National Academies Press: OpenBook

State Bridge Load Posting Processes and Practices (2014)

Chapter: Chapter Two - Management of Load Posting of Bridges and Culverts

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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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Suggested Citation:"Chapter Two - Management of Load Posting of Bridges and Culverts ." National Academies of Sciences, Engineering, and Medicine. 2014. State Bridge Load Posting Processes and Practices. Washington, DC: The National Academies Press. doi: 10.17226/22412.
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15 chapter two MANAGEMENT OF LOAD POSTING OF BRIDGES AND CULVERTS Chapter two reports on state government authority to post structures for load, the role of state government in load post- ing of structures owned by local governments, load rating staff at DOTs, use of safety inspections and general condition ratings in load posting, time intervals to identify and imple- ment load postings, quality practices in load posting, signs for weight limits at posted structures, and fines for violation of weight limits. The content of this chapter is summarized here: Authority to Post for Load State governments have the authority to post state-owned bridges and culverts for load. In general, local governments retain the authority to post their structures for load. In some states, the state DOT inspects, evaluates, and posts local government structures; in others, the state DOT can load post local government struc- tures if the local government fails to implement needed posting. State governments have the responsibil- ity under federal regulation to ensure that all bridges and culverts, both state structures and local government structures, are inspected, load rated, and, if necessary, load posted. States often assist local governments in safety inspections and load ratings. Load Rating Staff Most states complete all or most evaluations of load ratings using DOT staff. States that use engineering consultants for load ratings perform quality reviews of consultants’ work Safety Inspections Safety inspections can reveal changes to bridges and culverts that affect load capacity. Findings of inspections can prompt re-evaluation of load ratings with load posting among the possible outcomes. Safety inspectors can recommend re- evaluation of load ratings. DOT load rating engineers can review inspection reports and re-evaluate load ratings as needed. Some DOTs have policies to re-evaluate load ratings when general condition ratings are low or have declined significantly. Safety inspections provide quantitative data that are used in evaluations of load ratings. Data can include thicknesses of wearing courses on decks and dimensions of remaining sections of deteriorated components of structures. Time Intervals Time intervals for tasks in load posting vary from immediate action to restrict live loads when safety is impeached, to several weeks that state DOTs may allow local government bridge owners to implement load posting, to one year or more for verification of weight limit signs as a part of periodic safety inspections. Statutory and regulatory time limits exist for actions by local governments and for updates to bridge databases when load rating or post- ing status changes. Policy limits on time exist at some DOTs for various branches to act on inspection findings that affect load ratings. In all states, there is prompt action for events and findings that affect the safety of structures. Quality Practices Quality control and assurance for load post- ings are achieved through quality programs for safety inspections and for load ratings. States use peer review of load rating computations, review of computer models and modeling assumptions, and hand computations to verify outputs of software applications for load rating. Weight Limit Signs Most states use U.S.DOT standard signs for weight limits at posted structures. Some states use additional, state-specific signs for weight limits. Overweight Fines The median fine for violation of weight limits is $0.20 per pound of excess weight. The range of fines is $0.01 per pound to $0.75 per pound. Most states have schedules of fines that impose greater fines for greater excess weight. Information presented in chapters two and three was col- lected from a survey of states on load posting practices, state statutes, state administrative codes, and DOT publications such as bridge rating manuals, bridge inspection manuals, and trucker’s handbooks. Where information from the survey is used, this is noted as “response to Survey” or as information from “Survey states.”

