Holiday Traffic Fatalities in Iowa 1962 to 2015, March 7, 2016

Iowa fatal crashes and fatalities for the state of Iowa in 2015.

Iowa Fatal Crashes Associated with Key Emphases - January thru December, April 15, 2015

Iowa Fatal Crashes Associated with Key Emphases - January thru December,by Iowa Dept. of Transportation - Office of Traffic and Safety

2000 Seat Belt Usage Survey, September 13, 2001

The good news is that safety belt usage on municipal road systems (city streets) increased 1.07 percent. This is encouraging since more than 45 percent of all motor vehicle crashes occur on city streets, and usage on the municipal road system has consistently been the lowest of the road systems studied. In communities where usage is good, enforcement and public education must be maintained in order to improve usage further; in communities where usage is still low, enforcement and public education must both be increased. Usage on the primary system (U.S. or state highways) rose 1.01 percent from the previous year. This is also welcome news because almost half of all fatalities (49 percent) occur on the primary road system. There was a decline in interstate belt use (-1.45 percent). Despite this decrease interstate usage is still traditionally the highest of all roadway categories presumably because the longer trips, higher travel speeds and large number of vehicles cause drivers to assume there is greater risk.

Upgrading Bridge Rails on Low-Volume Roads in Iowa, TR-679, 2016

Building on previous research, the goal of this project was to identify significant influencing factors for the Iowa Department of Transportation (DOT) to consider in future updates of its Instructional Memorandum (I.M.) 3.213, which provides guidelines for determining the need for traffic barriers (guardrail and bridge rail) at secondary roadway bridges—specifically, factors that might be significant for the bridge rail rating system component of I.M. 3.213. A literature review was conducted of policies and guidelines in other states and, specifically, of studies related to traffic barrier safety countermeasures at bridges in several states. In addition, a safety impact study was conducted to evaluate possible non-driver-related behavior characteristics of crashes on secondary road structures in Iowa using road data, structure data, and crash data from 2004 to 2013. Statistical models (negative binomial regression) were used to determine which factors were significant in terms of crash volume and crash severity. The study found that crashes are somewhat more frequent on or at bridges possessing certain characteristics—traffic volume greater than 400 vehicles per day (vpd) (paved) or greater than 50 vpd (unpaved), bridge length greater than 150 ft (paved) or greater than 35 ft (unpaved), bridge width narrower than its approach (paved) or narrower than 20 ft (unpaved), and bridges older than 25 years (both paved and unpaved). No specific roadway or bridge characteristic was found to contribute to more serious crashes. The study also confirmed previous research findings that crashes with bridges on secondary roads are rare, low-severity events. Although the findings of the study support the need for appropriate use of bridge rails, it concludes that prescriptive guidelines for bridge rail use on secondary roads may not be necessary, given the limited crash expectancy and lack of differences in crash expectancy among the various combinations of explanatory characteristics.