2,358 CRASHES IN
IOWA, IA
2015

In 2015, motorists constituted the largest group of casualties, with 12 fatalities and 762 injuries. Vulnerable road users also suffered significant harm. One pedestrian was killed and 26 were injured in crashes. Additionally, while no cyclists were killed, 28 sustained injuries.

Crash patterns in Woodbury County show a distinct peak during the work week, with Friday being the most frequent day for incidents, recording 411 crashes. The afternoon commute represents the time of highest risk, as the 4 p.m. hour had the most crashes with 207 incidents. While the majority of collisions occurred during daylight hours (1,585 crashes), a significant number, 515 crashes, happened in dark conditions, both on lighted and unlighted roadways.

Of the 2,358 crashes reported, 1,628 (69%) resulted in no injuries, involving only property damage. The remaining 31% of crashes involved some level of injury, including 486 with possible injuries, 193 with minor injuries, and 39 with serious injuries. Twelve of these crashes were fatal. The 12 fatal crashes resulted in a total of 13 fatalities, indicating that at least one incident involved multiple deaths.

Severity is per crash event (most severe injury). 12 fatal crash events resulted in 13 persons killed.

Analysis of contributing factors indicates that driver error is a primary cause of crashes. The most frequently cited factor was 'Followed too close,' attributed to 271 crashes, or 11.5% of the total. Failure to yield the right-of-way from a stop sign was the second-leading cause, noted in 204 incidents (8.7%), followed by running a traffic signal, which contributed to 149 crashes (6.3%).

The majority of traffic crashes in 2015 occurred in ideal driving conditions. Data shows that 67.2% of crashes (1,585) happened in daylight, 64.6% (1,524) on dry road surfaces, and 58% (1,368) in clear weather. However, adverse conditions were also present in a notable number of incidents, with 352 crashes occurring on wet roads and 172 during rain. Another 144 crashes took place in snowy conditions.

Among the 5,261 people involved in crashes, the 26-34 age group was the most represented, with 852 individuals. Analysis of the 4,335 vehicles involved shows that Chevrolet (896 vehicles), Ford (689 vehicles), and Dodge (341 vehicles) were the most frequent makes in collisions. Toyota (238 vehicles) and Honda (217 vehicles) were also commonly involved.

The leading major cause attributed to crashes was 'Followed too close,' cited in 271 incidents. Failure to yield the right-of-way from a stop sign was the second most common cause with 204 crashes. Other significant factors included running a traffic signal (149 crashes), running off the road to the left (147 crashes), and driving too fast for conditions (140 crashes).

The most common first harmful event was a 'Collision with: Vehicle in traffic,' which accounted for 1,534 crashes, representing 65% of all incidents. Single-vehicle crashes frequently involved collisions with objects off the roadway. Notably, 133 crashes involved an animal, 53 involved a ditch, and 52 were overturns or rollovers.

The road network location of crashes was split between intersections and non-intersection segments. Approximately 49.7% of crashes (1,171) occurred at or were related to an intersection, with four-way intersections being the most common type (883 crashes). Non-junction roadway segments accounted for 845 crashes, or 35.8% of the total, while another 72 were related to driveway access.

Passenger cars were the most common vehicle type involved in crashes, accounting for 2,027 of the 4,335 vehicles. Sport utility vehicles were the second most frequent type with 1,002 vehicles, followed by four-tire light trucks and pickups with 729 vehicles. Commercial vehicles were also involved, including 83 tractor-trailers, while 33 motorcycles were recorded in crashes.

Data on traffic controls present for the 4,335 vehicles involved shows that a majority, 2,312 vehicles (53.3%), were in areas with no traffic controls present. For vehicles where controls were a factor, traffic signals were the most common, governing 1,115 vehicles. Stop signs were the next most frequent control type, affecting 555 vehicles involved in crashes.