16 mend posting for load. In Illinois, the state DOT, acting at the request of a local authority or acting on its own, can deter- mine and post weight limits on structures that are part of a mainline highway (9). The Maryland State Highway Admin- istration is responsible for load posting of all structures (10). Missouri law allows cities or counties to delegate authority for load posting to the state (11). Missouri places the authority to post for load in a state Transportation Commission. Nebraska law designates the DOT director as the custodian of the state highway system, and vests the director with the authority to establish proce- dures for all design, construction, maintenance, and operation of highways and structures (12). State laws in New Hampshire (13) and in Nevada (14) place the authority to post weight limits with DOT directors. Survey responses on the authority to post for load appear in Table A2. LOAD RATING STAFF Sixteen states use only DOT staff to evaluate load ratings, 18 states complete more than 50% of load ratings using DOT staff, and nine states use engineering consultants for most load ratings (Table 33). Texas uses consultants for most load ratings, and uses state DOT staff to check all load ratings that result in recommen- dations to post for load. Idaho is using consultants at present (year 2013) to resolve a backlog of load ratings. By 2014, the Idaho Transportation Department will perform most load ratings with state employees. Idaho makes quality reviews of all load ratings by consultants. Survey response on staff for load rating is listed in Table A3. Forty-three U.S. states responded to the survey. Where counts of states are reported for various aspects of load post- ing practice, these are the counts from the 43 survey states. In this synthesis report, New York State and its DOT are referred to simply as “New York.” No information is presented from the New York City DOT. Washington State and its DOT are referred to as “Washington.” This synthesis presents no information from the District of Columbia DOT. This report identifies U.S. government sources as “U.S.,” “U.S.DOT,” or “federal.” Details on practices from individual U.S. states are based on state publications and on longer responses to the ques- tionnaire provided by some states. The selection of details follows the available information from states. AUTHORITY TO POST FOR LOAD Background For state-owned bridges and culverts, the state DOT evalu- ates safe load capacities and determines needs to post struc- tures for load. In 36 survey states, authority to post for load is held in the DOT central office by the state bridge load rater, state bridge engineer, DOT chief engineer, or DOT director (Table 31). In seven states, authority is held at the DOT dis- trict level or by other state official. In 14 survey states, the authority of the state DOT extends to load posting of some structures owned by local govern- ments (Table 32). Notes on State Authority in Posting Bridges and Culverts In Alabama, the authority of the state DOT to post for load extends to any bridge or culvert that is built or maintained with state funds (7). In Florida, the state DOT can impose weight limits at local government structures if local govern- ments fail to impose needed limits (8). Local governments in Florida have 30 days to act on inspection reports that recom- Authority to Post States Count DOT Director/Secretary of Transportation 9 DOT Chief Engineer 6 State Bridge Engineer 15 State Bridge Load Rating Engineer 6 DOT District Engineer 5 Other 2 TABLE 31 SUMMARY—STATE AUTHORITY TO POST FOR LOAD Structures Posted by State DOT States Count All Structures 14 State-Owned Structures Only 29 TABLE 32 SUMMARY—STATE’S SCOPE OF LOAD POSTING Load Rating Execution States Count State Performs All Load Ratings 16 State Performs Most Load Ratings 18 Consultants Perform 50% or More Load Ratings 9 TABLE 33 SUMMARY—EXECUTION OF LOAD RATINGS

17 inspection coordinators of damage or safety concerns (21). New York re-calculates an H20 operating rating for each bridge as part of biennial inspection. A low operating rating triggers a detailed review for (potential) load posting (22). Ohio’s district bridge engineers request re-evaluation of load ratings. District engineers use Ohio’s general appraisal ratings and reports of structural deficiencies in making requests (23). Oregon reviews inspection reports for conditions of struc- tures and for inspectors’ comments that indicate potential changes to load capacity. A drop in condition rating of 2 or more for primary load carrying members triggers re-rating (24). Oregon uses queries to its bridge database to find poor conditions or changes to condition, and to alert the load rating staff. In Texas, professional engineers (PEs) review all reports of safety inspections and determine whether to re-evaluate load capacity. Virginia requires that district bridge engineers determine the need for re-rating as part of routine safety inspections (25). The state responds to critical findings to ensure the safety of road users. This response can include re-rating of highway structures. Washington’s Bridge Preservation Office exam- ines bridge inspection reports and identifies bridges that must be re-rated for load (26). In Wisconsin, bridge inspectors can set a re-rate flag in the DOT’s Highway Information System to schedule a load rating of a structure (27). States’ comments on use of safety inspection reports and responses to critical findings are noted in Table A5. USE OF GENERAL CONDITION RATINGS IN LOAD POSTING Background Low values of GCR indicate deterioration that may affect load capacity. Twenty-two states reported values of GCRs that trigger re-evaluation of load ratings. NBI GCR ‘4’ is the most common value to prompt re-rating (Table 35). Sixteen states re-rate for a low deck condition rating, 21 for a low super- structure condition rating, 17 for a low substructure condition rating, 13 for a low culvert condition rating, and three for a low channel condition rating. Survey responses on the use of NBI GCRs to re-evaluate load ratings for bridges and culverts are shown in Table A6. Notes on General Condition Ratings and Re-evaluation of Load Ratings Florida assumes that decks in poor condition are simple spans between girders and evaluates distribution factors for live load using this assumption (18). Illinois re-rates when NBI GCRs drop to 4 or lower (29). Indiana requires that bridge inspectors notify load raters whenever NBI GCRs fall to 5 or below for primary load USE OF SAFETY INSPECTIONS IN LOAD POSTING Background State DOTs review reports of safety inspections for changes at bridges and culverts that may affect load capacity. Changes include additions to dead weight, changes to condition, and critical findings. The use of inspection reports in decisions to re-evaluate load capacity of structures is shown in Table 34. In 28 states inspectors can recommend the re-evaluation of load ratings, in 11 states load rating staff review inspection reports, in 16 states an initial report of low general condi-tion rating can trigger a re-evaluation of load rating, and in 39 states report of a critical finding can trigger a re-evaluation of load rating. Survey responses on the use of safety inspections in load posting are listed in Table A4. Response on use of critical findings is listed in Table A5. Notes on States’ Use of Bridge Safety Inspection Reports in Load Posting In Arizona, inspection reports are checked in quality con- trol, and the checker identifies issues in the report that may affect load capacity (15). Colorado re-evaluates load ratings for critical findings and uses inspection reports to verify the thickness of hot-mix bituminous pavement wearing surfaces on bridge decks; Colorado’s inspection program manager requests re-evaluation of load ratings as needed (16). Dela- ware re-evaluates load ratings when section loss in members is reported (17). In Florida, DOT districts review each inspec- tion report and determine whether current load ratings are consistent with newly reported conditions. Florida re-rates on critical findings, if findings affect load capacity (18). Indiana relies on inspection team leaders to decide whether a re-evaluation of load rating is needed. Team leaders also track and verify the completion of computations by bridge load raters (19). In Louisiana, the load rating engineer reviews bridge files after every inspection and determines whether a new load rating analysis is required (20). Maryland re-rates for all significant new deterioration and for critical findings in primary structural components. In Montana, bridge inspectors notify DOT district bridge Safety Inspections and Load Posting States Count Inspectors Recommend Re-Rate 28 Load Raters Review Inspection Reports 11 Low General Condition Rating Triggers Review 16 TABLE 34 SUMMARY—USE OF SAFETY INSPECTIONS IN LOAD POSTING

