4,327 CRASHES IN
IOWA, IA
MAY 2015

Motorists comprised the vast majority of those killed or injured, with 24 fatalities and 1,614 injuries. Among vulnerable road users, one pedestrian was killed and 27 were injured. While no bicyclists were killed during this period, 41 sustained injuries.

Crash frequency peaked on Fridays, which saw a total of 845 incidents. The single busiest hour of the day was the 3 p.m. hour, with 397 crashes, indicating a strong correlation with the afternoon commute. Overall, 3,097 crashes, representing 71.6% of the total, occurred during daylight hours.

Of the 4,327 total crashes, 2,977 (68.8%) resulted in no injuries, involving only property damage. The remaining incidents involved injuries of varying degrees, including 114 serious injury crashes and 434 minor injury crashes. There were 23 distinct fatal crashes, which resulted in a total of 25 fatalities, as some incidents involved more than one death.

Severity is per crash event (most severe injury). 23 fatal crash events resulted in 25 persons killed.

The most common contributing factor cited in crashes was an animal in the roadway, accounting for 582 incidents (13.5%). This was followed by drivers following too closely, which contributed to 503 crashes (11.6%). Failure to yield the right-of-way from a stop sign was the third-leading factor, cited in 278 crashes.

The majority of crashes occurred in favorable conditions, with 3,097 (71.6%) happening in daylight and 2,875 (66.4%) on dry road surfaces. Clear weather was reported for 1,907 crashes, with an additional 1,274 in cloudy conditions. Crashes in adverse conditions were less frequent, with 605 incidents occurring during rain and 846 on wet roads.

Among the 9,400 people involved in crashes, the 26-34 age group was the most represented, with 1,480 individuals. Analysis of the 7,572 vehicles involved shows that Chevrolet (1,519 vehicles), Ford (1,160 vehicles), and Dodge (579 vehicles) were the most frequent makes recorded in crash reports.

The leading major cause attributed to crashes was an animal in the roadway, cited in 582 incidents. Following too closely was the second most common cause with 503 crashes. Failure to yield the right-of-way from a stop sign was the third leading factor, contributing to 278 crashes.

The most common initial event in a crash was a collision with another vehicle in traffic, which occurred in 2,614 incidents. The second most frequent first harmful event was a collision with an animal, recorded in 573 crashes. Single-vehicle events were also common, with 169 crashes involving a ditch and 113 involving an overturn or rollover.

Crashes were most likely to occur on non-intersection road segments, which accounted for 1,888 incidents. Four-way intersections were the most common junction type for crashes, with 1,116 incidents occurring at these locations. T-intersections were the site of 327 crashes.

Passenger cars were the most common vehicle type involved in crashes, accounting for 3,785 of the vehicles. Sport utility vehicles (1,504) and four-tire light trucks or pickups (1,108) were the next most frequent. The data also includes 168 tractor-semitrailers and 135 motorcycles involved in collisions.

A majority of vehicles involved in crashes, 4,274, were at locations with no traffic controls present. For crashes at controlled locations, traffic signals were the most common device, associated with 1,730 vehicles. Stop signs were the next most frequent control type, present for 798 vehicles in crashes.

Frontal impacts were the most common point of damage, recorded on 1,998 vehicles involved in crashes. Rear impacts, which are typically associated with rear-end collisions, were the second most frequent damage area with 1,038 instances. Damage to the driver's side was noted for 394 vehicles and to the passenger's side for 365 vehicles.

A total of 154 crashes were recorded as involving an impaired driver, representing 3.6% of all crashes. Of these, alcohol was suspected in 144 cases, drugs in 6 cases, and a combination of alcohol and drugs in 4 cases. These figures represent a minimum, as impairment is often under-reported.

Polk County, home to Des Moines, recorded the highest number of crashes with 857 incidents. Scott County followed with 322 crashes, and Linn County had 298. Together, the top five counties (Polk, Scott, Linn, Woodbury, and Johnson) accounted for 1,865 crashes, representing 43.1% of the statewide total.

At the municipal level, Des Moines reported the highest crash volume with 488 incidents. Other cities with significant crash counts include Davenport with 262 crashes, Cedar Rapids with 192, and Sioux City with 173. These figures highlight crash concentration in the state's primary urban centers.

The vast majority of crashes, 4,099 incidents, occurred on paved roadways. A total of 209 crashes, or approximately 4.9% of those with a recorded surface type, took place on unpaved surfaces such as gravel or dirt roads. This reflects the prevalence of Iowa's secondary road network in crash data.

In cases where a roadway factor was identified as a contributor, surface conditions such as wet or icy pavement were the most common, cited in 132 crashes. Work zones were noted as a factor in 53 incidents. Additionally, slippery, loose, or worn surfaces contributed to 27 crashes.

Among drivers where a condition other than 'apparently normal' was noted, being under the influence of alcohol was the most frequent, recorded for 173 drivers. The second most common condition was being asleep or fatigued, which was cited for 51 drivers. Emotional state and pre-existing medical conditions were also noted in 37 and 34 cases, respectively.

Iowa DOT District 1, which includes the Des Moines metro area, had the highest number of crashes with 1,272. District 6, covering eastern Iowa including Cedar Rapids and Davenport, followed closely with 1,210 crashes. These two districts combined accounted for over 57% of all crashes in the state.

The most common estimated cost of property damage was in the $1,500 to $7,500 range, which applied to 3,145 crashes. A smaller number of severe incidents, 70 crashes, resulted in estimated damages exceeding $25,000. Only 178 crashes were estimated to have damages under $1,500.

Rear-end collisions were the most frequent crash type, accounting for 1,116 incidents or 25.8% of the total. Non-collision events, such as single-vehicle run-offs or rollovers, were nearly as common, with 1,043 incidents (24.1%). Broadside collisions were the third most common manner of collision, occurring in 729 crashes.

The most common pre-crash action for vehicles was moving essentially straight, which was the case for 4,110 vehicles involved in collisions. Turning left was the next most frequent action, recorded for 749 vehicles. An additional 454 vehicles were in the process of slowing or stopping just before impact.

Among incidents involving pedestrians and bicyclists, the most frequently recorded action was 'Entering or crossing roadway,' which was noted in 49 cases. Other actions, such as moving along a sidewalk or in the roadway, were cited in much smaller numbers, with 6 and 9 instances respectively.

Of the 9,400 individuals involved in crashes, the vast majority were drivers, accounting for 8,896 people (94.6%). Passengers made up the next largest group with 427 individuals. The data also includes 42 bicyclists and 28 pedestrians who were involved in these incidents.

Among all persons involved in crashes, 25 sustained fatal injuries and 151 suffered serious injuries. Minor injuries were recorded for 564 people, while an additional 974 people had possible injuries. These figures illustrate the human impact across the full spectrum of crash severities.

Among the individuals for whom safety equipment usage was documented, 1,086 were recorded as using a shoulder and lap belt. Conversely, 146 individuals were noted as not using any safety equipment at the time of the crash. For motorcyclists, 29 were reported to be wearing a DOT-compliant helmet.

Two-vehicle collisions were the most common scenario, accounting for 2,692 crashes (62.2%). Single-vehicle crashes were the next most frequent type, with 1,382 incidents, representing 31.9% of the total. Crashes involving three or more vehicles were less common, with 214 three-vehicle incidents recorded.