CHAPTER 5 LONG-TERM EVALUATION PROCEDURES NEEDED States are currently installing various types of protective systems on bridge decks. To validate the effectiveness of these protective systems, it will be necessary to collect and analyze performance data over their expected useful life. This will take between 10 and 35 years, depending on the protective system. Presently, the Federal Highway Administration does not have such a long-term data collection and evaluation program. It needs one. FORMAL LONG-TERM DATA COLLECTION One of the Federal Highway Administration's methods of translating research findings into standard use is through its experimental highway construction program. When an experimental item has widespread potential application, the Federal Highway Administration may formally establish a national program which assigns management responsibility for the program to its headquarters staff. Referred to as its "National Experimental and Evaluation Program," the objectives are to encourage States to construct experimental items on Federal-aid projects, and to evaluate their short-term field performance. The Federal Highway Administration established national evaluation programs for the construction of experimental bridge deck protective systems. We were told that, in general, these National Experimental and Evaluation Program studies are designed to produce quick answers on short-term trends and normally do not extend for more than 3 to 5 years. Our questionnaire confirmed the short-term nature of most of the current State studies. For example, all 28 respondents that had a moderate to very major bridge deck problem and that had ongoing studies stated that their studies would enable them to evaluate the construction feasibility and/or short-term performance of the systems. However, only three respondents said that their studies would provide a basis for evaluating the long-term effectiveness of the protective systems in achieving the design life of the bridge decks. Further, analysis of the questionnaire results showed that the evaluation timeframes for the great majority of ongoing studies is 10 years or less, with about 71 percent having a duration of 5 years or less. A total of 13 studies in five States had no specified evaluation period. Accordingly, we made followup inquiries to officials at four of the five States to determine their estimated evaluation timeframes. One State official replied that their study of one test deck would be continued until the long-term effectiveness of the system was established. Two State officials estimated that their studies could continue for about 10 years. The other State official replied that the study duration would depend upon the availability of funds and personnel. Federal Highway Administration officials stated that they have no other program for gathering any meaningful quantity of statistical data other than the National Experimental and Evaluation Program. We believe, and several Federal Highway Administration officials agreed, that a need exists for the gathering of long-term performance data to validate the engineering decisions which placed several protective systems in the experimental and standard construction categories. Both Federal and State Highway officials stated that, to validate these engineering decisions, it will be necessary to check the bridge decks having protective systems during the expected design life of the protective systems. Since the Federal Highway Administration expects the protective systems to last anywhere from 10 to 15 years for membranes, and up to 35 years for epoxy-coated reinforcing bars, a rather lengthy evaluation is needed to fully assess the effectiveness of the protective systems. The Federal Highway Administration recognizes that long-term evaluations of protective systems are needed to determine their effectiveness, but have not instituted a formal program to develop this type of data. They plan instead to rely on the States' prompt voluntary reporting of deck failures when they occur to keep abreast of this situation. CONCLUSION Weaknesses exist in the Federal Highway Administration's data collection and evaluation system which limit its capability to validate the agency's earlier engineering decisions. No long-term data collection or evaluation process currently exists, although the Federal Highway Administration recognizes the need for such a process throughout the expected useful life of the various protective systems (15-35 years). If these long- and short-term processes are not improved, efforts to develop usable performance data to resolve the deterioration problem may not be possible. RECOMMENDATION TO THE SECRETARY OF TRANSPORTATION To improve its technology evaluation process, we recommend that the Secretary establish a formal long-term data collection and evaluation system for bridge deck protective systems. AGENCY COMMENTS In a letter dated November 14, 1978 (see app. II), the Assistant Secretary for Administration, Department of Transportation, acknowledged that a formal long-term system of evaluating those bridge deck protective systems provided by research has not been initiated by the Federal Highway Administration. A program to produce a long-term data collection system for protective systems is scheduled to begin in fiscal year 1979. CHAPTER 6 SCOPE OF REVIEW We interviewed officials at Federal Highway Administration headquarters and field offices and reviewed records pertinent to the premature bridge roadway deterioration problem. We also conducted interviews and reviewed records related to bridge protective systems at the Transportation and Highway Departments in seven States. The review was made at these locations. --Department of Transportation: --Federal Highway Administration headquarters in Washington, D. C. --Federal Highway Administration regional of- --Federal Highway Administration division offices in Maryland, Michigan, Missouri, Nebraska, New Jersey, New York, and Pennsylvania. --State Transportation and Highway Departments In addition, we sent a questionnaire to the 50 States and the District of Columbia to obtain nationwide information on (1) the magnitude of the problem and (2) the current studies and future plans to evaluate the proposed solutions. did not verify the information provided to us by the States, although followup inquiries were made to clarify and amplify some of the information. |