18 TIME INTERVALS FOR LOAD POSTING Background The time interval from an initial recommendation to consider load posting to the installation and verification of weight limit signs ranges from less than one week to more than one year (see Table A7). Recommendations for re-rating, and verifi- cation of weight limit signs are both part of routine safety inspections, and therefore the time interval for verification of signs can be linked to the interval for inspection. During the time from initial recommendation, to re-evaluation of load capacity, to a decision to post for load, DOTs review options for immediate repair, for exclusion of permit vehicles, or for load posting. States respond quickly to situations of severe damage to structures and to other events that could danger- ously decrease load capacity. Responses of survey states on time intervals are noted in Table A8. When load ratings are changed, federal regulation requires updates to bridge inventory records within 90 days for state- owned structures and within 180 days for local government structures (35). These limits appear in states’ policies for completion and reporting of load ratings (Table 37). State policies also set time limits on the state’s response to rec- ommendations to post for load, and time limits on response by local governments to advice from the state to post structures for load. Time intervals differ for state and locally owned struc- tures. State DOTs act autonomously for load posting of state- owned structures. DOTs, in many states, lack authority to post local government structures. Instead, state DOTs notify local bridge owners of the need to re-evaluate load capacity or need to post for load. State DOTs can act only if, and only after, local owners fail to act. Notes on Time Intervals Florida has a statewide bridge database that contains load rat- ings and other bridge information. District quality control (QC) processes must track the date(s) when re-evaluation of load ratings of structures is (1) recommended and (2) completed. carrying members (19). Louisiana requires consideration of load posting when the NBI GCR for primary load carrying members is 3 or below (30). Louisiana uses GCRs to set inter- vals for continuing re-evaluation of load ratings (20) (Table 36). Nevada requires load rating of reinforced concrete girders and reinforced concrete pier caps when NBI GCRs are below 6. It uses reduced material properties in load rating computa- tions for components with GCR lower than 6 (31). New York identifies bridges for “R-Posting”; an exclusion of overweight permit loads when a primary member has a New York GCR of less than 4, or a deck has a New York GCR equal to 1. New York uses a 7-valued condition rating scale. Rating 7 is an as-new condition; rating 4 is deficient (32). Oklahoma uses a four-value element-level condition rating scale. Element condition ‘1’ is good; element condition ‘4’ is poor. Load ratings are re-evaluated when condition ratings for deck, superstructure, or substructure drops to ‘4’ or drops by two or more rating points in a single inspection (33). Oklahoma’s electronic bridge inspection reports include a field that inspectors use to recommend re-evaluation of load ratings. Utah re-rates bridges when the superstructure condition rating is 4 or lower, or when the superstructure condition rating drops by 2 or more (34). Washington uses a four-value element-level condition reporting scale (26). Element con- dition ‘1’ is good; element condition ‘4’ is poor. Re-rating is advised when conditions of primary load carrying elements drop from condition state 1 or 2 to condition state 3 or 4. GCR Triggers Load Rating States, Count States (any component) Deck Superstructure Substructure Channel Culvert 5 1 1 1 — 2 2 4 11 17 14 1 9 18 3 3 3 2 2 2 6 2 1 — — — — 1 States (any GCR) 16 21 17 3 13 TABLE 35 SUMMARY—GENERAL CONDITION RATINGS (GCR) AND RE-EVALUATION OF LOAD RATING Lowest GCR Re-Rating Interval, years 0–2 2 3–5 10 6–9 — TABLE 36 LOUISIANA GENERAL CONDITION RATINGS AND INTERVALS FOR LOAD RATING

