Robert Caro, author of The Power Broker: Robert Moses and the Fall of New York, once referred to the Triborough Bridge (known officially as the Robert F. Kennedy Bridge) as “a traffic machine.” This nickname could not be more suited to the superstructure. Regarded as one of the most significant achievements of the Public Works Administration, R.F.K. Bridge is comprised of a complex of three bridges that connect the Bronx, Manhattan, and Queens. Thousands of commuters speed over its roadways every day. Yet, despite its renown, it still holds many secrets.

10. A Sign Once Advised Travelers to Drive off the Bridge

According to New York Times columnist, William Safire, the R.F.K. Bridge once held a sign, which advised travelers to drive off the bridge in the event of an attack. Since its roadway is located roughly 15 stories above the river, the drop would have certainly resulted in death. In the column, Safire also mentions the wry type of signage that used to pepper New York City streets, like “Don’t even think of parking here” and “No Parking/No Standing/No Stopping/No Kidding.” Things have become much more serious since then.