalcyclists. See p.23, 26 of 2010 Arizona’s Crash Report Forms Instruction Manual. (this was block 4ff)

Clearly this is often coded not according to the manual, see below for some live data e.g. from 2010. We might guess that the 10% or so that say Helmet Used probably does mean those bicyclists had helmets, and likewise probably the 35% that said None Used probably means not helmet. But the other 55% is (from the data) anybody’s’ guess.

There is likewise no place on the ACR to code for nighttime crashes whether or not a bicyclist was using required lighting equipment (a front headlight or a rear taillight/reflector).

Arizona Crash Report (11th, 12th & 13th Edition)

the helmet business was changed and made explicit. Some of these changes were in the 11th edition (I have only a draft), below is what is in the 13th Edition, Revised August 2023: here are the salient bits, with my emphasis added:

5ff ‐ Safety Devices - The restraint equipment in use by the occupant, or the helmet use by a motorcyclist, at the time of the crash.
0. Not Applicable - Use for driverless/parked vehicles or pedestrians. Do not use this code for motorcycle operators or pedalcyclists.
1. None Used - Any occupant of the motor vehicle (driver, passenger) did not use a device or in the case of a motorcycle or pedalcyclist, did not use a helmet.
5. Helmet Used - This attribute applies to helmets used by drivers and passengers of all motorized cycles (motorcycles, mopeds, minibikes, motor scooters, and all-terrain vehicles) This should also be used for non-motorists such as pedalcyclists or a pedestrian on a skateboard

 

So that’s that. This field shows up in the database in the person table as SafetyDevice. Although there are still hundreds of “NOT APPLICABLE” for pedalcyclists despite being explicitly wrong, per the manual. At a few hundred, there are also more UNKNOWNS thank I would like to see. There are also a couple dozen apparent oddballs like seat belts, even one airbag(!). See comment below for sample data dump from 2010 and 2024.

SELECT SafetyDevice, eSafetyDevice, count(*) FROM 2021_person
WHERE ePersonType LIKE 'PEDAL%' GROUP BY 1, 2 ORDER BY SafetyDevice;

I didn’t check into the other issue regarding lighting, there’s some other fields, but only in the fatal suppleement regarding non-occupant safety devices: things like reflective clothing, lights; in any event that doesn’t get captured into the (state) database, though it presumably gets passed along into FARS.

FARS

For 1994 through 2009; all persons including bicyclists and other pedalcyclists used the P10 Restraint/Helmet Use field. The column was called REST_USE in the person table.

From 2010 and later, this info was moved to a whole new dataset, the SafetyEq table. the column name is MSAFEQMT; and it’s slightly annoying because it’s indexed by ST_CASE (i.e. the case number), and person number. There can be any number of records for any given person.

The field is called NM13 Non-Motorist Safety Equipment “This element indicates the safety equipment that was used by the non-motorist
involved in the crash”, in the FAR Manual. In the FAR Validation Manual, there’s an elaborate confusing explanation of differentiating between Not Reported and Unknown. Allowable values are:

  1. None
  2. Helmet
  3. Reflective Clothing (jacket, backpack, etc.)
  4. Protective Pads Used (elbows, knees, shins, etc.)
  5. Lighting
  6. (not used)
  7. Other Safety Equipment
  8. Not Reported
  9. Unknown if Used

 

For reference, you can see mmucc.us‘s field P23 Non-Motorist Safety Equipment from (MMUCC is a nhtsa-funded group that sets standards for data collection on traffic crash reports). This is consistent with FARS definition; except that mmucc says only two may be selected for any person, and FARS allows any number to be selected (theoretically, the vast majority have either one or two selected).

 

It’s like a war zone out there…

Walk in the crosswalk; get hit with flying debris from a red-light-runner? Seriously, how often does this happen? (note to self — check ASDM for 2013, whenever that becomes available, and see if the peds show up in the collision — my guess is no but i really don’t know what the story is)

azcentral.com: …At about 9a.m. Sunday (3/10/2013), Kaylynn Ruth Kayanie, 25, was driving west on Broadway “at a high rate of speed” when she ran a red light and struck another vehicle that was traveling south on Priest Drive… The driver of the southbound vehicle, a 45-year-old woman, was ejected and taken to the hospital with life-threatening injuries…  Two pedestrians who were in the crosswalk heading south on Priest at the time of the collision were hit by flying debris and taken to the hospital, where they were treated for cuts and bruises and released the same day, she said. Impairment does appear to be a factor in that case and investigators are awaiting drug-test results

The same story notes that the suspected impaired driver Veronica Muckerman made a bad left, killing a motorcyclist Elsa Tovar last week; was apparently driving without a license, due to being revoked in 2011 for another dui.