19 load rating computations. Many states collect photographs of weight limit signs at structures as verification of load post- ing. Signs for weight limits are verified during routine safety inspections of structures. States’ quality practices for load posting were collected from the survey and from state bridge program manuals. The terms quality control (QC) and quality assurance (QA) are used as the individual states apply these terms. This synthesis report does not alter states’ use of terms. Load Rating Quality Peer review of load ratings addresses the use of reports from safety inspections to determine dead loads and to identify and evaluate deteriorated components; formation of appropri- ate models for load rating analysis; and application of DOT policy for consideration of condition, load path redundancy, traffic levels and other aspects of structure type, condition or service that affect load ratings, and load postings. Notes on States’ Quality Practices Arizona requires peer review of load rating computations (15). Both the load rater and the reviewer sign the load rating Louisiana’s central office bridge design section advises DOT districts of the need to post structures for load. Districts must act on the advice within 30 days, and report on their actions to the bridge design section (20). New York reports that bridge condi- tion and load path redundancy affect the urgency of evaluation for load posting. New York acts on posting within one day for the most urgent cases, and within 6 weeks for less urgent cases. Oregon completes implementation of load posting within 6 months of load rating. Virginia applies immediate restrictions on bridge live loads if changes to condition or dead weight are significant. The immediate restrictions can exclude overweight permit vehicles while evaluations for load posting are com- pleted. In Wisconsin, the bridge load rating engineer makes immediate review of recommendations to re-evaluate load capacity, and determines a priority for each recommendation. QUALITY PRACTICES IN LOAD POSTING Quality practices in load posting include: (1) Detection of struc- tures that should be re-rated, (2) confirmation of the accuracy of load rating computations, and (3) verification that load post- ing signs are installed. Quality practices for safety inspec- tion programs address concerns in detection of structures to re-rate. Most states apply peer review for confirmation of State Milestones Bridges Interval Days Colorado (16) Safety inspection1 to Updated load rating2 State owned 90 Florida (18) Safety inspection to Updated load rating Simple bridges 60 Safety inspection to Updated load rating Complex bridges 90 Updated load rating to Bridge database3 On system 90 Updated load rating to Bridge database Off system 180 Louisiana (20) Updated load rating Posting implementation5 State owned 30 Michigan (36) Updated load rating to Posting implementation State owned 90 Updated load rating to Posting implementation Locally owned 180 Minnesota (37) Updated load rating to Posting implementation All 30 Ohio (38) Updated load rating to Bridge database State owned 90 Updated load rating to Bridge database Locally owned 180 Oregon (24) Updated load rating to Bridge database State owned 90 Updated load rating to Bridge database Locally owned 180 Texas (39) Notification to owner4 to Posting implementation State owned 90 Notification to owner to Posting implementation Locally owned 180 Washington (26) Notification to owner to Posting implementation All 60 Milestones: 1Safety inspection—Submission of signed inspection report containing a recommendation to re-rate or to post for load. 2Updated load rating—Completion of load rating computation with a finding to post for load. 3Bridge database—Data entry of new load rating values to bridge inventory file. 4Notification to owner—State’s formal notice to a bridge owner that posting for load is required at a bridge. 5Posting implementation—Placement and verification of weight limit signs at bridges. to TABLE 37 POLICIES ON TIME INTERVALS FOR LOAD RATING AND LOAD POSTING

