When it comes to the New York City subway, what once was old is new again.

The Metropolitan Transportation Authority on Wednesday revealed a revamped map of the city’s subway system that takes its cues from a 1970s throwback that was cheered by design connoisseurs and reviled by many traditionalists.

It is the first major overhaul of the subway map to be introduced by the authority in almost 50 years.

The reveal of the map, on a train platform in Times Square, was another step in the M.T.A.’s campaign to revitalize the subway’s image. The move comes at a time when the authority is lobbying for billions of dollars to upgrade the city’s mass transit system, while fending off criticisms from Washington about crime and congestion pricing.

The new map — a brightly colored variation on the current version that sacrifices some geographic detail for clarity — is reminiscent of the 1972 Unimark map, a modernist streamlining of the subways that straightened the curvy contours of the system. The map was short lived, replaced in 1979 by a version resembling the current one.

Critics of the Unimark map bemoaned its stark departure from conventional maps. Landmarks seemed squished together. Bodies of water were beige. Tourists who misjudged the distance between stops were confounded. But fans saw an elegant solution to an increasingly complicated system.

The updated version, which blends elements of the Unimark design with a successor known as the Tauranac map — named after John Tauranac, a well-regarded New York mapmaker — is already being displayed on digital monitors, and will be posted in subway cars and platforms over the next several weeks, the M.T.A. said.