ADOT Traffic Collision Database

ACIS — Arizona Crash Information System; was ASDM?

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). This data is either similar to (or synonymous with) something referred to as the Arizona (or ADOT?) Safety Data Mart — thus the acronym asdm sprinkled throughout. Continue reading “ADOT Traffic Collision Database”

Arizona Agency NCIC Numbers

This info will be only of interest for those working with the ADOT Data Safety Mart database.

There are a couple of places on the ACR form for NCIC numbers. That stands for National Crime Information Center; and the actual number in question apparently is called an Originating Agency Identifier (ORI) and it’s keeper is the FBI. Below I will refer to this number only as the “NCIC number”.

I found it surprisingly difficult to find a list. The only place I found it was in a 12 year old(!) AZ Crash Manual (“Manual of Instructions for use with State of Arizona Traffic Accident Report Forms” published by ADOT dated December 2000), so the info regarding Agency name should be suspect.

It is plain to see that some of it is easily verifyable  and correlates to any of the “big” cities/jurisdictions: Phoenix PD is 0723, DPS is 0799, Tucson PD is 1003, etc. Beyond a couple of dozen, though, things get pretty sketchy.

Of more interest is the meaning of the distinction between data fields ExtendedNcic, and OfficerNcic — the field on the ACR is marked simply NCIC No. (Block 1e), which i imagine maps to ExtendedNcic; however I can’t find a block on the ACR that might correspond to OfficerNcic. They are usually, but by no means always, the same. There’s another thing called Officer ID No., Block 1f, but that maps to OfficerID in table incident.

This info is also in my famous catch-all spreadsheet adsm.xls; and will undoubtedly either turn into enumerations, or probably its own table.

 

