Most common street name in the U.S.?

Someone told me that the #1 most common street name in America is actually “Second Street.” And he added that “First Street” ranks as the sixth most common street name in America.

That sounded pretty hard for me to believe, but I just did a search with Ask.com and it appears to be true.

http://www.ask.com/web?q=what+is+the+most+common+street+name+in+america?&search=&qsrc=364&o=0&l=dir

Though for all the sites that state this information, none explain why. And I can’t even begin to come up with an explanation myself.

Can anyone come up with any guess for an explanation?

I have several suggestions: what would be First Street is called Main St; what would be First St is a named highway e.g. Sunrise Hey; First St is the first thoroughfare to be renamed to honor a local politician, e.g. Washington Ave.