4,059 CRASHES IN
IOWA, IA
AUGUST 2015

Motorists comprised the vast majority of those killed or seriously injured, with 45 fatalities and 1,694 injuries. However, vulnerable road users also suffered significant harm. Crashes resulted in 3 pedestrian fatalities and 21 pedestrian injuries. Additionally, there were 2 cyclist fatalities and 45 cyclist injuries during this period.

Crash frequencies peaked during the weekday evening commute. The single busiest day for crashes was Monday, with 667 incidents, while the peak hour was the 4 PM hour with 367 crashes. Overall, a significant majority of collisions, 2,928 or approximately 72%, occurred during daylight hours.

Of the 4,059 crashes, 2,671 (65.8%) resulted in no injuries, involving only property damage. The remaining incidents involved injuries of varying severity: 732 crashes with possible injuries, 485 with minor injuries, and 130 with serious injuries. There were 41 distinct fatal crashes, which resulted in a total of 51 fatalities, as a single crash can involve more than one death.

Severity is per crash event (most severe injury). 41 fatal crash events resulted in 51 persons killed.

The most frequently cited contributing factor to crashes was 'Followed too close,' attributed to 521 incidents (12.8% of the total). Other leading factors included collisions with an animal (299 crashes, 7.4%), drivers losing control of their vehicle (259 crashes, 6.4%), and failure to yield the right-of-way from a stop sign (244 crashes, 6.0%).

The majority of crashes occurred in ideal driving conditions. Data shows that 2,752 crashes (67.8%) happened in clear weather, 3,301 (81.3%) on dry road surfaces, and 2,928 (72.1%) during daylight hours. Crashes in adverse conditions were less frequent, with 303 incidents occurring during rain and 383 on wet roads.

Among persons involved in crashes, the 26-34 age group was the most represented, with 1,409 individuals, followed by the 16-20 age group (1,352) and the 35-44 age group (1,220). Analysis of the 7,239 vehicles involved shows that Chevrolet was the most common make with 1,447 vehicles, followed by Ford with 1,181 vehicles and Dodge with 516 vehicles.

The leading major cause identified in crashes was 'Followed too close,' which was cited in 521 incidents. Collisions with animals were the second-most common cause, accounting for 299 crashes. Other significant causes included drivers losing control (259 crashes), failure to yield from a stop sign (244 crashes), and running off the road to the left (219 crashes).

The most common first harmful event was a 'Collision with: Vehicle in traffic,' which occurred in 2,560 crashes, representing 63.1% of all incidents. A significant number of crashes involved leaving the roadway, including 290 collisions with animals and 175 collisions with a ditch. Overturns or rollovers were the first harmful event in 161 crashes.

Crashes were distributed across different parts of the road network, with a slight majority occurring outside of intersections. Non-junction segments, including driveways and alleys, accounted for 2,225 crashes. In contrast, 1,511 crashes occurred at or were related to intersections, with four-way intersections being the most common type, hosting 1,099 incidents.

Passenger cars were the most prevalent vehicle type involved in crashes, accounting for 3,485 of the 7,239 vehicles. Sport utility vehicles were the second-most common with 1,477 vehicles, followed by four-tire light trucks and pickups with 1,112. Commercial vehicles and motorcycles were also involved, with 192 tractor-trailers and 160 motorcycles recorded in crashes.

Analysis of the 6,894 vehicles with traffic control information shows that a majority were operating where no traffic controls were present (4,082 vehicles). For crashes at controlled locations, traffic signals were the most common device, present for 1,767 vehicles. Stop signs were the next most frequent control, noted for 752 vehicles involved in crashes.

The front of the vehicle was the most frequently damaged area, recorded in 1,931 instances. The rear of the vehicle was the second-most common point of impact, with 1,036 instances, which is consistent with the high number of rear-end collisions. Damage to the driver-side and passenger-side middle areas, indicative of angle or broadside collisions, was recorded in 394 and 357 cases, respectively.