Arizona NCIC Numbers
National Crime Information Center number is a code that uniquely identifies each law enforcement agency. Numbers are assigned by the Federal Bureau of Investigation. (See pages 66 through 68 [of the year 2000 version of AZ Crash Manual] for a complete list of Arizona NCIC Numbers.)
ExtendedNcic, OfficerNcic’s value/count data from ADOT safety data mart year 2010. Agency name list from pages 66 -68 of the year 2000 version of AZ Crash Manual
ExtendedNcic OfficerNcic From 2000 AZ Crash Manual
value count value count agency name value
100 474 100 40 Apache County S.O. 100
101 28 101 28 Eagar 101
103 18 103 18 St. Johns 103
105 12 105 10 Springerville 105
Whitemountain Apache Res. (Apache) 162
189 73 Navajo Reservation (Apache) 189
200 693 200 224 Cochise County S.O. 200
201 89 201 55 Benson 201
203 4 203 1 Bisbee 203
205 41 205 37 Douglas 205
207 7 207 8 Huachuca City 207
209 756 209 763 Sierra Vista 209
211 1 Tombstone 211
213 39 213 32 Willcox 213
300 1539 300 223 Coconino County S.O. 300
301 1909 301 1762 Flagstaff 301
302 1 Hualapai Reservation (Coconino) 302
303 6 Fredonia 303
307 97 307 43 Williams 307
308 21 308 21 Page 308
310 195 310 197 Sedona 310
Hopi Reservation (Coconino) 365
389 34 Navajo Reservation (Coconino) 389
Northern Arizona University 397
400 484 400 134 Gila County S.O. 400
401 172 401 178 Globe 401
403 2 403 1 Hayden 403
405 13 405 13 Miami 405
406 142 406 139 Payson 406
407 1 489 4 Winkelman 407
Whitemountain Apache Res. (Gila) 465
San Carlos Reservation (Gila) 489
500 124 500 38 Graham County S.O. 500
501 3 Pima 501
503 105 503 95 Safford 503
505 45 505 49 Thatcher 505
San Carlos Reservation (Graham) 562
600 60 600 13 Greenlee County S.O. 600
601 6 601 3 Clifton 601
603 4 Duncan 603
700 5242 700 3036 Maricopa County S.O. 700
701 1044 701 890 Avondale 701
703 405 703 256 Buckeye 703
704 56 Cave Creek 704
705 3516 705 3007 Chandler 705
707 321 707 311 El Mirage 707
709 20 Gila Bend 709
711 2378 711 2250 Gilbert 711
713 4822 713 4492 Glendale 713
715 939 715 635 Goodyear 715
Ft. McDowell Reservation 716
717 6130 717 4744 Mesa 717
719 193 719 131 Paradise Valley 719
721 2237 721 1855 Peoria 721
723 29065 723 21442 Phoenix 723
725 3529 725 3329 Scottsdale 725
727 1027 727 904 Surprise 727
729 6659 729 4084 Tempe 729
731 366 731 237 Tolleson 731
733 93 733 89 Wickenburg 733
735 13 Youngtown 735
739 300 Guadalupe 739
744 3
753 41
755 116
756 97 Fountain Hills 756
760 15 Carefree 760
Gila Bend Reservation 762
Tohono O’Odham Res. (Maricopa) 763
Gila River reservation (Maricopa) 764
789 1 Salt River Reservation 789
Arizona State University 797
799 25587 Dept. of Public Safety 799
800 1140 800 326 Mohave County S.O. 800
801 537 801 478 Kingman 801
804 629 804 632 Hualapai Reservation (Mohave) 802
805 683 805 684 Lake Havasu City 804
806 18 806 18 Bullhead City 805
Colorado City 806
Kaibab-Paiute Reservation 860
862 3 Ft.Mohave Reservation 862
900 647 900 141 Navajo County S.O. 900
901 60 901 41 Holbrook 901
902 19 Hopi Reservation (Navajo) 902
903 164 903 167 Show Low 903
905 64 905 81 Snowflake 905
907 19 Taylor 907
909 134 909 117 Winslow 909
913 118 913 124 Pinetop/Lakeside 913
962 72 Navajo Reservation (Navajo) 962
989 2 Whitemountain Apache Res. (Navajo) 989
1000 4424 1000 3324 Pima County S.O. 1000
1001 70 1001 69 South Tucson 1001
1003 9718 1003 9058 Tucson 1003
1004 192 1004 157 Sahuarita / Green Valley (both same code??) 1004
1007 454 1007 462 Oro Valley 1007
1009 916 1009 679 Marana 1009
San Xavier Reservation 1062
1089 220 Tohono O’Odham Res. (Pima) 1089
1097 117 University of Arizona 1097
1100 1779 1100 703 Pinal County S.O. 1100
1101 853 1101 796 Casa Grande 1101
1103 172 1103 179 Coolidge 1103
1105 149 1105 97 Eloy 1105
1107 81 1107 111 Florence 1107
1109 5 1109 4 Kearney 1109
1111 4 1111 4 Mammoth 1111
1112 2 1112 1 Superior 1112
1113 417 1113 377 Apache Junction 1113
1117 215 1117 211
1164 7 Tohono O’Odham Res. (Pinal) 1164
Maricopa Reservation 1165
1189 345 Gila River Reservation (Pinal) 1189
Central Arizona College 1197
1200 294 1200 75 Santa Cruz County S.O. 1200
1201 342 1201 313 Nogales 1201
Patagonia 1203
1300 1378 1300 283 Yavapai County S.O. 1300
1301 1 1301 1 Clarkdale 1301
1303 244 1303 237 Cottonwood 1303
1305 6 1305 5 Jerome 1305
1307 760 1307 749 Prescott 1307
1311 539 1311 536 Prescott Valley 1311
1312 87 1312 87 Chino Valley 1312
1313 92 1313 72 Camp Verde 1313
1314 1
1358 11
Hualapai Reservation (Yavapai) 1363
1400 716 1400 484 Yuma County S.O. 1400
1403 26 1403 31 Somerton 1403
1405 1891 1405 1849 Yuma 1405
1407 7 Wellton 1407
1408 137 1408 139 San Luis 1408
1410 5
1497 1 Arizona Western College 1497
1500 330 1500 32 La Paz County S.O. 1500
1501 33 1501 31 Parker 1501
1503 35 1503 18 Quartzite 1503
Colorado River Reservation 1506
Sums → 106301 106301
Below are listed Federal Parks and Monuments, and US Military – it is not clear how, or even if, these codes (from 2000) map to the Adot data, which is all numeric; and perhaps doesn’t even cover “federal” investigations?
Canyon De Chelly National Monument I007
Casa Grande Ruins National Monument I012
Chiricauha National Monument I013
Glen Canyon National Monument I003
Montezuma Castle National Monument I014
Navajo National Monument I009
Organ Pipe Cactus National Monument I015
Petrified Forest National Park I004
Saguaro National Monument I005
Sunset Crater National Monument I010
Tonto National Monument I016
Tumacacori National Monument I017
Tuzigoot National Monument I018
Walnut Canyon National Monument I019
Wupatki National Monument I011
Davis Monthan AFB F001
Ft. Huachuca Army Base USA0
Luke AFB F003
Yuma Proving Grounds Army Base SA02 SA02

