CTRE is an Iowa State University center, administered by the Institute for Transportation.

Address: 2711 S. Loop Drive, Suite 4700, Ames, IA 50010-8664

Phone: 515-294-8103
FAX: 515-294-0467

Website: www.ctre.iastate.edu/

Iowa State University--Becoming the Best

Improving Safety for Slow Moving Vehicles on Iowa's High Speed Rural Roadways

Horse drawn vehicle

Horse drawn vehicle on a public road in Davis County, Iowa


Principal investigators:

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Project status


Start date: 06/01/07
End date: 11/30/08


Report: Improving Safety for Slow Moving Vehicles on Iowa's High Speed Rural Roadways (12.9 mb pdf) May 2009


Sponsor(s): Iowa Department of Transportation

About the research

Abstract: Among the variety of road users and vehicle types that travel on U.S. public roadways, slow moving vehicles (SMVs) present unique safety and operations issues. SMVs include vehicles that do not maintain a constant speed of 25 mph, such as large farm equipment, construction vehicles, or horse-drawn buggies. Though the number of crashes involving SMVs is relatively small, SMV crashes tend to be severe. Additionally, SMVs can be encountered regularly on non-Interstate/non-expressway public roadways, but motorists may not be accustomed to these vehicles.

This project was designed to improve transportation safety for SMVs on Iowa?s public roadway system. This report includes a literature review that shows various SMV statistics and laws across the United States, a crash study based on three years of Iowa SMV crash data, and recommendations from the SMV community.