A total of 181 crashes involved a driver noted for impairment, representing 4.5% of all crashes. Among these, alcohol was the most common factor, cited in 158 cases. Drugs were a factor in 17 crashes, and a combination of alcohol and drugs was noted in 6 incidents.

Crash distribution was concentrated in Iowa's most populous counties. Polk County recorded the highest number of incidents with 840 crashes, accounting for 20.7% of the statewide total. Scott County followed with 311 crashes, Linn County with 246, Johnson County with 185, and Black Hawk County with 165.

Among municipalities, Des Moines had the highest crash volume with 476 incidents. Other cities with high crash counts include Davenport with 239 crashes, Cedar Rapids with 158, and Sioux City with 146. A significant number of crashes occur in unincorporated areas and are not included in this city-level breakdown.

The vast majority of crashes, 3,832, occurred on paved roadways. However, Iowa's extensive secondary road network was also a factor, with 204 crashes, or 5.1% of the total with surface data, taking place on unpaved gravel or dirt roads.

Roadway-related factors were identified as contributors in a minority of crashes. The most common factor was 'Surface condition (e.g.wet, icy),' cited in 91 incidents. Work zone-related issues were the second-leading roadway factor, contributing to 89 crashes during this period.

Among drivers where a condition other than 'apparently normal' was noted, impairment was the most frequent. A total of 188 drivers were recorded as being under the influence of alcohol. The next most common condition was being asleep or fatigued, which was noted for 75 drivers, followed by being emotional (e.g., depressed, angry), which was recorded for 45 drivers.

The distribution of crashes across Iowa's six DOT districts shows that District 1, which includes the Des Moines metro area, had the highest volume with 1,226 crashes. District 6, covering eastern Iowa including Cedar Rapids and Davenport, recorded the second-highest number with 1,090 crashes. These two districts combined accounted for over half of all crashes in the state.

Based on officer-estimated property damage, the most common cost bracket was '$1,500 - $7,500,' which applied to 2,831 crashes. A smaller but significant number of incidents resulted in severe damage, with 105 crashes (2.6% of the total) estimated to have damage costs exceeding $25,000.

The two most common types of collisions were non-collision single-vehicle events (1,160 crashes, 28.6%) and rear-end collisions (1,125 crashes, 27.7%). Together, these two categories accounted for more than half of all reported incidents. Broadside collisions were the third-most frequent type, with 692 occurrences.

The vast majority of vehicles involved in crashes were engaged in straightforward movement. Of the vehicles with pre-crash action data, 4,058 were recorded as 'Movement essentially straight.' The next most common actions were 'Turning left' (715 vehicles) and 'Slowing/stopping' (427 vehicles).

Among the 77 recorded actions for pedestrians and bicyclists involved in crashes, the most common was 'Entering or crossing roadway,' which was noted in 48 instances. The second-most frequent action was moving along the roadway with traffic, which was recorded 10 times.

Of the 9,156 people involved in crashes, the overwhelming majority were drivers, accounting for 8,602 individuals (94.0%). Passengers made up the next largest group with 476 people. Vulnerable road users included 47 bicyclists and 24 pedestrians.

Out of 9,156 total persons involved in crashes, 1,816 suffered some level of injury or were killed. This includes 51 fatalities, 147 serious injuries, 650 minor injuries, and 968 possible injuries. The data indicates that approximately one in five people involved in a crash sustained an injury.

Among vehicle occupants for whom safety equipment use was recorded, 1,115 were reported as using a shoulder and lap belt. A concerning number, 154 individuals, were recorded as using no safety equipment at all. An additional 38 individuals, likely motorcyclists, were noted as wearing a DOT-compliant helmet.

Two-vehicle collisions were the most common type of crash, accounting for 2,608 incidents (64.2% of the total). Single-vehicle crashes were also very frequent, with 1,187 incidents, making up 29.2% of all crashes. Multi-vehicle crashes involving three or more vehicles were less common, with 224 such incidents recorded.