MMUCC C9 Manner of Crash

Executive Summary: You may have never heard of the MMUCC (Model Minimum Uniform Crash Criteria; a set of federal guidelines), it trickles down into every state’s motor vehicle crash reporting system. It’s somewhat analogous to the relationship between the UVC and state’s vehicle codes. The problem, I should say one problem, is non-motorists tend to get overlooked. One obvious example is delved into here — the “Manner of Crash”, e.g. angle, rear-end, sideswipe, etc. is ONLY defined when it involves two motor vehicles, leaving that data-field undefined when a crash is between a MV and bicyclist. Since bicyclists are vehicle drivers, the MMUCC should reflect that. Read on for a proposed change that’s on the table, and how you can vote/comment officially:

UPDATE Sept 2016. There is a PROPOSED CHANGE similar to the change I submitted a year or two ago (they’ve added animal-drawn vehicles; I think it would be better described as …or other non-motorized vehicle). You can support or otherwise comment on the proposed changes here. The deadline for responses is 5:00 p.m. ET on Friday, October 7, 2016!!

Here’s the change, extracted from Page 10 of this document, with the additions highlighted in yellow:

Issue C9: Modify definition The following is a proposal from a public stakeholder to modify the definition of “C9. Manner of Crash/Collision Impact.”

The identification of the manner in which two motor vehicles or a motor vehicle and a bicycle/animaldrawn vehicle in transportinitially came together without regard to the direction of force. This data element refers only to crashes where the first harmful event involves a collision between two motor vehicles or a motor vehicle and a bicycle/animal-drawn vehicle in transport.

Dear Highway Safety Expert:

The Model Minimum Uniform Crash Criteria (MMUCC) is a voluntary guideline developed jointly by NHTSA and GHSA to help states determine what crash data to collect at the scene and include in their state databases. The guideline is currently undergoing a complete review, with the goal of releasing the 5th edition in 2017. The review has been led by an Expert Panel of approximately 30 participants, including representatives of law enforcement, state traffic records coordinators, state and local departments of transportation, researchers, EMS and federal officials.

The panel has made a number of initial decisions, including the creation of separate sections for fatal crashes, large motor vehicles and non-motorists. It has recommended that states be given more flexibility in the way in which they collect data and has also proposed a few new data elements, including ones for automated vehicles and ignition interlocks.

Following the first meeting, the Expert Panel formed small working groups to review particular data elements and their attributes and recommend changes. In addition, respondents to an online forum (conducted in May) and to a Federal Register notice proposed additional changes to MMUCC. We have created a second online forum to solicit your opinions about these proposals.
The forum is now open at https://fs8.formsite.com/ghsa/mmuccforum2/index.html
... Please note that all comments submitted to the forum will be posted without change at http://www.regulations.gov, including any personal information provided. The deadline for responses is 5:00 p.m. ET on Friday, October 7, 2016.
If you would like to review the full list of proposals and questions prior to completing the forum, you may download them here: http://ghsa.org/images/mmucc/Proposed_Changes_to_MMUCC_2.pdf link now dead :-( 
.

UPDATE Sept 2017

For reasons that are not clear to me, issue C9 (a.k.a. proposal 4.2) was rejected, and will not be made to the MMUCC 5th Edition. The voting was 43 to approve vs. 17 to reject (20 were no opinion). There’s a breakdown by “Public Stakeholders”, 27 approve / 9 reject. Whereas “Expert Panel” was 16 approve / 8 reject.
I have no idea what the process within DOT is; there are some more-official explanations in this f.b. thread (group membership required)

Below is a proposed change to the MMUCC to clarify data collection when the first harmful event in a motor vehicle crash involves a bicycle…

Here is a full version of Patricia Kovac’s submission. Below is my submission. Submissions through some unknown (i mean, unknown by me) process become proposals to be voted on.

PROPOSAL (my submission) — Discussion / Reason for change:

Bicycles are legally defined as vehicles, or bicyclists are legally defined as the driver of a vehicle, throughout the United States. Crashes between motor vehicles and bicycles should therefore be fully documented in the same way as a crash between two motor vehicles. Currently, the crash data element C9. Manner of Crash / Collision Impact is only defined when two motor vehicles collide.

There is some evidence that most law enforcement officers already, perhaps unconsciously, conform to the changes proposed below — in Arizona, which has very similar definitions as element C9, investigators assigned a value besides ‘Other’ to about 80% of motor vehicle – bicyclist crashes.

The changes proposed below are all additions, no deletions, and shown in ALL CAPS:

C9. Manner of Crash/Collision Impact

Definition:
The identification of the manner in which two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE in transport initially came together without regard to the direction of force. This data element refers only to crashes where the first harmful event involves a collision between two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE in transport. See Appendix F for a diagram of the manner of collision.

