Funks Grove Rest Area Bridge

Actually I believe they are newer than the 1975 date listed. These bridges were originally only a single span that carried I-55 across the county road, when the rest area was built in the mid 80's these bridges were extended and appear to have been completely replaced. These spans even have a different guardrail than the others on this section of I-55, these 2 spans have solid concrete NJ type barrier guardrails, all of the others have the slightly lower concrete with a single metal tube on top. I never crossed under it prior to the its lengthening and the opening of the rest area but I would guess it was a standard single span beam/girder like the rest of the bridges on this stretch of I-55

This bridge one of the few interesting things visible on I-55 between Chicago and St. Louis. It caught my eye driving over it, surprised to see a 1975 date, I was guessing 1960s. I wonder why the usual design was used in the 1970s.