NY 878 is maintained in part by the New York City Department of Transportation (NYCDOT); the New York State Department of Transportation (NYSDOT); and the government of Nassau County. The NYSDOT also maintains part of Rockaway Boulevard, which is designated as the reference route NY 909G. The of NY 878 between I-678 and the JFK Expressway is officially designated Interstate 878 (I-878), but not signed as such. This segment is instead signed as NY 878. The NYSDOT designated the eastbound lanes of the freeway as I-878 in January 1970, but the entire Nassau Expressway was publicly re-designated as NY 878 by 1991. The unsigned Interstate 878 is the shortest Interstate Highway in the United States.