1,687 CRASHES IN
IOWA, IA
2015

Motor vehicle occupants accounted for the majority of individuals killed or injured, with 4 motorists killed and 408 injured. Among vulnerable road users, one pedestrian was killed and 15 were injured. While no cyclists were killed, 21 sustained injuries in traffic crashes during this period.

Crash frequencies in Story County peaked on Fridays, with 309 incidents recorded on this day of the week. The most common time for a crash was the 5 p.m. hour, which saw 177 incidents, indicating a strong correlation with the evening commute. A majority of crashes, 1,079 in total, occurred during daylight hours.

A large majority of crashes, 1,312 or 77.8%, resulted in no injuries and involved only property damage. The remaining incidents involved injuries of varying severity, including 230 crashes with possible injuries, 118 with minor injuries, and 22 with serious injuries. In total, 5 crashes were fatal, resulting in 5 fatalities during this period.

The leading contributing factor identified in Story County crashes was 'Followed too close,' cited in 253 incidents, or 15% of the total. Collisions involving animals were the second-most common factor, accounting for 207 crashes (12.3%). Failure to yield the right-of-way while making a left turn was the third leading cause, contributing to 161 crashes (9.5%).

The majority of crashes in 2015 occurred in what would be considered ideal driving conditions. Data shows that 1,079 crashes (64.0%) happened in daylight, 1,044 (61.9%) on dry road surfaces, and 959 (56.8%) in clear weather. Crashes in adverse conditions included 109 incidents during rain and 190 on wet roads, as well as 96 crashes in snow and 224 on roads with snow or ice.

Among the 3,522 people involved in crashes, individuals in the 21-25 age group were the most represented, with 711 people, followed by the 16-20 age group with 655 people. An analysis of the 3,050 vehicles involved shows that the most frequent makes were Chevrolet (548 vehicles), Ford (449 vehicles), and Toyota (335 vehicles).

The most frequently cited major cause for crashes was 'Followed too close,' which was attributed to 253 incidents (15.0%). The second leading cause was collisions with an 'Animal,' noted in 207 crashes (12.3%). 'FTYROW: Making left turn' and 'Driving too fast for conditions' were also significant factors, contributing to 161 (9.5%) and 157 (9.3%) crashes, respectively.

The most common initial event in a crash was a 'Collision with: Vehicle in traffic,' which occurred in 1,111 of the 1,687 total incidents. The second most frequent event was a 'Collision with: Animal,' recorded in 202 crashes. Other notable events included single-vehicle crashes where the first harmful event was hitting a ditch (50 crashes) or an overturn/rollover (36 crashes).

Crashes were most likely to occur on non-intersection road segments, with 682 incidents recorded in such locations. Four-way intersections were the second most common site for crashes, accounting for 442 incidents. T-intersections (130 crashes) and areas related to driveway access (100 crashes) were also frequent locations for collisions.

Of the 3,050 vehicles involved in crashes, passenger cars were the most prevalent type, accounting for 1,704 vehicles. Sport utility vehicles (SUVs) were the second most common with 571 vehicles, followed by four-tire light trucks and pickups with 373. The data also includes 50 tractor/semi-trailers and 26 motorcycles involved in crashes.

For the 3,050 vehicles involved in crashes, the most common scenario was the absence of traffic controls, which was the case for 1,610 vehicles. Where traffic controls were present, traffic signals were the most common, governing 762 vehicles involved in crashes. Stop signs were the next most frequent control type, present for 323 vehicles.

The front of the vehicle was the most common point of impact, with 822 vehicles sustaining primary damage there. A substantial number of vehicles, 455, were most damaged on their rear, which is characteristic of rear-end collisions. Various forms of side damage, impacting areas like the driver-side front (144 vehicles) and passenger-side middle (130 vehicles), were also frequently reported.

Crash data for Story County is heavily concentrated in the city of Ames, which recorded 1,106 incidents. The next most impacted municipalities were Nevada, with 75 crashes, and Huxley, with 55 crashes. These figures highlight the distribution of traffic incidents across the county's urban and town centers.

The vast majority of crashes, 1,632 out of 1,687 total, occurred on paved roadways. A total of 50 crashes were recorded on unpaved surfaces like gravel or dirt, representing approximately 3.0% of all incidents where the road surface type was specified.

In a minority of crashes where a roadway factor was deemed contributory, 'Surface condition (e.g. wet, icy)' was the most cited issue, noted in 239 incidents. Other less frequent factors included traffic backups from a prior crash (14 incidents), roadway work zones (11 incidents), and debris on the road (7 incidents).

While most drivers were recorded as 'apparently normal,' the most frequently noted contributing driver condition was being 'Under the influence of alcohol,' which was recorded for 43 drivers. The next most common conditions were being 'Asleep/fatigued,' noted for 16 drivers, and being in an 'Emotional' state, such as depressed or angry, for 13 drivers.

The most common range for estimated property damage was between $1,500 and $7,500, which was reported for 1,246 crashes. A total of 359 crashes resulted in damage estimated between $7,500 and $25,000. High-cost incidents with damage exceeding $25,000 accounted for 26 crashes, or approximately 1.5% of the total.

Rear-end collisions were the most common crash type, accounting for 497 incidents or 29.5% of all crashes. Single-vehicle, non-collision events, such as running off the road or overturning, were the second most frequent category with 415 incidents (24.6%). Broadside collisions were the third most common, occurring in 252 crashes (14.9%).

Among vehicles involved in crashes, the most common action immediately prior to the incident was 'Movement essentially straight,' recorded for 1,572 vehicles. 'Turning left' was the second most frequent pre-crash action for 319 vehicles. Other common actions included 'Slowing/stopping' (234 vehicles) and being 'Stopped in traffic' (228 vehicles).

For the 39 non-motorists involved in crashes where an action was recorded, the most prevalent behavior was 'Entering or crossing roadway,' which was documented for 35 individuals. Other actions were noted in only a few cases, including entering or exiting a vehicle and being on a sidewalk.

Of the 3,522 individuals involved in traffic incidents, the overwhelming majority were drivers, accounting for 3,388 people. The data also includes 95 passengers, 21 bicyclists, and 16 pedestrians who were involved in these crashes.

Across all 3,522 people involved in crashes, 5 individuals sustained fatal injuries. A total of 446 people were injured, with severities ranging from possible (278 people) and minor (142 people) to serious (26 people). The remaining individuals were either not injured or had an unknown injury status.

Based on a subset of 354 individuals for whom safety equipment use was documented, 324 were reported to have used a shoulder and lap belt. No safety equipment was used by 16 of these individuals. Additionally, 7 people used a DOT-compliant helmet and 3 were in a forward-facing child safety seat.

Two-vehicle collisions were the most frequent type of crash, with 1,095 incidents. Single-vehicle crashes were also common, accounting for 474 incidents, or 28.1% of the total. The data includes 118 multi-vehicle crashes involving three or more vehicles, with two notable pile-ups involving 9 and 11 vehicles respectively.