3dis that Aren't--State Route Spurs and Loops

I-378 Shield

3di's that Aren't

There are thousands and thousands of miles of interstates, with 116 or so 3 digit interstates (3dis) to boot. They range from I-476 in Pennsylvania, 131 miles long, to the short twin spurs I-175 and 375, serving downtown St. Petersburg, Florida. Those 3dis are the backbone of urban Interstate expressways and freeways (well, I said both to help the New Yorkers and the Angelenos...)

Occasionally, however, some 3dis are Pennsylvania standard, violates Interstate rules, the mainline is routed away from the 3di, or the 3di just doesn't cut it. Because of this, we have what I call 3di's that Aren't. Those are state routes that are 3dis of another interstate or were once of another interstate.

Now, this page is here to list every state route 3di in the United States. No, secret 3dis like I-595 and I-H201 don't count, they are legitimate Interstate 3dis. And no, former AZ 360 isn't one, that is a state route 3 digit of US 60. I'm talking about things like the orphaned PA 378, the Pennsylvania-standard DC/MD 295, the interstate-violating VA 195...I could go on and on, but let's start with the list. However, for space considerations, I am not going to do the NY 3di extensions...

PA 283: Harrisburg, Pennsylvania to Lancaster, Pennsylvania

PA 378: Bethlehem, Pennsylvania

PA 581: Harrisburg, Pennsylvania

IL 190, 194, 594: Chicago Area, Illinois

IL 394: South Holland, Illinois to Ford Heights, Illinois

VA 195: Richmond, Virginia

DC/MD 295: Baltimore, Maryland to Washington, District of Columbia

CA 110: Pasadena, California to Los Angeles, California

CA 480: San Francisco, California

CA 905: San Ysidro, California to Otay Mesa, California

NJ 495: New York State Line (Hudson River, on the Lincoln Tunnel) to Secaucus, NJ

NY 878: Queens, New York City, New York