20 WEIGHT LIMIT SIGNS The U.S.DOT Manual of Uniform Traffic Control Devices includes five standard signs for weight restrictions on high- way structures (47) (Figure 1): R12-1 GVW limit, R12-2 axle weight limit, R12-3 empty GVW limit, R12-4 axle load limit plus GVW limit, and R12-5 limits on GVW of single vehicles, tractor-semi-trailer combination vehicles, and truck-trailer combination vehicles (the silhouette sign). Thirty-four survey states use the U.S.DOT R12-1 weight restriction sign and 27 the R12-5 silhouette sign. Several states use both. Fewer states use the U.S.DOT R12-2, R12-3, and R12-4 signs (Table 38). Survey responses on states’ use of weight limit signs are listed in Table A10. Notes on States’ Signs for Weight Limits Some states have signs that are modifications of U.S.DOT signs, as well as signs that are state-specific designs. The Illinois R12-I100 sign shows limits on GVW for single-unit vehicles, and for 4-axle and 5-axle combination vehicles (Figure 2). The Illinois’ R12-I105 sign restricts bridge cross- ings to one truck at a time. Missouri uses signs to restrict truck speed and travel lane in addition to GVW. New Hampshire’s E-1 and E-2 excluded crossing signs prohibit crossing by some single-unit (E-1) and combination (E-2) vehicles. New Hampshire’s caution cross- ing signs limit bridges to use by one truck at a time for single- unit vehicles (C-1), both single-unit and combination vehicles (C-2), and by combination vehicles only (C-3). Single-unit trucks are excluded from bridges restricted as C-3 crossings. report, which is reviewed by Arizona DOT’s QA manager before final acceptance. Arizona uses Virtis (40) for most load rating analyses, and conducts independent checks using other rating or analysis software such as GT-Strudl (41), MDX (42), Simon, Conbox (43), or Conspan (44). Arizona uses reports from safety inspections in QC for load ratings. The load rater and load rating reviewer must each use the most recent inspection report. Florida applies peer review to all load rating computa- tions (18). Load raters are encouraged to perform hand calcu- lations to verify results of computer programs for load rating. Florida conducts annual QA reviews of the load rating per- formance of DOT districts. Florida DOT districts implement QC plans that ensure that decisions to re-evaluate load ratings are addressed at every safety inspection. Districts have QC plans to manage load ratings by engineering consultants. QC plans set limits on the times for completion of load rating computations and for updates to Florida’s bridge database. Florida’s bridge database yields a Comprehensive Inventory Data Report that is used to approve and to route overweight permit loads. Indiana applies peer review to load rating computations, and makes QA reviews of load ratings of samples of structures (19). Iowa makes peer review by PEs of all load ratings, and keeps records of peer review using a Load Rating Evaluation Form (45). New Mexico’s QC procedure employs two load rat- ers working independently (46). The outcomes for load ratings are compared. Load ratings are accepted if the independent evaluations are within 2% of each other. Failing that, details of rating computations and structural models are examined and differences are identified and resolved. The process continues until agreement within 2% is achieved. New Mexico checks samples of load ratings by engineering consultants. Consul- tants are notified of all errors, and must correct known errors and examine their procedures in the context of such errors. Utah applies peer review of load rating computations and documents the review as part of the bridge file (34). Virginia uses peer review for QC of load ratings (25). QA in Virginia is the verification that QC has been performed. Virginia under- takes QA review of all load ratings submitted by local govern- ment bridge owners. The state survey responses on quality practices in load posting are listed in Table A9. FIGURE 1 U.S.DOT weight limit signs (47 ). U.S.DOT Standard Sign States Using U.S.DOT Sign Count R12-1 34 R12-2 8 R12-3 0 R12-4 1 R12-5 27 TABLE 38 SUMMARY—USE OF U.S.DOT SIGNS FOR WEIGHT LIMITS

