Development of the Des Moines Access Management Plan

• Authored by:  David J. Plazak
• Co-authored by:  A. Garms , J. Rees

Plazak, D., A. Garms, and J. Rees, Development of the Des Moines Access Management Plan, prepared for the Iowa Department of Transportation, Iowa State University (2004);   [Plazak, D., A. Garms, and J. Rees, “Access Management Plan and Program for Des Moines, Iowa, Metropolitan Area,” Transportation Research Record: Journal of the Transportation Research Board, No 1981, Transportation Research Board of the National Academies, Washington, D.C. (2006); Plazak, D., A. Garms, and J. Rees, “Access Management Plan and Program for the Des Moines Metropolitan Area,” The 2005 Mid-Continent Transportation Research Symposium (2005)]  

      This project involved a cooperative effort of the Des Moines Area Metropolitan Planning Organization (Des Moines Area MPO) and the Center for Transportation Research and Education (CTRE) at Iowa State University to develop a comprehensive access management study and program for the Des Moines metropolitan area. The information was provided to assist the Des Moines Area MPO in programming and implementing access management strategies into the long range planning process. Another goal is to increase local awareness of these issues and help local officials make better decisions about access management so that future safety and operational problems can be avoided. It recommended that the Des Moines Area MPO use access management guidelines from Chapter 5 of the Iowa Statewide Urban Designs and Specifications (SUDAS) for new corridor development and suggests “best practices” for site plan reviews, with access management details, for member cities. 

      As noted in the study abstract, Iowa crash records reveal that approximately 10% of all crashes in Iowa occur at commercial driveways. Most of these crashes occur on arterials within municipalities. In recent years, nearly a quarter of these crashes have occurred in the Des Moines metropolitan area. This makes the Des Moines metropolitan area a prime candidate for improved access management. In addition, case study research in Iowa has shown that access management is an extremely effective highway safety tool and that well-managed routes are, on average, 40% safer than poorly managed routes. The Des Moines metropolitan area has many miles of four-lane, undivided arterials constructed when less was known about the importance of managing access to adjacent land development. 

      The report identified critical road segments in need of access management improvements in the Des Moines metropolitan area. Access-related issues and potential access management treatments were then provided for the critical segments, as shown in the Figures 16 and 17 below.

Figure 16. Example of corridor prioritizations

Figure 17. Example of issues and potential treatments for problem corridors.