Tag Archives: MMUCC

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: Continue reading MMUCC C9 Manner of Crash

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