21 Installation of Weight Limit Signs In 24 survey states, central office staff of the DOT direct installation of weight limit signs at structures posted for load (Table 39). In 19 states, DOT staff in districts direct instal- lation of signs. The presence and adequacy of weight limit signs are verified by bridge safety inspectors in 41 survey states (Table 40). Seven states use maintenance crews to ver- ify weight limits signs. In five states, both safety inspections and maintenance crews verify weight limit signs. Survey responses on installation and verification of weight limit signs are listed in Tables A15 and A16. Eight survey states post weight limit signs at weight- restricted bridges (Table 41). Weight-restricted bridges are open to legal loads, but not open to overweight permit loads. Oregon’s sign for weight-restricted bridges states that loads are limited to legal loads. New York’s sign notes the exclu- sion of trucks operating with overweight permits. Survey responses on the use of weight limit signs at weight-restricted bridges are listed in Table A17. FINES FOR VIOLATION OF WEIGHT LIMITS Fines for violations of weight limits range from $0.01 per pound to $0.75 per pound of excess weight. The median fine is $0.20 per pound. Many states impose increasing fines per pound for larger overweight violations. Some states have separate schedules for violations of limits on axle weights Nebraska’s R12-5a and R12-5b signs show limits specifi- cally for loads on interstate highways (Figure 3). Nebraska’s signs show limits for loads on single axles and tandem axles together with limits on GVW. Ohio’s R12-5 sign shows truck silhouettes, load limits for each, and the distance in miles from the sign to the restricted bridge (50). Oregon’s R12-4 signs shows limits for axle weights, tandem-axle weights, and GVW (Figure 4). Texas’ R12-2cT and R12-4aT signs include load lim- its for tandem axles (Figure 5). Texas’ R12-6aT, R12-7aT, R12-6bT, and R12-7bT signs show limits for load-zoned routes and advise truckers of available detours. Texas’ R12-8aT signs show limits on load for single axles, tandem axles, single-unit vehicles, and combination vehicles. Washing- ton uses a modified version of the U.S.DOT R12-5 sign. Wisconsin’s standard weight restriction sign shows a limit on GVW only. FIGURE 2 Illinois weight limit signs (48). FIGURE 3 Nebraska weight limit signs (49). FIGURE 4 Oregon weight limit sign (51).

22 Staff Verifying Weight Limit Signs States Count Safety Inspectors Only 36 Maintenance Crews Only 2 Both Safety Inspectors and Maintenance Crews 5 TABLE 40 SUMMARY—VERIFICATION OF WEIGHT LIMIT SIGNS Weight Limit Signs at Restricted Bridges States Count Yes 8 No 35 TABLE 41 SUMMARY—WEIGHT LIMIT SIGNS FOR PERMIT LOADS and for violation of limits on gross weights. Some states have separate schedules for specific commodities or for repeat offenses. Table 42 summarizes overweight fines among U.S. states. A detailed listing of fines for overweight violations can be found in Table B1. Schedules for overweight fines run from 1,000 lb to as much as 50,000 lb. Schedules that run to 5,000 or to 10,000 lb are more common. Maine and New York have schedules of fines that express overweight violations as percentages of permissible weight. STATE ROLE IN LOAD POSTING OF LOCAL GOVERNMENT STRUCTURES Authority to Post Local Structures Twenty-three survey states reported that authority to load post structures that are owned by local governments is shared between local governments and the state governments (Table 43). Twenty states reported that local governments alone hold load posting authority on local roads. States have responsibility under federal regulation to report load ratings and load postings for bridges and culverts on public roads within their boundaries, excluding structures owned by the federal government (35). In consequence, state DOTs are informed on the conditions, load ratings, and load FIGURE 5 Texas weight limit signs (52). Note: “Load zoned” indicates limits on axle weight and GVW for some routes, usually county roads, to preserve pavements and structures that were designed for loads less than state legal loads. DOT Staff Responsible for Installation of Weight Limit Signs States Count Central Office 24 District Office 19 TABLE 39 SUMMARY—INSTALLATION OF WEIGHT LIMIT SIGNS

23 TABLE 42 RANGE OF OVERWEIGHT FINES State Overweight Range, lb Overweight Fine, $/lb Note Arizona (53) 1,000–5,000 0.10–0.29 Colorado (54) 1,000–10,000 0.038–0.294 Fine + surcharge Delaware (55) to 5,000 0.023–0.0575 First offense over 5,000 0.0575–0.115 Second offense Florida (56) — 0.05 Georgia (57) — 0.05 0.0625 Overweight permit Idaho (58) 1,000–20,000 0.005–0.03 Illinois (9) 1,000–5,000 0.05–0.30 1,000–3,000 0.02–0.20 Axle, overweight permit Indiana (59) 1,000–5,000 0.02–0.10 Typical, not mandated Iowa (60) 1,000–20,000 0.012–0.10 Axle, tandem axle, axle group Kansas (61) 1,000–7,500 0.04–0.10 GVW Louisiana (62) 1,000–11,000 0.01–0.11 GVW Maine (63) 1% to 40% 0.02–0.175 GVW, six axle combinations 1% to 50% 0.0125–0.225 Axle, axle group, GVW Maryland (64) 1,000–20,000 0.01–0.40 GVW Massachusetts (65) to 10,000 0.03 Massachusetts Turnpike over 10,000 0.06 Michigan (66) 2,500–5,000 0.04–0.10 GVW Minnesota (67) 1,000–7,000 0.01–0.20 GVW Montana (68) 2,000–25,000 0.015–0.08 Axle, axle group Nevada (69) 1,500–10,000 0.01–0.08 New York (70) 2% to 40% GVW North Carolina (71) 1,000–5,000 0.06–0.10 Axle or tandem axle 2,000–5,000 0.02–0.10 Axle group North Dakota (72) 1,000–30,000 0.02–0.20 Ohio (73) 2,000–10,000 0.04–0.16 Oregon (74) 1,000–12,500 0.10–0.24 Schedule I 100–10,000 0.10–0.30 Schedule II–Overweight permit 5,000–10,000 0.20 Schedule III–Posted weight limit >10,000 lb is Class C misdemeanor (continued on next page)

