Iowans reap savings through statewide urban design standards and specifications

Marcia Brink
Publications Manager
Center for Transportation Research and Education
Iowa State University
Ames, Iowa

Communities in Iowa are adopting border-to-border, uniform, urban design standards and specifications, and local governments are noticing the benefits where it matters-in their pockets.

SUDAS (pronounced "soo' dahs") is the shorthand way of saying Statewide Urban Design and Specifications. Developing and maintaining Iowa's unique SUDAS manuals is the result of a lengthy and painstaking effort by more than 300 stakeholders across the state.

A brief history
In the late 1980s, 16 central Iowa urban jurisdictions, including the City of Des Moines, surrounding cities, and two counties, began meeting to discuss developing common urban standards for public improvements. Such improvements include sanitary sewers and water mains, streets and sidewalks, utility locations, signalization, drainage and erosion control, etc.

Developing common standards among several jurisdictions was breaking new ground in Iowa, and the group made slow but deliberate progress.

Their efforts came into focus in 1995 when Governor Terry Branstad assembled a Blue Ribbon Task Force on Transportation to investigate ways to use Iowa's Road Use Tax Fund more efficiently. One of the task force's recommendations was that agencies "adopt common standards for construction specifications...."

By 1998, the central Iowa group had increased to 34 Iowa jurisdictions, including several communities outside the Des Moines area, and had published a set of urban design standards and specifications. By 2000, an effort was underway to further expand the number of cities involved and to convert the published design standards and specifications to manuals that would be adopted statewide. This effort became known as the SUDAS program.

A statewide steering committee, composed of various stakeholder groups, including the Iowa Department of Transportation (DOT), cities, counties, and consultant and industry groups, was organized in 2002 to oversee the new SUDAS program. Iowa State University's Center for Transportation Research and Education (CTRE) was chosen to manage the program.

A unique little "democracy"
Keeping the SUDAS manuals current is an ongoing, cooperative effort involving hundreds of people who volunteer their time and expertise. Six district committees review proposed changes and make recommendations to the board of directors. Fourteen technical committees meet on call to discuss issues, such as traffic signals, sanitary sewers, etc.

Through metropolitan planning organizations, regional planning authorities, and transportation management agencies, Iowa's local communities are covering nearly 60 percent of SUDAS development costs. The Iowa DOT pays the balance.

Pocketing the savings
The investment is worth it. By conservative estimates, implementing urban standards statewide results in construction savings of four to seven percent. At only four percent, the annual savings to Iowans is estimated to be about $16 million—a benefit-cost ratio of 44 to one.

Here are a few examples of savings:

  • With up-to-date and uniform design standards and specifications, jurisdictions are improving their project plans and providing clearer information for contractors, which results in improved bidding.

  • Because contractors are familiar with the uniform standards, more contractors are now bidding on some individual urban projects, resulting in more competitive bids.

  • When contractors don't have to constantly change equipment and methods to meet varying specifications, they can pass on any resulting reduction in construction and maintenance costs to employing agencies.

  • Engineers save time formerly devoted to updating and, in some cases, developing new design standards and specifications for a vast number of agencies.

These kinds of results can help provide some breathing room for squeezed public works budgets.

Going corporate
To establish a mechanism for ensuring that such a valuable resource remains current and viable, the central Iowa committee transferred ownership of the SUDAS manuals to a new, nonprofit entity: the Iowa SUDAS Corporation.

The board of directors for the corporation consists of representatives from Iowa's cities and counties, the Iowa DOT, engineering consultants, and industry representatives. CTRE will continue to manage the program.

In the works
Recent major design changes include a revised sanitary sewer chapter, revised sections on traffic signals and jointing for concrete pavements, as well as a new chapter on trenchless construction and rehabilitation and a new section on HMA pavement mixture selection. Specifications changes include revised intake and manhole opening sizes, revised jointing figures, revised trench, backfill, and trenchless construction sections, revised sanitary and storm sewer sections, and revised HMA pavement section.

For future editions, SUDAS staff are reviewing the general provisions and covenants to determine the feasibility of separating technical and contractual components. Staff are also revising several elements of the manuals: asphalt surfaces specifications, various asphalt repair and rehabilitation specifications, sanitary and storm sewer structure specifications and figures, water main specifications and figures, and section covering the structural design of pipes.

An exciting future
The success of SUDAS's collaborative approach has helped it gain funding for special research projects, a few of which include the following:

Controlling stormwater runoff. SUDAS joined forces with a multi-organization Iowa Stormwater Partnership in a program primarily focused on helping local agencies comply with the Environmental Protection Agency's Phase II stormwater quality regulations.

Except where noted, the various elements of this project are funded by the Iowa Department of Natural Resources (IDNR). The elements include the following:

  • Update information regarding erosion control at construction sites in the IDNR's 1994 erosion control best management practices manual

  • Update SUDAS and Iowa DOT's design standards and specifications regarding construction site erosion and sediment control (funded by Iowa Highway Research Board [IHRB], TR-508) and stormwater quality management

  • Conduct education and outreach efforts to communities about erosion/sediment control and stormwater management, including permitting requirements for complying with phase II regulations

  • Conduct research and demonstration projects regarding urban stormwater best management practices

Preventing settlement at utility cuts. The IHRB (TR-503) is also sponsoring research to improve utility-cut repair techniques to prevent settling problems. The research team is reviewing a compilation of policies from Iowa cities, investigating backfill materials and trench geometries, and conducting onsite field tests and monitoring.

Developing a design guide for improved subgrades and subbases. Another IHRB-sponsored project (TR-525) will result in a manual to help agencies understand the properties of a good pavement support system; identify subgrade soil types and characteristics, including those of unsuitable or nonuniform materials; evaluate and select reliable foundations and treatments for moisture and density control and soil stabilization; and otherwise improve the design of subgrades and subbases.

Resolving inconsistencies between Iowa DOT and SUDAS specifications. Currently, city projects using federal-aid funds are let through the Iowa DOT with Iowa DOT specifications. The state's specifications, however, are primarily rural in nature and lack adequate guidance for municipal infrastructure. SUDAS staff are providing input and advice to a high-priority state project to resolve inconsistencies and differences between Iowa DOT and SUDAS specs.

The project involves identifying conflicting references, definitions, methods, measurements, and payment; duplicate and omitted sections; and differences between Iowa DOT and SUDAS road plans. Alternatives will be recommended to reconcile the two sets of specifications.

Resolving the inconsistencies will improve the efficiency of federally-funded city projects by increasing consistency between city and state projects and reducing the need for special provisions.

Secret of success
The effort to develop statewide design standards and specifications has succeeded because of incredibly strong stakeholder involvement and buy-in. SUDAS's unique, democratic process has proven that cross-agency cooperation can pay big dividends.

For more information
The SUDAS manuals, along with recent updates, supplementals and developmentals, are online as are forms for ordering hard copies and specific contact information for SUDAS staff. See

Marcia Brink can be reached at (515) 294-9480 or