Comparison Between Leaded and Nonleaded Gasoline as Used in Iowa State Highway Commission Vehicles, HR-1002, 1972

The overall objective of this experimental program was to obtain quantitative comparisons between leaded and nonleaded gasolines as used in a variety of Iowa State Highway Connnission vehicles. These quantitative comparisons were to be made in terms of exhaust emissions, maintenance costs and fuel economy.

Flex Fuel Vehicles, 2011

Registered FFVs Effective 1/2011

Flex Fuel Vehicles, 2012

Registered FFVs Effective 1/2012

Flex Fuel Vehicles, 2013

Registered FFVs Effective 1/2013

Flex Fuel Vehicles, 2014

Registered FFVs Effective 1/2014

Iowa Motor Vehicle Crashes 1925 to 2014

Iowa motor vehicle crashes spreadsheet, years 1925-2014

Dynamic Simulation Methods for Evaluating Motor Vehicle and Roadway Design and Resolving Policy Issues, 1990

This study had three objectives: (1) to develop a comprehensive truck simulation that executes rapidly, has a modular program construction to allow variation of vehicle characteristics, and is able to realistically predict vehicle motion and the tire-road surface interaction forces; (2) to develop a model of doweled portland cement concrete pavement that can be used to determine slab deflection and stress at predetermined nodes, and that allows for the variation of traditional thickness design factors; and (3) to implement these two models on a work station with suitable menu driven modules so that both existing and proposed pavements can be evaluated with respect to design life, given specific characteristics of the heavy vehicles that will be using the facility. This report summarizes the work that has been performed during the first year of the study. Briefly, the following has been accomplished: A two dimensional model of a typical 3-S2 tractor-trailer combination was created. A finite element structural analysis program, ANSYS, was used to model the pavement. Computer runs have been performed varying the parameters defining both vehicle and road elements. The resulting time specific displacements for each node are plotted, and the displacement basin is generated for defined vehicles. Relative damage to the pavement can then be estimated. A damage function resulting from load replications must be assumed that will be reflected by further pavement deterioration. Comparison with actual damage on Interstate 80 will eventually allow verification of these procedures.

Project Evaluation: Iowa Motor Vehicle Fuel Reduction Program, 1989

The results of a study which evaluates the Iowa Motor Vehicle Fuel Reduction Program have been summarized and described in this report. The Iowa Motor Vehicle Fuel Reduction Program was designed to demonstrate fuel savings through traffic signal modernization projects and provide direct benefits to motorists in Iowa.

Investigation of the Impact of Dual-Lane Axle Spacing on Lateral Load Distribution, 2016

The spacing of adjacent wheel lines of dual-lane loads induces different lateral live load distributions on bridges, which cannot be determined using the current American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) or Load Factor Design (LFD) equations for vehicles with standard axle configurations. Current Iowa law requires dual-lane loads to meet a five-foot requirement, the adequacy of which needs to be verified. To improve the state policy and AASHTO code specifications, it is necessary to understand the actual effects of wheel-line spacing on lateral load distribution. The main objective of this research was to investigate the impact of the wheel-line spacing of dual-lane loads on the lateral load distribution on bridges. To achieve this objective, a numerical evaluation using two-dimensional linear elastic finite element (FE) models was performed. For simulation purposes, 20 prestressed-concrete bridges, 20 steel bridges, and 20 slab bridges were randomly sampled from the Iowa bridge database. Based on the FE results, the load distribution factors (LDFs) of the concrete and steel bridges and the equivalent lengths of the slab bridges were derived. To investigate the variations of LDFs, a total of 22 types of single-axle four-wheel-line dual-lane loads were taken into account with configurations consisting of combinations of various interior and exterior wheel-line spacing. The corresponding moment and shear LDFs and equivalent widths were also derived using the AASHTO equations and the adequacy of the Iowa DOT five-foot requirement was evaluated. Finally, the axle weight limits per lane for different dual-lane load types were further calculated and recommended to complement the current Iowa Department of Transportation (DOT) policy and AASHTO code specifications.

Licensed Iowa Drivers by County 2007-2015, January 29, 2016

Licensed Iowa drivers by county spreadsheet.

Iowa Crash History 2001 to 2015: Drivers Distracted by Use of Phone or Other Device, May 11, 2016

Iowa crash history of distracted drivers by use of phone or other devices.

2015 Iowa Fatal Crashes and Fatalities, May 25, 2016

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

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

Licensed Iowa Drivers by by Age Group & Sex - 2007 to 2015, January 29, 2016

Licensed Iowa drivers by age ground and sex spreadsheet.