24 Notes on State Government Role in Load Posting for Locally Owned Bridges Florida advises local owners of the need to post structures for load. If the owner does not respond within 30 days, the state of Florida will post structures for load (18). Georgia DOT under- takes safety inspections of all structures on public roads that are owned by state or local government. Georgia DOT does not inspect structures on privately owned roads (82). Georgia DOT advises local governments of the need to post structures for load, and provides local governments with findings of inspections and recommendations for maintenance. Indiana requires local governments to perform load ratings, and QC of load ratings, and to post for load, if necessary. Local government owners must re-rate their structures when modi- fication or deterioration requires (19). Louisiana requires that local governments set and enforce weight limits at their struc- tures. The Louisiana State Maintenance Engineer audits per- formance of local governments in load rating and posting (20). Maine DOT inspects all structures on public roads, and main- tains most structures in the state, including many structures on town ways. Towns maintain low-use bridges and redundant bridges (83). Maine DOT advises towns of the need to post town-maintained structures, when necessary. Michigan allows local governments to post their structures for loads that are less than loads indicated by rating analysis. Michigan notes that lower postings can extend the service life of bridges (84). Minnesota places responsibility for load rating with local government bridge owners, and requires postings of locally owned structures. In many states, DOTs are involved in safety inspection programs for locally owned structures. Some states perform load rating computations for locally owned structures, which are shared with local governments. When actions such as load posting are needed, state governments advise and, if necessary, act in place of local governments. Overall, there is a practice of deference by state govern- ment to local government bridge owners and, if response by local government is lacking, action by state government to post structures for load, to issue overweight permits, and generally to promote mobility and ensure safety on public roads in the state. Comments of survey states on the state role in lost posting of local government structures are listed in Table A19. State Overweight Range, lb Overweight Fine, $/lb Note South Dakota (75) 1,000–10,000 0.05–0.75 Texas (76) 5,000–10,000 0.03–0.10 Axle, tandem axle or GVW 0.06–0.20 Second conviction in 12 months Utah (77) 2,000–25,000 0.04–0.13 Axle 0.02 GVW Virginia (78) 2,000–12,000 0.01–0.35 Axle 0.01–0.20 GVW 4,000–12,000 0.01–0.30 Axle, forest or farm products 0.05–0.15 GVW, forest or farm products Washington (79) 4,000–20,000 0.03–0.30 West Virginia (80) 1–50,000 0.006–0.04 Wisconsin (81) 2,000–5,000 0.01–0.07 First conviction 0.02–0.10 Second conviction in 12 months 0.08–0.11 Raw forest products 3,000–5,000 0.20–0.23 Third conviction in 12 months. Raw forest products TABLE 42 (continued) State DOT Posts Local Government Structures States Count State Computes All Load Ratings 3 By Route System 6 Local Government Delegates to State 3 Case-by-Case 11 No State Role 20 TABLE 43 SUMMARY—STATE ROLE IN LOAD POSTING OF LOCAL GOVERNMENT STRUCTURES

