Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil and Environmental Engineering

First Advisor

Michael D. Pawlovich


2005, Increases, Iowa, Linear Regression, Rural Interstates, Speed Limit


Speed limit increases, particularly on interstates have been studied and researched many times over the course of the last 50 years in the United States. These research efforts began after the implementation of the National Maximum Speed Law (NMSL), which reduced all speed limits to a maximum of 55-mph. In the years that followed, this restriction was relaxed to 65-mph with the Surface Transportation and Uniform Relocation Assistance Act (STURAA) and ultimately repealed later by the National Highway System Designation Act (NHSDA). Since the repeal, states reacted in myriad of ways and many studies documented the changes of those reactions. While these efforts have investigated the changes in the fatality and crash rates before and after a speed limit increase, many additional crash data fields are available for research. The primary goal of the research detailed in this thesis was to consider available crash, road, and traffic data more broadly. The data used was obtained from the State of Iowa to observe the 2005 rural interstate speed limit increase from 65-mph to 70-mph.

Library of Congress Subject Headings

Speed limits -- Iowa.
Traffic accidents -- Iowa -- Statistics.
Traffic safety -- Iowa.
Regression analysis.



Number of Pages



South Dakota State University



Rights Statement

In Copyright