Implementation of bridge system underway

Last October, Iowa finalized plans for the implementation of a statewide bridge management system (BMS) that will collect, store and analyze inventory and condition data and help establish histories for all public bridges in the state. Ultimately, the information will be used in financial analyses and in determining optimal bridge maintenance, repair and replacement strategies.

Developed by the Iowa Bridge Management Technical Committee (BMTC) at the Iowa Department of Transportation, the plan encompasses nearly 26,000 bridges. Bruce Brakke, BMTC chairman and bridge maintenance engineer for Iowa DOT, reports that the system should be fully operational by October 1998.

BMTC has already selected software for the project. According to Technology News, a publication of Iowa State University’s Transportation Center, Iowa will use PONTIS, a program developed in 1992 by the state of California under a contract with the Federal Highway Administration (FHWA).

Data gathering for state-owned bridges is under way as part of Iowa DOT’S regular bridge inspection process. For structures owned by cities and counties, a consultant has been retained to:

* identify commonly recognized (CORE) elements for which condition data must be collected,

* determine performance (deterioration rates) and cost data for each CORE element,

* train city and county personnel, including private consultants, in data-collection requirements and techniques,

* produce revised data-collection forms,

* produce a bridge inspection manual and other aids for city and county personnel, and

* provide follow-up support to cities and counties through 1996. Input will be solicited from cities and counties regarding appropriate performance and cost data for each CORE element. In addition, the consultant will train city, county and private-sector bridge personnel in inspection procedures for PONTIS.

Data required for the BMS will supplement rather than replace data collected for the FHWA as part of the National Bridge Inventory (NBI). For example, the FHWA requires condition rating for a bridge’s deck, superstructure and substructure. Under the BMS, these three parts will be separated into eight to 10 CORE elements, and conditions for these elements will be recorded.

The consultant will revise NBI inspection forms to accommodate data required for PONTIS. The initial BMS inspection will take longer than the NBI inspection alone, but subsequent recordings should take little extra time.

Iowa DOT participated in the beta tests for PONTIS and is already familiar with its capabilities. BMTC expects the program to:

* provide a reliable basis for evaluating bridge maintenance, repair and replacement strategies;

* provide reliable estimates of current and forecasted bridge conditions; and

* aid in financial analyses. For example, the current method for deciding the optimum time to treat bridge problems is generally to fix the worst problems first. PONTIS will look at the “condition cost” and compute the optimal least costly time to do particular kinds of work over the life of each bridge.

PONTIS also can predict the condition of all bridges within set funding limits and can determine how much funding is required to maintain all bridges at a certain level, analytical abilities essential for maintaining to, day’s transportation infrastructure, says Marlee Walton, BMTC member and Iowa DOT transportation engineer.

“We’re in an era of preservation and maintenance rather than building new,” she says. “Our goal is to maintain bridges as efficiently as possible, and to do that we need to know the optimal timing and optimal funds for maintenance and repair work.”