View from the Grand Central Parkway (GCP to it's friends and little directional signs) from the Parsons Boulevard overpass, looking eastward toward 164th Street. The right-side lanes of the Grand Central here had to be crammed under the cantilevered service roads during its widening in the mid 1960s, from 4 to 6 lanes.
The elliptical lighting mast arms from that widening, that I lovingly nicknamed "crook arms", have all survived. Their original luminaires, however, and probably another subsequent generation of replacements, have not.
The original mercury vapor fixtures were General Electric model 400, that I nicknamed the Disgusteds, because of the scowl their diffuser bowls seem to give off depending on how light hits them during the day. At the point I wrote this in 1997, the prevalent light fixtures, dating from the early 1980s, were miniature versions of the scowling originals.

UPDATE from November 1999: Nothing much changed that you'd notice from here, but some kind of funky construction was taking place under the eaves. Weird and supremely hideous girder brackets were installed under the cantilever ceiling of the eastbound lanes. They had been working on the lighting under there, maybe putting in drop-ceilings! Perhaps they intended to give this whole stretch of un-park-like parkway a receding rain cover, like some stadiums have. Maybe they were getting ready to double deck, or cover over the roadway and put a real Grand Central Park in the middle between the service roads! Yeah, right, like we'll ever see that happen.