I recall seeing a sign on a low tunnel in NY (?) that had something like "15 feet We mean it!" edit: I'm not from NY I Googled and see it is the Holland tunnel

I recall seeing a sign on a low tunnel in NY (?) that had something like "15 feet We mean it!" edit: I'm not from NY I Googled and see it is the Holland tunnel which has the sign 12'6" (but it's actually 13') and We mean it.