4,336 CRASHES IN
IOWA, IA
JUNE 2015

Motorists comprised the largest group of individuals killed or injured, with 20 fatalities and 1,464 injuries. Vulnerable road users also suffered significant harm; 3 pedestrians were killed and 31 were injured. Additionally, 1 cyclist was killed and 50 were injured during this period.

Crash frequency in Iowa during this period peaked on Mondays, which saw 777 incidents. The single busiest hour for crashes was the afternoon commute period from 4:00 PM to 4:59 PM, with 371 events. A significant majority of crashes, 2,983 or approximately 69%, occurred during daylight hours.

The majority of crashes, 3,051 out of 4,336 (70.4%), resulted in no injuries and involved only property damage. The remaining 29.6% of crashes involved some level of injury, including 114 serious injury crashes and 440 minor injury crashes. There were 23 distinct fatal crashes, which resulted in a total of 25 fatalities, as a single crash can involve 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 identified in crashes was an animal in the roadway, cited in 758 incidents (17.5%). Following this, driver behaviors such as following too closely (409 crashes, 9.4%), losing control of the vehicle (262 crashes, 6.0%), and failure to yield the right-of-way from a stop sign (245 crashes, 5.7%) were the next most frequent causes.

The vast majority of crashes occurred in ideal driving conditions. Approximately 69% of incidents (2,983 crashes) happened in daylight, 70.5% (3,058 crashes) on dry road surfaces, and 52.5% (2,276 crashes) in clear weather. Adverse conditions were less frequent, with 443 crashes occurring during rain and 577 on wet roads.

Among the 9,030 people involved in crashes, the most represented age groups were 26-34 year olds (1,359 people), 16-20 year olds (1,285 people), and 45-54 year olds (1,213 people). Of the 7,347 vehicles involved, the most frequent makes were Chevrolet (1,430 vehicles), Ford (1,238 vehicles), and Toyota (516 vehicles).

The leading major cause attributed to crashes was an animal, responsible for 758 incidents (17.5%). Other significant causes included drivers following too closely (409 crashes), losing control (262 crashes), and failing to yield the right-of-way from a stop sign (245 crashes). Driver distraction was noted in several forms, including other interior distraction (90 crashes) and inattentiveness (61 crashes).

The most common first harmful event was a collision with another vehicle in traffic, which occurred in 2,376 crashes, representing 54.8% of the total. The second most frequent event was a collision with an animal, documented in 745 cases (17.2%). Single-vehicle run-off-road events were also common, with the first harmful event being a collision with a ditch (201 crashes) or an overturn/rollover (158 crashes).

Crashes occurred more frequently on non-intersection segments of roadway than at junctions. There were 1,938 crashes recorded at non-junction locations. Among intersections, the most common type was a four-way intersection, which accounted for 1,004 crashes, followed by T-intersections with 252 crashes.

Passenger cars were the most common vehicle type involved in crashes, accounting for 3,603 of the 7,347 vehicles. Sport utility vehicles (1,471 vehicles) and four-tire light trucks or pickups (1,082 vehicles) were the next most frequent. Commercial vehicles and motorcycles represented smaller portions, with 187 tractor-trailers and 168 motorcycles involved in incidents.

A large number of incidents, 4,130, occurred at locations where no traffic controls were present. For crashes at controlled locations, traffic signals were the most common device, present at 1,551 incidents. Stop signs were the second most common form of traffic control, noted in 705 crashes.

The front of the vehicle was the most frequent area of most severe damage, recorded for 1,855 vehicles. This was followed by the rear of the vehicle, which sustained the most damage in 979 cases, suggesting a high prevalence of rear-end collisions. Damage to the driver-side and passenger-side areas was also significant, with 410 and 316 vehicles sustaining primary damage to their middle sections, respectively, indicative of angle or broadside impacts.

