From City Limits:
Every time a new mayor or borough president gets elected, the city pays around $350 to update each of the affected signs. Those corrections and the entire set up, removal, and replacement of almost all the city-owned sign inventory are orchestrated at a city-owned facility, a sign factory if you will, located in Maspeth Queens.
In a red-brick building resembling a garage or repair shop, employees here either paint or laminate colors onto aluminum. Then, they stencil or paint on letters by hand. With around 25 employees, the sign shop in Queens is reportedly the largest of its kind in the nation.
Each year, the NYCDOT’s Borough Engineering Sign Shop in Maspeth has to replace or create 100,000 new signs. The entire city sign operation -- which includes the studying of locations, their fabrication and installation -- costs around $12 million annually.
Faded or damaged signs that get returned or retired to the factory in Maspeth are first inspected for possible refurbishment. When the signs are in good enough condition to be refurbished, they are reused. Signs that can’t be refurbished are delivered to a metal recycling yard, which in turn sends the scrapped aluminum signs and metal sign supports off to a recycling plant.