5,857 CRASHES IN
IOWA, IA
NOVEMBER 2015

Of the total persons killed or seriously injured (KSI), motorists comprised the largest group with 21 fatalities and 1,643 injuries. Vulnerable road users also suffered significant harm; two pedestrians were killed and 44 were injured. Additionally, while there were no cyclist fatalities, 23 cyclists were injured in crashes during this period.

Crash analysis reveals distinct temporal patterns, with Fridays being the most frequent day for incidents, recording 1,129 crashes. The daily peak occurred during the evening commute, with 708 crashes happening in the 5 p.m. hour. Overall, crashes were more prevalent during daylight hours, with the period from 6 a.m. to 6 p.m. accounting for a majority of the incidents.

Of the 5,857 crashes, 76.1% (4,457) resulted in no injuries, being classified as property damage only. The remaining incidents involved some level of injury, including 879 possible injuries, 403 minor injuries, and 99 serious injuries. There were 19 distinct fatal crashes, which resulted in a total of 23 fatalities, as a single crash can involve more than one death.

Severity is per crash event (most severe injury). 19 fatal crash events resulted in 23 persons killed.

The leading contributing factor cited in crashes was an animal, involved in 1,524 incidents (26%). Following this, common driver-related factors included 'Followed too close' with 521 crashes (8.9%), 'Driving too fast for conditions' with 397 crashes (6.8%), and 'Ran off road - left' with 332 crashes (5.7%). These top factors represent specific actions or circumstances identified by investigating officers.

A significant portion of crashes occurred in adverse conditions, though clear weather was most common, present for 2,468 crashes. Daylight conditions were reported in 2,491 crashes (42.5%). However, 1,066 crashes occurred on lighted roadways after dark and 755 on unlighted dark roads. While dry pavement was the most frequent surface condition (2,738 crashes), a combined 1,819 crashes occurred on wet, snow, ice, or slush-covered roads.

Among the 11,298 people involved in crashes, the 26-34 age group was the most represented, with 1,925 individuals. Analysis of the 9,428 vehicles involved shows that Chevrolet (1,912 vehicles), Ford (1,570 vehicles), and Dodge (714 vehicles) were the most frequent makes recorded in crash reports. Toyota (641 vehicles) and Honda (437 vehicles) were also commonly involved.

According to the Iowa DOT's major cause coding, collisions with an animal were the leading factor, attributed to 1,524 crashes. The next most common causes were driver behaviors, including 'Followed too close' (521 crashes), 'Driving too fast for conditions' (397 crashes), and 'Lost Control' (309 crashes). Failure to yield when making a left turn was also a significant factor, cited in 240 incidents.

The most common first harmful event was a 'Collision with: Vehicle in traffic,' which occurred in 2,831 crashes. The second-leading event was a 'Collision with: Animal,' accounting for 1,504 incidents. Single-vehicle events were also prominent, including 'Overturn/rollover' (208 crashes) and collisions with fixed objects like a 'Ditch' (206 crashes) or a 'Utility pole/light support' (108 crashes).

Crashes were most frequently located away from intersections, with 2,559 incidents occurring at 'Non-junction' locations. Four-way intersections were the most common type of junction for crashes, accounting for 1,174 incidents. T-intersections were the site of another 322 crashes, indicating that intersections collectively represent a significant point of conflict.

Passenger cars were the most common vehicle type involved in crashes, accounting for 4,538 vehicles. Sport utility vehicles (1,991 vehicles) and four-tire light trucks or pickups (1,540 vehicles) were the next most frequent. Commercial vehicles were also represented, with 255 tractor/semi-trailers involved in incidents, while 37 motorcycles were recorded in crashes.

The majority of crashes occurred where no traffic controls were present, with this category accounting for 5,152 incidents. Where controls were in place, traffic signals were the most common, associated with 1,888 crashes. Stop signs were the next most frequent traffic control device, present at the scene of 818 crashes.

The front of the vehicle was the most common area of impact, recorded as the most-damaged area for 2,316 vehicles. The rear of the vehicle was the second most frequent point of damage, with 1,133 instances, suggesting a high prevalence of rear-end collisions. Damage to the driver-side (456 middle, 409 front) and passenger-side (370 middle, 341 front) indicate a significant number of angle or sideswipe collisions.