Most at Fault vs. NCIC

Most at Fault is defined in the Arizona Crash Form Manual

Traffic Unit #1 is the vehicle, pedestrian, pedalcycle that caused the collision or was most at fault.

Police determine or decide who is most at fault, by assigning #1 to that person/operator when filling out the Arizona Crash Report; note that there is no defined way to indicate that investigators find it impossible to determine fault; there must be a unit #1.

(The stats quoted can be found in this comment below)
It can be illuminating to study who, the bicyclist or the motorist, was most at fault (MaF) in a Bike-MV collision. All things being equal, we would expect a 50:50 split, because in the vast majority of collisions there is one bicycle operator, and one MV operator.

The MaF data is available in the yearly collision database from ADOT, a.k.a. the ASDM; the vehicle/person/bicyclist listed as Unit #1 is always the MaF, in the determination of the investigating officer.

Reassuringly, overall the MaF rates are indeed fairly close to 50:50 — for example, the seven year period 2009-2015 the split was 51:49, indicating bicyclists were every so slightly more likely to be found at fault that the driver they collided with. Deviations from this nominal rate might indicate something is amiss; perhaps bicyclists in one community are more likely to break the law, or perhaps police are misinterpreting laws in someone’s favor…

The NCICs associated with the city of Phoenix has a particularly high bicyclist MaF rate: e.g. 68% in 2010 — compare this to, e.g. Scottsdale where it was only 48%. I find it pretty unlikely that bicyclists in Phoenix behave significantly different than Scottsdale; though without looking at a lot of ACRs it’s not possible to tell. On the other hand, 2010 seems to have been anomalously high that year, 2011 and 2012 were 61 and 60%, respectively; so perhaps just a data glitch. On the other hand Tempe, at 68% in 2012, and seems persistantly somewhat high. Yuma, a small city, had a persistently very high bicyclist MaF rate, as high as 80%!, this may be changing after the local ordiance restricted & clarified sidewalk use rules in 2015.

Here are some queries; note that similar results are used using either OfficerNcic as ExtendedNcic. The first is very fancy, computing the percentages and everything!

SELECT sum(atfault)/count(1), Name, sum(atfault), count(1) FROM LOVNcic, (SELECT ExtendedNcic, u.eUnitType='PEDALCYCLIST' atfault FROM 2012_incident i, 2012_unit u WHERE i.IncidentID=u.IncidentID AND EXISTS (SELECT 1 FROM 2012_unit u2 WHERE u2.IncidentID=i.IncidentID AND u2.eUnitType='PEDALCYCLIST') AND UnitNumber=1) x WHERE ID=ExtendedNcic GROUP BY ExtendedNcic HAVING count(1)>20 ORDER BY 1;

Here is how to select the total number of bike crashes by ncic, and then the number of those where bicyclist is MaF

SELECT ExtendedNcic,count(1) FROM 2012_incident i WHERE EXISTS (SELECT 1 FROM 2012_unit u WHERE u.IncidentID=i.IncidentID AND u.eUnitType IN ('PEDALCYCLIST')) GROUP BY 1 ORDER BY 1 ASC;
SELECT ExtendedNcic,count(1) FROM 2012_incident i WHERE EXISTS (SELECT 1 FROM 2012_unit u WHERE u.IncidentID=i.IncidentID AND u.eUnitType IN ('PEDALCYCLIST') AND u.UnitNumber=1 ) GROUP BY 1 ORDER BY 1 ASC;

…