Posting for a bridge in Cooper Township, Sangamon County.

Repair and replacement of local bridges is a familiar, continuing and monumental task for many of you. Today, I want to again discuss the problem of load posting for those bridges that are approaching the end of their useful life to the extent that they cannot safely carry loads that are otherwise legal.

In 1968, Congress established the National Bridge Inspection Standards (NBIS). Initially, the NBIS emphasized only bridges on the several federal-aid systems — primary, secondary, urban and interstate. However, with the cooperation of all highway agencies, Illinois acted early-on to include off system bridges as well. The 1978 Federal Highway Act extended the NBIS to all bridges open to public travel. This program requires all bridges spanning 20 feet or more and open to public travel to be inspected at least every two years and rated to determine their load carrying capacity. Bridges found to be structurally deficient through this process are assigned load limits and are to be posted with weight restrictions by the responsible highway agency until such time as they can be repaired or replaced.

Weight limit signs located sufficiently ahead of both bridge ends to allow the driver time to react are required. Guidelines for the signs are contained in the Illinois Manual on Uniform Traffic Control Devices for Streets and Highways (Illinois MUTCD). Signs also may be placed at intersections nearest the bridge. Any bridges not capable of carrying at least 3 tons are to be closed to traffic rather than posted with weight restrictions.

Based on current inventory, the Illinois Division of Highways has 86 structures on roads maintained by or for the State which require load postings. This is a meaningful although encouragingly low number (of 7584 bridges) and speaks well of the continuing emphasis which the Department has been able to place on bridges.

Our best interpretation of information available from the "Structure Data Bank" leads us to the conclusion that as many as 4500 bridges on municipal streets, county highways, and road district roads require posting. Only 2900 bridges are currently encoded as posted in the Data Bank. These are damaging statistics; however, it helps a little it we recognize that there are in excess of 17,000 structures spread across most of the 2800 local highway authorities in Illinois.

On July 18, a letter was sent to each of the nearly 1500 Road District Highway Commissioners in an effort to gain their support in addressing the problem. Similar letters are being addressed to the individual municipal governments that have structures that either have been or should be posted.

To add to the urgency of this problem, Congressional inquiry is presently underway to determine which governmental agencies are not in compliance with the NBIS. Inadequacies in the required frequency of inspections and proper load postings may directly jeopardize the safety of the traveling public and are now being closely monitored for corrective action.

On a national basis, there are some local governments and a few states that apparently are not earnestly pursuing NBIS compliance on all public roads. A spirit of cooperation between this Department and local governments has tor the most part brought about a very effective bridge inspection program in Illinois to the extent that the public is provided assurance that bridges

September 1985 / Illinois Municipal Review / Page 17

are safe to use. The only exception that we can identify is what appears to be a reluctance on the part of some agencies to properly post any restricted load limits.

It is quite clear that the Federal Highway Administration (FHWA) has the authority and the responsibility to introduce sanctions in the event a State or local agency fails to satisfy the intent of the NBIS. Said more clearly, FHWA approval of Federal-aid funds within a State or local jurisdiction is conditioned on compliance by the State or local jurisdiction with the NBIS.

We know that in at least one state, all federal-aid for highways to all local jurisdiction is now conditioned on a current certification that all structures are in full compliance with the NBIS (including posting). There is also a known situation in a Texas county where the County failed to post a structure upon proper notification. The structure was subsequently failed by a truck of legal load, the truck and driver were harmed, and the trucking firm has sued the County to recover.

In Illinois, there have been programs for the replacement of bridges for several years. The annual $15 million Township Bridge Program has provided 2370 structures starting in fiscal year 1977 through June 30 of this year. With the Federal BRRP funds, local agencies have built (or rebuilt) about 1070 bridges commencing in fiscal 1978 through June 30. Many additional structures have been constructed utilizing FAS, Urban, and Interstate Transfer funds. Federal-aid funds are often utilized in combination with Township Bridge Program funds and other local revenues. Thus sanctions, however justified or well intentioned, could have serious impact.

Aside from the fact that the unwary motorist deserves to know when they are about to traverse an unsafe structure or one having restrictions, we believe the liability which the owner jurisdiction places upon itself when it fails to properly post its bridges in accordance with the Illinois MUTCD and to adequately maintain such signing far outweighs any supposed benefit which could possibly result from ignoring the intent of the law.

Hopefully with the added emphasis given by our letters to the Highway Commissioners and municipalities and the increased awareness generally, we will be able to lay quietly to rest the matter of bridge posting. It there arc still non-believers in the NBIS out there, please call your District Local Roads and Streets Engineer or me personally at (217) 782-3970.

Credits to:
Lloyd E. Dixon
Local Project Implementation Engr.

Page 18 / Illinois Municipal Review / September 1985