Although not shielded, NYSDOT reference markers identify the route as “878I” for the freeway portion within the vicinity of Interstate 678 and John F. Kennedy Expressway. The I suffixed on NYSDOT reference markers identifies an Interstate highway. According to Steve Anderson’s site, I-878 shields were posted in 1989 when the Interstate designation was first confirmed.
Prior to the renumbering of I-278 and I-895 in Bronx, New York by AASHTO on June 23, 1969:, the Interstate 878 designation was reserved for the Bruckner Expressway east from the Sheridan Expressway (I-895) to the Bruckner Interchange with I-95. During that time period, Interstate 278 followed the Sheridan Expressway north to the Cross Bronx Expressway. It was proposed to extend 5.2 miles further along an alignment over U.S. 1 (Boston Post Road) northeast to Interstate 95 at the New England Thruway. The Sheridan Expressway extension however was dropped in 1971, along with several other metropolitan expressway proposals.2 I-278 was instead realigned over planned I-878 and the short section of the Sheridan Expressway was redesignated as Interstate 895. For more, visit Steve Anderson’s Sheridan Expressway.