Oakgrove Road Township Bridge is an example of a bridge IDOT considers both “Functionally Obsolete” and “Structurally Deficient.” Photo by Adela Crandell Durkee

In 2012, IDOT spokesperson Ann Schneider proclaimed one in twelve Illinois bridges deficient (8 percent,) compared to the national average of one in nine (10 percent.) IDOT set about to rectify the problem by repairing or replacing over 1100 bridges.

The most recent IDOT inspection for McHenry County’s 226 bridges classified 46 of them as “Functionally Obsolete” or “Structurally Deficient.” IDOT deemed another 13 both “Functionally Obsolete” and “Structurally Deficient.” In other words, IDOT classified 26 percent of McHenry County Bridges deficient; over three times the number considered unacceptable for Illinois.

Some McHenry County bridges were constructed over a century ago. The Edwards Road Bridge over the Fox River Inlet was built in 1900. At least one bridge considered deficient was built or reconstructed as recently as 2013. Eight of the 13 bridges deemed both “Functionally Obsolete” and “Structurally Deficient” appear on the 2013-2017 schedule for replacement or rehabilitation. The schedule indicates replacement of the Edwards Road Bridge in 2016. In the meantime, the bridge remains closed. Other deficient bridges remain closed to traffic, but not all.

Oakgrove Road Township Bridge is an example of a bridge IDOT considers both “Functionally Obsolete” and “Structurally Deficient,” with a sufficiency rating of 19.3 out of a possible 100. IDOT’s assessment includes:

• Advanced deterioration of deck;
• Advanced deterioration of superstructure;
• Structural Evaluation: Intolerable, high priority for correction;
• Deck geometry minimum adequacy;
• Bridge Railing doesn’t meet standards;
• Approach guardrail unacceptable.

The Oakgrove Township Road was built in 1935. Construction to replace the bridge is part of the 2017 plan. In the meantime, the bridge remains posted with a load limit of 14 tons.

Federal Funding for replacement is available if the sufficiency rating is under 50, and for rehabilitation if under 75. Federal funding requires a minimum 20percent local match. Township bridge work is eligible for state township bridge program (TBP) funds. The County funds the local share of engineering and construction work for bridges with the County Bridge fund. The program for 2013 through 2017 replaces or rehabilitates many of the bridges that are closed or unsafe, and includes culverts under various county roads. The cost is over $24 million and leaves out four of the most dilapidated bridges, along with 46 other bridges IDOT classifies as “Functionally Obsolete” or “Structurally Deficient.”