Driver impairment was noted in 156 crashes, representing approximately 3.6% of all incidents. Of these, alcohol was the sole factor in 138 cases. Drugs were a factor in 15 crashes, and a combination of alcohol and drugs was recorded in 3 instances.

Crash distribution was heavily concentrated in Iowa's most populous counties. Polk County, home to Des Moines, recorded the highest volume with 796 crashes. It was followed by Scott County (329 crashes), Linn County (269 crashes), Black Hawk County (165 crashes), and Pottawattamie County (163 crashes). Together, these five counties accounted for nearly 40% of all crashes statewide.

The highest crash volumes were reported in Iowa's largest cities. Des Moines led with 444 crashes, followed by Davenport with 250, Cedar Rapids with 162, and Sioux City with 142. Dubuque rounded out the top five with 118 reported crashes during this period.

The vast majority of crashes, 4,113, occurred on paved roadways. However, Iowa's extensive secondary road network was also a factor, with 195 crashes, or about 4.5% of the total with known surface type, taking place on unpaved gravel or dirt roads.

In a minority of crashes where a roadway factor was cited as a contributor, adverse surface conditions such as wet or icy pavement were the most common, noted in 113 incidents. Work zones were a factor in 61 crashes. Other less frequent factors included debris in the roadway (16 crashes) and traffic backups (16 crashes).

Among drivers where a condition other than 'apparently normal' was recorded, being under the influence of alcohol was the most frequent, noted in 157 cases. Driver fatigue or falling asleep was the next most common condition, cited for 74 drivers. Other documented conditions included being emotional (34 drivers) and suffering from a medical event (32 drivers).

Crash distribution across the state's six DOT districts shows a concentration in the regions with major population centers. District 1, which includes the Des Moines metro area, had the highest number of crashes with 1,241. District 6, covering eastern Iowa including Cedar Rapids and Davenport, was second with 1,143 crashes. Together, these two districts accounted for 55% of all crashes in the state.

The most common estimated property damage cost per crash was in the range of $1,500 to $7,500, which applied to 3,165 incidents, or 73% of all crashes. High-cost crashes were less frequent, with 84 incidents (1.9%) resulting in estimated damages of $25,000 or more.

Single-vehicle, non-collision events such as running off the road or rollovers were the most frequent crash type, accounting for 1,204 incidents (27.8%). The most common multi-vehicle crash type was a rear-end collision, which occurred 1,034 times (23.8%). Broadside, or front-to-side, collisions were the third most common manner, with 658 incidents (15.2%).

The most common pre-crash action for vehicles involved was moving essentially straight, which was the case for 3,919 vehicles. The next most frequent actions were turning left (693 vehicles) and slowing or stopping in traffic (439 vehicles).

For non-motorists involved in crashes, the most frequently recorded action was entering or crossing the roadway, which was documented in 50 incidents. Other actions included moving along the roadway with traffic (11 incidents) and being on a sidewalk (6 incidents).

Of the 9,030 individuals involved in crashes, the vast majority, 8,589 people (95.1%), were drivers. Passengers accounted for 352 individuals (3.9%). Vulnerable road users represented a small fraction of the total persons involved, with 51 bicyclists and 34 pedestrians recorded.

Among all persons involved in crashes, a total of 1,573 individuals sustained some level of injury or were fatally wounded. This included 25 fatalities, 128 serious injuries, 555 minor injuries, and 865 possible injuries. These figures represent the human toll across all crash severities.

Among the subset of occupants for whom safety equipment use was recorded, 994 were reported as using a shoulder and lap belt. In 133 cases, it was noted that no safety equipment was used. For motorcycle and bicycle riders, 32 were recorded as wearing a DOT-compliant helmet.

Two-vehicle collisions were the most common scenario, accounting for 2,443 crashes. Single-vehicle crashes were the second most frequent type, with 1,625 incidents, representing 37.5% of the total. Crashes involving three or more vehicles were less common, with 265 such events recorded.