As New Yorkers, we’ve often been told that we don’t look up enough — but if we don’t also look down, we might miss out on a subtle signaling system built into the city’s streets! Peer closely enough and you’ll soon notice dozens of small, colorful milk-carton-like caps embedded in Big Apple pavement — but what are they, and what do they mean?
Wonder no more — thanks to a tip-off from New Yorker Norberto Briceño’s “Kinda Interesting Things” series, we learned that the mysterious, tiny sidewalk circles are Department of Transportation-ordered asphalt tags — most commonly referred to as “A-Tags”. The miniscule markers, created by longtime Minnesota-based manufacturer Rhino Markers in 1987 were installed by the DOT in 2006 as a way to more easily identify the ownership of permitted construction work. Labeled by the year of the project as well as the contractor/utility agency, the markers make quicker work of figuring out when to call ConEd or the Fire Department in the event of needed repairs.
Agencies and categories of work are organized by color as well as a five-digit code to identify individual contractors:
- Cherry red: Verizon
- Yellow: Empire City Subway, Buckeye Pipe Line, Long Island Power Authority
- Light Blue: ConEd
- White: Keyspan
- Green: plumbers
- Orange: signals and street lights
- Purple: Metropolitan Transit Authority, Fire Department
- Regal Blue: Cable TV providers

“You know that little plastic thing that holds up the center of a pizza box? It’s basically a glorified version of that,” Rhino executive Tom Preston told Medium writer Paul Lukas in a 2014 article on the program. “But it’s been a really good success story — we solved a problem for New York City.”
While color-coded painted construction markers have long been a standard in DOT regulations, the advent of A-Tags has significantly helped residents and city officials find the right agency in charge to address street-level issues, then-DOT Director of Operations Joseph Yacca added to Medium. “Before the A-Tags, we used painted marks, but the painted marks were just color-coded — they didn’t identify the individual user,” said Yacca, adding that the implementation of A-Tags has not only made it easier to know who to call before building on top of a gas or electrical line but also to more accurately issue violations. “For example, every plumber was green, so if you found a green marker, you knew you were looking for a plumber, but you didn’t know who. So we used to have to pull all the old permits and so on. Now we can pinpoint it much faster.”
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The simple, multi-prong marker design has been so successful that it has since been implemented in Boston and Pittsburgh, but you don’t have to travel far to find them — there are plenty of A-Tags in Hell’s Kitchen. We managed to find red, yellow, light blue, green and orange examples.
So the next time you’re curious to find out what’s below New York city streets (other than that mythical sewer alligator), be sure to keep an eye out for the humble A-Tag!
Reminded me of Toyenbee tiles. We’ve got a few of those in the neighborhood too