Loose Highmast

Those group of highmasts dates to the late 70s. Approx 1977-1979. Those are in the late 1970s part of the highway I-95 just near the Baltimore City. (I am not sure what this particular one dates as some of them as similar style but with FCO lens instead of refractored style lens.

You will understand why you see some groups of different highmasts if you read history of how Maryland I-95 was built....see Construction at http://en.wikipedia.org/wiki/Interstate_95_in_Baltimore,_Maryland#Construction