25 local government submits updated load rating calculations to the State Bridge Operations Engineer, and (3) the State Bridge Operations Engineer approves the change. Virginia DOT maintains all interstate and primary routes in Virginia, as well as secondary roads in 90 of 92 counties (85). Legal Loads for Local Government Structures Thirty-one survey states reported that local governments can set limits for legal loads on their structures that are less than legal loads cited in state law. In five states, other coordina- tion of legal loads exists between state and local govern- ments (Table 44). States establish corridors for truck routes and allow trucks to travel short distances, often one mile or less, to access services on local roads. Local governments must allow trucks to use local roads to reach final points of the delivery of goods. States enjoin local governments from establishing load limits affecting roads that serve warehous- ing or manufacturing facilities, especially for facilities that are adjacent to truck routes (see Table A18). Iowa DOT issues system-wide overweight permits that allow loads to travel on roads under state or local govern- ment jurisdiction (86). immediate posting for load, when needed, unless bridge own- ers undertake expedited repairs (37). Montana DOT inspects local government structures. Inspectors coordinate their visits with local bridge owners, so that local owners can participate. Montana notifies local bridge owners of problems found dur- ing inspection (21). Ohio DOT inspects and evaluates structures having spans of 10 to 20 ft using the same methods required under U.S. national bridge inspection standards (NBIS) for structures with spans greater than 20 ft (23). Ohio law extends the require- ment for inspection of short spans to local government bridge owners. State requirements for quality practices extend to load rating by local governments. In Texas, counties can assign load limits to their structures only with the consent of the state DOT (39). The state DOT advises local governments of necessary postings for load and furnishes the weight limit signs. In Utah, the State Bridge Operations Engineer advises local governments of necessary posting for load (34). Local governments must implement postings within 180 days. Post- ing for load may be rescinded if (1) repairs are made, (2) the State Local Post Lower? State Local Post Lower? Alabama Yes Missouri Yes Alaska No Montana Yes Arizona Yes Nebraska Yes California Yes Nevada Other Colorado Yes New Hampshire Yes Delaware Other New Mexico Yes Florida Other New York Yes Georgia North Carolina No Hawaii Yes North Dakota Yes Idaho Ohio Yes Illinois Yes Oklahoma Yes Indiana No Oregon Yes Iowa No South Dakota Yes Kansas Yes Tennessee Yes Kentucky Yes Texas Other Louisiana Yes Utah Other Maine Virginia Yes Maryland Yes Washington Yes Massachusetts Yes West Virginia Yes Michigan Yes Wisconsin Yes Minnesota Yes Wyoming Yes Mississippi Yes TABLE 44 LOAD LEVELS SET BY LOCAL GOVERNMENTS FOR THEIR STRUCTURES

26 intervals for updating load ratings in bridge databases, for coordination among DOT branches in the course of load rat- ing and posting, for response by local governments to states’ advice to post for load, and for verification of weight limit signs at structures. QC and QA practices for safety inspections and for load rating support the quality needs in load posting. States use reviews of safety inspections, peer review of load rating models and computations, and field verification of weight limit signs to ensure that load postings are properly evaluated and implemented. Thirty-four survey states use the U.S.DOT standard R12-1 sign to post GVW limits at load posted structures. Twenty- seven survey states use the U.S.DOT standard R12-5 sign to post GVW limits at posted structures for single-unit vehicles, tractor plus semi-trailer combination vehicles, and truck-trailer combination vehicles. States also use state-specific signs for weight limits. Eight survey states post weight limit signs to exclude overweight permit vehicles at structures that have adequate strength for legal loads. Fines for violations of weight limits range from $0.01 per pound to $0.75 per pound of excess weight. The median fine is $0.20 per pound. Many states impose increasing fines per pound for larger overweight violations. SUMMARY State DOTs can post state-owned bridges and culverts for load. In 36 survey states, load posting decisions are made in the DOT central office. In most states, local governments have the authority to post the structures owned by local gov- ernments. In all states, state governments have the respon- sibility to ensure that all structures, state-owned and local government owned, are inspected, evaluated, and posted in conformance with federal regulation. Among survey states, Georgia, Maine, Maryland, Mon- tana, and Virginia inspect all or most bridges and culverts owned by local governments, and advise local governments on maintenance and load posting. Twenty-three survey states reported some extent of authority or participation by state DOTs in load posting of local government structures. Thirty-four survey states perform all or most load rating evaluations using DOT staff. In 28 states, load ratings are re- evaluated on the recommendation of safety inspectors. Sixteen survey states re-evaluate load ratings when low GCRs are reported. Time intervals for tasks in load posting vary. Actions are taken immediately to ensure the safety of structures. Federal regulation, state statutes, and DOT policies set limits on time

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TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 453: State Bridge Load Posting Processes and Practices is a synthesis of the practices of U.S. state governments in restricting weights of vehicles that can cross highway bridges and culverts to levels below legal loads. Bridges and culverts restricted for vehicle weights are called load posted structures. The load posting practices of bridge owners include the identification of structures to post for load, the evaluation of safe load capacities of these structures, and the implementation of restrictions on vehicle weights at structures.

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