A total of 149 crashes were flagged for driver impairment, representing 2.5% of all crashes. Of these, alcohol was the sole factor in 138 cases, drugs were the factor in 8 cases, and a combination of alcohol and drugs was noted in 3 cases. These figures should be considered a minimum, as impairment is often difficult to determine at the scene.

Crash distribution was heavily concentrated in Iowa's most populous counties. Polk County recorded the highest number of incidents with 922 crashes, followed by Scott County with 387 and Linn County with 317. Together, these three counties accounted for 1,626 crashes, representing 27.8% of the statewide total for the month.

Among municipalities, Des Moines experienced the highest volume of crashes with 494 incidents. Davenport followed with 298 crashes, and Sioux City recorded 218 crashes. These figures highlight that a substantial portion of traffic incidents occur within the state's primary urban areas, as many rural crashes happen outside of any city's jurisdiction.

The vast majority of crashes, 5,621, occurred on paved roadways. However, 210 crashes were recorded on unpaved surfaces such as gravel or dirt. These unpaved road crashes represent 3.6% of incidents where the surface type was specified, reflecting the risk present on Iowa's extensive secondary road network.

In a minority of crashes, a roadway factor was identified as a contributor. The most cited factor was 'Surface condition (e.g.wet, icy),' noted in 786 crashes. Work zones were a contributing factor in 54 crashes, while debris in the roadway was cited in 11 incidents.

While most drivers were recorded as 'Apparently normal,' several other conditions were noted by officers. 'Under the influence of alcohol' was the most common condition, recorded for 176 drivers. Other notable conditions included 'Asleep/fatigued' for 58 drivers and 'Emotional' for 37 drivers, suggesting that driver state plays a role in a subset of crashes.

Crashes were most prevalent in the Iowa DOT's District 1, which includes the Des Moines metro area, with 1,607 incidents. District 6, covering eastern Iowa including Cedar Rapids and Davenport, recorded the second-highest number with 1,474 crashes. These two districts combined accounted for over half (52.6%) of all crashes in the state.

The most common estimated property damage cost per crash fell within the '$1,500 - $7,500' range, which applied to 4,389 incidents. A smaller but significant number of crashes resulted in higher costs, with 1,222 incidents causing damage between $7,500 and $25,000. Crashes with severe damage estimated at over $25,000 accounted for 110 events.

The most frequent type of crash was a 'Non-collision (single vehicle)' event, such as running off the road or an overturn, accounting for 2,558 incidents (43.7%). Among multi-vehicle crashes, rear-end collisions were the most common, with 1,252 incidents (21.4%). Broadside collisions were also frequent, occurring in 771 crashes (13.2%).

The most common pre-crash action for vehicles involved was 'Movement essentially straight,' recorded for 5,369 vehicles. Other frequent actions preceding a collision included 'Turning left' (802 vehicles) and 'Slowing/stopping (deceleration)' (488 vehicles). These actions highlight common driving maneuvers that result in conflicts.

For the 46 pedestrians involved in crashes where an action was recorded, the most common behavior was 'Entering or crossing roadway,' which was noted in 44 instances. This indicates that pedestrians are most vulnerable while actively navigating traffic lanes. Another 8 incidents involved pedestrians going to or from school.

Of the 11,298 individuals involved in crashes, the vast majority were drivers, accounting for 10,829 persons. Passengers made up the next largest group with 396 individuals. Vulnerable road users were also involved, including 46 pedestrians and 23 bicyclists.

Among all persons involved in crashes, 23 suffered fatal injuries and 117 sustained serious injuries. An additional 526 people had minor injuries and 1,071 had possible injuries. The data shows that while a minority of individuals are injured in any given crash, the potential for severe outcomes is present.

Based on available data, 1,222 individuals were recorded as using a shoulder and lap belt. In contrast, 109 people were documented as using no safety equipment at the time of the crash. Additionally, 16 children were secured in a forward-facing child safety seat.

Two-vehicle crashes were the most common scenario, accounting for 2,957 incidents. Single-vehicle crashes were also very frequent, with 2,615 incidents recorded. Crashes involving three or more vehicles were less common, with 249 three-vehicle crashes and 30 four-vehicle crashes reported.