Attributes:

• Front to Rear
• Front to Front
• Angle
• Sideswipe, Same Direction
• Sideswipe, Opposite Direction
• Rear to Side
• Rear to Rear
• Other
• Unknown

Rationale:
Important for evaluation of occupant injuries and structural defects. This data element can be used in conjunction with Motor Vehicle Maneuver/Action (V18) to describe the crash.

Arizona Changes effective 2017 #arizona2017

Although the proposed change to the MMUCC was rejected, the Arizona Crash Report Forms Instruction Manual has been updated to reflect the general spirit of that change…

old, e.g. 9th Edition, Revised July 2010

17 – MANNER OF CRASH IMPACT- Identifies the manner in which two motor vehicles in transport initially came together.

new,  11th Edition, Revised Sept 2017

17 ‐ MANNER OF CRASH IMPACT‐ Identifies the manner in which two motor vehicles in transport initially came together without regard to direction of force. If a vehicle hits a pedestrian or pedalcyclist, indicate the manner of crash impact based on the vehicle action, for example, use left turn if the vehicle was turning left when it struck the pedestrian/pedalcyclist.

note that above I said the spirit of the change; the actual wording chosen leaves some loose, probably unintended, ends. For example if a bicyclist is struck by a straight-going, opposite-direction vehicle while making a bad left, the logical choice for manner would be LEFT TURN, but that’s not what the new definition says.

Arizona (my recommendations leading up to the Sept 2017 revisions)

Arizona seems to be generally consistent with the MMUCC. Unlike the MMUCC, and a better approach in my opinion, Arizona defines the notion of a traffic unit, which can be any vehicle (motorized or otherwise), bicyclist, or pedestrian — in other words, instead of having vehicle level data, in Arizona it is simply unit level data. In Arizona a unit action, e.g. going straight, turning left, turning right, etc, is completely consistent for bicyclists as well as motorist, so there’s no confusion and no data is lost. The equivalent element in MMUCC is V18. Motor Vehicle Maneuver/Action which needlessly restricts the data to a motor vehicle.

In Arizona, a person riding a bicycle has the same rights and responsibilities as the driver of a vehicle,   §28-812.  The relevant data field on the Arizona Crash Report is block 17 see Arizona Crash Form Manual, Rev. 8/2010 , [archived copy] page 37.

The way Arizona defines the manner of crash impact, though, by definition still has the same troubles as the MMUCC as noted above. Also note, Arizona defines two extra values: Single Vehicle (which makes sense to me, however it’s inconsistent with the definition) and Left Turn (which also makes sense to me.  A left turn is really just a special case of Angle).

Thus the proposed changes  in ALL CAPS:

17 – MANNER OF CRASH IMPACT- Identifies the manner in which two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE in transport initially came together, OR A SINGLE MOTOR VEHICLE CRASH NOT INVOLVING ANY OTHER TRAFFIC UNITS.

1. Single Vehicle – There is not a collision between two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE in transport.

2. Angle (front to side) (other than left turn) – Two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE approaching from an angle; usually resulting in a “T-bone” crash.

3. Left Turn – Two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE are traveling in opposite directions, prior to the crash, where at least one vehicle is making a left turn.

4. Rear End (front to rear) – A crash where the front of one motor vehicle OR BICYCLE impacts the rear of another motor vehicle OR BICYCLE AND AT LEAST ONE UNIT IS A MOTOR VEHICLE.

5. Head-On (front to front) (other than left turn) – A crash where the front ends of two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE impact together.

6. Sideswipe, Same Direction – Crashes where two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE are traveling the same direction and impact on the side….

7. Sideswipe, Opposite Direction – Crashes where two motor vehicles OR A MOTOR VEHICLE AND A BICYCLE are traveling the opposite direction and impact on the side…

8. Rear-to-Side – A crash where the back of one motor vehicle OR BICYCLE impacts the side of another motor vehicle OR BICYCLE. Vehicle #1 backing out of a parking space and striking vehicle #2 in the side

9. Rear-to-Rear – A crash where the backs of two motor vehicles impact together. This impact type could occur as in the first example below where the car loses control and spins 180 degrees impacting the rear of the truck. Another possible scenario would be two vehicles backing from roadside parking and impacting rear-to-rear.

97. Other… If “Other” is used it must  (emphasis in original) be listed on the line provided or described in the narrative.

99. Unknown – This would indicate that the Investigating Officer could not determine which Manner of Collision occurred.

Some more random thoughts

Animal-drawn wagons, e.g. horse and buggy, should probably be included somewhere; again, they are typically, as are animal riders, defined as vehicles or assigned driver’s rights and responsibilities.

I would think it would be appropriate to set a special value for pedestrian — i.e. when the first harmful event is pedestrian, there should be a specific/new value.

Arizona Data 2010-2021

Below is year-by-year results for Arizona Bike-MV crashes. At the time of this writing (March 2023), 2021 is the last full year available. Also note that things were odd in 2009 (the oldest dataset I have on-hand).

It would seem that OTHER is still running around 40 – 50%, which is probably high; I mean higher than it ought to be considering the explicit change to the Manual’s definition.