4,402 CRASHES IN
IOWA, IA
SEPTEMBER 2015

During this period, 29 people were killed and 1,820 were injured in traffic crashes. Motorists comprised the largest group of casualties, with 24 killed and 1,714 injured. Vulnerable road users also suffered significant harm, with 4 pedestrians killed and 46 injured, and 1 cyclist killed and 55 injured.

Crash frequency peaked midweek, with Wednesday recording the highest number of incidents at 804. The afternoon commute was the most hazardous time of day, with the 3 p.m. hour seeing a peak of 391 crashes. While the majority of collisions occurred during daylight hours (3,096), a significant number also happened in darkness (806).

Of the 4,402 total crashes, 66.3% (2,917) resulted in no injuries, involving only property damage. The remaining 33.7% of crashes involved some level of injury, including 25 fatal crashes. These 25 incidents resulted in a total of 29 fatalities, highlighting that a single crash can lead to multiple deaths.

Severity is per crash event (most severe injury). 25 fatal crash events resulted in 29 persons killed.

The leading contributing factor cited in crashes was 'Followed too close,' attributed to 576 incidents or 13.1% of the total. Collisions involving an animal were the second most common factor, with 402 incidents. Other significant factors included failure to yield right-of-way from a stop sign (267 incidents) and drivers losing control of their vehicle (244 incidents).

The majority of crashes occurred in ideal driving conditions. Specifically, 71.3% of crashes (3,138) happened in clear weather, 80.5% (3,543) on dry road surfaces, and 70.3% (3,096) during daylight hours. Crashes in adverse conditions were less frequent, with 329 incidents occurring during rain and 410 on wet roads.

Among the 9,821 individuals involved in crashes, the 26-34 age group was the most represented, with 1,608 people. Analysis of the 7,862 vehicles involved shows that Chevrolet (1,521), Ford (1,243), and Dodge (600) were the most frequent makes recorded in collisions. These figures represent the makes of vehicles involved, not a reflection of vehicle safety or fault.

The most frequently cited major cause for crashes was 'Followed too close,' accounting for 576 incidents. The second leading cause was collisions with an animal, noted in 402 crashes. Other primary causes included failure to yield right-of-way from a stop sign (267 crashes), losing control of the vehicle (244 crashes), and failure to yield while making a left turn (243 crashes).

The most common first harmful event was a 'Collision with a vehicle in traffic,' which occurred in 2,754 crashes. Collisions with animals were the second most frequent event, recorded 399 times. Run-off-road incidents were also common, with crashes where the first harmful event was hitting a ditch (184) or an overturn/rollover (148) being significant contributors.

Crashes were more likely to occur on non-intersection road segments, which accounted for 2,048 incidents. Four-way intersections were the most common type of junction for crashes, with 1,113 incidents occurring at these locations. T-intersections were the next most frequent crash site, with 341 incidents.

Passenger cars were the most common vehicle type involved in crashes, accounting for 3,821 of the vehicles. Sport utility vehicles (1,588) and four-tire light trucks or pickups (1,176) were the next most frequent. Commercial vehicles like tractor-trailers were involved in 187 crashes, while motorcycles were involved in 139 incidents.

A majority of vehicles involved in crashes (4,461) were at locations with no traffic controls present. Where controls were present, traffic signals were the most common, associated with 1,740 vehicles in crashes. Stop signs were the next most frequent traffic control device, involved in crashes with 882 vehicles.

The front of the vehicle was the most common area of impact, recorded as the most damaged area for 2,150 vehicles. This aligns with the high number of rear-end collisions, as the rear was the second most common damage area, noted on 1,163 vehicles. Damage to the driver-side and passenger-side corners was also frequent, indicating a significant number of angle collisions.

Driver impairment was suspected or confirmed in 145 crashes, representing 3.3% of all incidents. Alcohol was the most cited impairment, involved in 131 of these crashes. Drugs were a factor in 10 crashes, and a combination of alcohol and drugs was noted in 4 crashes.

Crash distribution was concentrated in the state's most populous counties. Polk County had the highest number of incidents with 805 crashes, accounting for 18.3% of the statewide total. Scott County followed with 355 crashes, and Linn County had 289 crashes.

The highest crash volumes were recorded in Iowa's major cities. Des Moines led with 463 crashes, followed by Davenport with 256, Cedar Rapids with 176, and Sioux City with 171. These urban centers accounted for a significant portion of the total statewide crashes.

The vast majority of crashes, 4,146 incidents, occurred on paved roadways. However, a notable number of crashes, 238 in total or 5.4% of the subset, occurred on Iowa's unpaved road network. This highlights the distinct risk environment presented by gravel and dirt roads in the state.

In a minority of crashes, a roadway factor was noted as a contributor. The most common factor was the road surface condition, such as being wet or icy, cited in 111 crashes. Work zones were the second most frequent roadway-related factor, contributing to 92 crashes.

While most drivers were recorded as 'apparently normal,' several other conditions were noted. The most frequent was 'under the influence of alcohol' with 176 drivers. Other notable conditions included 'asleep/fatigued' (61 drivers) and 'emotional' (49 drivers), indicating that driver state plays a role in a subset of crashes.

Crash distribution across Iowa DOT's maintenance districts was uneven, reflecting population and traffic density. District 1, which includes the Des Moines metro area, recorded the highest number of crashes with 1,308. District 6, covering eastern Iowa including Cedar Rapids and Davenport, was a close second with 1,238 crashes.

The most common estimated property damage cost was in the '$1,500 - $7,500' range, which applied to 3,097 crashes. A smaller but significant number of incidents resulted in more severe financial loss, with 982 crashes causing damage between $7,500 and $25,000, and 109 crashes exceeding $25,000 in property damage.

The data shows a near-even split for the most common crash types. Non-collision, single-vehicle incidents (such as rollovers or running off the road) accounted for 1,269 crashes (28.8%). Rear-end collisions were almost identically frequent, with 1,268 incidents (28.8%). Broadside collisions were the next most common type, accounting for 732 crashes or 16.6% of the total.

The vast majority of vehicles involved in crashes were moving straight ahead prior to the collision, an action recorded for 4,435 vehicles. Turning left was the second most common pre-crash maneuver, noted for 773 vehicles, followed by slowing or stopping, which was recorded for 525 vehicles.

For crashes involving non-motorists, the most frequently recorded action was 'Entering or crossing roadway,' which was documented in 72 incidents. The second most common circumstance was a non-motorist moving along the roadway with traffic, which occurred 15 times.

Of the 9,821 total individuals involved in crashes, the overwhelming majority were drivers (9,318). Passengers accounted for 391 individuals. The data also includes 56 bicyclists and 50 pedestrians who were involved in collisions during this period.

Among all persons involved, 29 suffered fatal injuries (K) and 152 sustained serious injuries (A). An additional 619 persons had minor injuries (B) and 1,049 had possible injuries (C). In total, 1,849 individuals were either injured or killed in these traffic incidents.

Among vehicle occupants for whom safety equipment use was recorded, 1,126 were noted as using both a shoulder and lap belt. Conversely, 175 individuals were recorded as using no restraints at all. The use of child safety seats was documented in 24 cases, including forward-facing, rear-facing, and booster seats.

Two-vehicle collisions were the most common scenario, accounting for 2,817 separate incidents. Single-vehicle crashes were the second most frequent type, with 1,294 occurrences. Crashes involving three or more vehicles were less common, with 235 three-vehicle incidents and 42 four-vehicle incidents recorded.