Multimodal Investment Analysis Methodology, Phase One: The Conceptual Model, 1998

The purpose of this project is to develop an investment analysis model that integrates the capabilities of four types of analysis for use in evaluating interurban transportation system improvements. The project will also explore the use of new data warehousing and mining techniques to design the types of databases required for supporting such a comprehensive transportation model. The project consists of four phases. The first phase, which is documented in this report, involves development of the conceptual foundation for the model. Prior research is reviewed in Chapter 1, which is composed of three major sections providing demand modeling background information for passenger transportation, transportation of freight (manufactured products and supplies), and transportation of natural resources and agricultural commodities. Material from the literature on geographic information systems makes up Chapter 2. Database models for the national and regional economies and for the transportation and logistics network are conceptualized in Chapter 3. Demand forecasting of transportation service requirements is introduced in Chapter 4, with separate sections for passenger transportation, freight transportation, and transportation of natural resources and commodities. Characteristics and capacities of the different modes, modal choices, and route assignments are discussed in Chapter 5. Chapter 6 concludes with a general discussion of the economic impacts and feedback of multimodal transportation activities and facilities.

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.

2015 Iowa Traffic Fatality Count, March 31, 2016

A fatality is considered "crash-related" when death occurs within 30 days of a crash. Because complex crash investigations can delay the official report of fatalities, the numbers for the most current months are preliminary and can change considerably.

Iowa Vehicle Registrations Statistics, January 1, 1998

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation

Iowa Vehicle Registrations Statistics, January 1, 1999

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation

2000 Vehicle Registrations Summary, May 23, 2001

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation

2001 Vehicle Registrations Summary, June 7, 2002

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation

2004 Vehicle Registrations Summary, December 22, 2005

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation

2005 Vehicle Registrations Summary, March 5, 2008

Iowa vehicle registration statistics by county and vehicle type produced by Iowa Department of Transportation