Analysis of vehicle damage indicates that frontal impacts are the most common. The front was the most damaged area for 1,135 vehicles, while the rear was the primary point of damage for 563 vehicles, consistent with the high number of rear-end collisions. Side impacts were also prevalent, with the driver's side middle (252 vehicles) and passenger's side middle (202 vehicles) being common damage locations.

Impairment was suspected in 84 crashes, representing 3.6% of all incidents in 2015. Among the 88 instances of impairment recorded at the vehicle level, alcohol was the primary factor in 83 cases. Drugs were suspected in 3 cases, and a combination of alcohol and drugs was noted in 2 instances.

The distribution of crashes across municipalities shows a heavy concentration in Sioux City, which accounted for 2,027 of the county's 2,358 total crashes. Far smaller volumes were recorded in other communities, with Sergeant Bluff seeing 64 crashes. The towns of Moville and Sloan each recorded 14 crashes.

The vast majority of crashes occurred on paved roadways, which accounted for 2,287 incidents. Crashes on unpaved surfaces like gravel or dirt were less common, with 56 such incidents reported. This represents approximately 2.4% of the crashes where road surface type was specified.

While most crashes did not have a roadway factor cited, 'Surface condition (e.g. wet, icy)' was the most noted contributor, playing a role in 245 crashes. Work zones were the second most common roadway factor, contributing to 109 crashes. Other less frequent factors included slippery or worn surfaces (13 crashes) and traffic backups (7 crashes).

Among drivers for whom a condition other than 'apparently normal' was recorded, being under the influence of alcohol was the most cited, with 116 instances. Driver fatigue or falling asleep was noted for 16 drivers, and a medical condition such as a seizure was also recorded for 16 drivers. An emotional state, such as anger or depression, was documented for 14 drivers.

The estimated cost of property damage was most frequently in the '$1,500 - $7,500' range, which applied to 1,779 crashes, or 75.4% of the total. A smaller number of crashes resulted in more severe financial loss, with 423 incidents causing damage between $7,500 and $25,000. High-damage crashes, with costs exceeding $25,000, were relatively rare, accounting for 35 incidents (1.5%).

Rear-end collisions were the most frequent type of crash, accounting for 620 incidents or 26.3% of the total. Broadside, or front-to-side, collisions were also very common, with 541 crashes (22.9%). Single-vehicle incidents, classified as non-collisions, made up 21.7% of the total with 511 crashes.

The majority of vehicles involved in crashes were engaged in normal driving maneuvers immediately prior to the incident. Of the 4,335 vehicles, 2,585 were moving straight ahead. Turning left was the second most common pre-crash action, recorded for 397 vehicles, followed by vehicles that were legally parked (296 vehicles).

For the 59 non-motorists involved in crashes, the most common action at the time of the collision was entering or crossing the roadway, which was reported for 40 individuals. All other specified actions, such as being on the sidewalk or approaching a vehicle, were reported in much smaller numbers.

Of the 5,261 people involved in crashes, the vast majority were drivers, accounting for 5,007 individuals (95.2%). Passengers made up the next largest group with 195 individuals. The data also includes 28 bicyclists and 27 pedestrians who were involved in collisions.

Among all persons involved in crashes where an injury status was recorded, 13 suffered fatal injuries and 44 sustained serious injuries. A larger number experienced less severe outcomes, with 229 people receiving minor injuries and 547 people having possible injuries. A total of 93 individuals were confirmed to have no injuries.

Among the 694 occupants for whom safety equipment use was documented, 611 were reported to have used a shoulder and lap belt. However, 47 individuals were recorded as using no restraint at all. Child safety seats were used by 13 occupants, including 10 in forward-facing seats.

Two-vehicle collisions were the most common scenario, accounting for 1,665 crashes, or 70.6% of all incidents. Single-vehicle crashes were the next most frequent type, with 550 incidents, making up 23.3% of the total. Multi-vehicle pile-ups involving three or more vehicles were less common, with 120 crashes involving three vehicles and 20 involving four.