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48 CHAPTER SIX CONCLUSIONS Bridge inspections are performed for at least three reasons: might be as cursory as drive-by inspections. Medium-interval (1) to ensure the safety of bridges, (2) to discover needs in inspections often require that inspectors be able to view all maintenance and repair, and (3) to prepare for bridge reha- bridge components, whereas long-interval inspections re- bilitation. These three reasons produce three levels of in- quire hands-on access. U.S. federal regulations require spection: (1) short-interval checks of safety, (2) medium- hands-on inspection of fracture-critical members, but oth- interval reviews of maintenance needs, and (3) long-interval erwise allow inspectors to determine which bridges or por- assessments of needs for major work. tions of bridges need hands-on inspection. Some U.S. state DOTs have policies that require hands-on inspection at spe- U.S. federal regulations provide at least two levels of in- cific details, for specific conditions, or within specific max- spections; interim inspections that are short-interval and detail- imum intervals. specific, and routine inspections that are medium-interval and full-extent. Routine inspection at 48-month intervals is In foreign practice, depending on interval, inspections applied to a few robust bridges in good condition. The poli- may collect few condition ratings, all condition ratings or all cies of U.S. state departments of transportation (DOTs) often condition ratings plus field measurements, results of materi- provide three levels of inspection: (1) short-interval interim als tests, or other quantitative data (Table 80). U.S. federal inspections; (2) medium-interval routine inspections; and (3) regulations require updates to National Bridge Inventory longer-interval, in-depth, close-access, or increased-intensity (NBI) data at each routine inspection. For most U.S. bridges, inspections for at least some bridges or details. this entails a complete set of NBI condition ratings plus any changes to appraisal ratings and inventory data at 24-month In foreign practice, frequent, less-detailed inspections are intervals. used together with a long-interval Principal or Major inspec- tions. Of the countries studied, three employ short-, medium-, In foreign practice, recommendations for work at and long-interval periodic inspections for bridges, and nearly bridges range from superficial maintenance needs noted for all identified noninterval special or project-level inspections the most frequent inspections, to complete identification of for repair projects (Table 77). repair needs during inspections at medium intervals, to de- tailed recommendations of actions, quantities, and costs at Inspection types in U.S. and in foreign practices can be long intervals (Table 81). In U.S. practice, maintenance compared in terms of inspector qualifications, inspection recommendations are updated every 24 months for most intensity, repair recommendations, and inspection program bridges. control. Table 78 cites the qualifications of inspectors required for each type of inspection. In foreign practice, inspections at In foreign practice, authority for inspections is usually 12-month or shorter intervals are done by maintenance fore- shared between two branches of a road agency, or between a men or other capable, noncertified personnel. Inspections at road agency and its maintenance contractors. The most fre- medium intervals require certified bridge inspectors. Long- quent inspections are done by maintenance crews and interval inspections demand degreed engineers who are also reported to agencies' bridge inspection programs (Table 82). certified bridge inspectors. U.S. federal regulations establish a Inspections that require certified inspectors and occur at single personnel level, a team leader, and require this level for longer intervals are directly administered by agencies' in- all inspections. U.S. team leaders need not be engineers. spection programs. U.S. federal regulations require team leaders for all inspections, with the result that administration Inspection intensity varies with inspection interval of all inspection work remains within a DOT's inspection (Table 79). In foreign practice, short-interval inspections program using either DOT staff or inspection consultants.

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49 TABLE 77 BRIDGE INSPECTIONS Inspection South United Interval U.S. Denmark Finland France Germany Norway Africa Sweden Kingdom 3 months Superficial Superficial 1 year Routine Annual Annual General Monitoring Superficial 2 year Routine General 3 year IQOA Minor General 4 year Routine 48-month 5 year General Major Principal 5-year 6 year Principal Detailed Major Major Principal 7 year 8 year General 8-year 10 year In-depth 120-month For Project Special Economic Special Special Special Project-level Special Special Special IQOA = Image de la Qualit des Ouvrages dArt. TABLE 78 INSPECTORS AND INSPECTIONS South United Personnel U.S. Denmark Finland France Germany Norway Africa Sweden Kingdom Non-Certified Routine Annual Annual Superficial General Monitoring Superficial Superficial Inspector Agency Routine General IQOA Minor General Certified 5-year Inspector Routine General Detailed 48-month 8-year In-depth 120-month Engineer Principal Basic Major Major Principal General Principal Economic Special Special IQOA = Image de la Qualit des Ouvrages d'Art. TABLE 79 INSPECTIONS AND INTENSITY Inspection South Access U.S. Denmark Finland France Germany Norway Africa Sweden United Kingdom Drive-By Daily Routine Routine Visible Routine Routine Annual Minor General Monitoring Superficial Superficial Routine Principal IQOA General General 48-month Arms Length In-depth General Detailed Major Major Principal Major Principal* 120-month 5-year* *Said to be "arms-length," but traffic lane closures are rarely provided. IQOA = Image de la Qualit des Ouvrages d'Art. TABLE 80 INSPECTIONS AND CONDITION DATA Condition South United Data U.S. Denmark Finland France Germany Norway Africa Sweden Kingdom None or Few Routine Annual Minor General Monitoring Superficial Superficial All Condition Routine Principal General IQOA Major Principal General General Ratings 5-year Detailed Major Principal Tests and Special General Special Major Project- Special Special Measurements 8-year level IQOA = Image de la Qualit des Ouvrages d'Art.

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50 TABLE 81 INSPECTIONS AND MAINTENANCE AND REPAIR RECOMMENDATIONS South United Actions U.S. Denmark Finland France Germany Norway Africa Sweden Kingdom Cleaning Routine Annual Annual Minor General Monitoring Superficial Superficial IQOA General General All Routine Principal General Detailed Major Major Principal Major Principal Actions 5-year General 8-year Costs and Special Economic Special Special Special Project- Special Quantities Special level IQOA = Image de la Qualit des Ouvrages d'Art. TABLE 82 INSPECTIONS AND SUPERVISION BY INSPECTION PROGRAM Inspection South United Program U.S. Denmark Finland France Germany Norway Africa Sweden Kingdom Partial or Daily Annual Routine Superficial Monitoring Superficial Superficial No Control Routine Annual Primary Routine Principal General IQOA Minor General Principal General General Control 5-year Routine General Detailed Major Major Major Principal 48-month 8-year In-depth Economic Special Special Project- Special Special 120-month Special level IQOA = Image de la Qualit des Ouvrages d'Art.