During the same visit I found a number of photographs that depict the original Unimark signs in use in the early 1970s. They provide a clearer understanding of the slow spread of the new signs through the subway system. The photographs were taken by the TA to document changes to stations. Thus it can be assumed that the dates are very close to the dates when the signs were installed.
Photographs showing the black on white signs:
4 April 1968 Lexington Avenue & 59th Street (BMT)
26 June 1968 57th Street (6th Avenue, IND)—at the inauguration of the station
3 January 1969 Jay Street (IND)
April 1969 West 4th Street (IND)
26 June 1969 Lawrence Street (BMT)
Note these signs preceded Unimark’s completion of the NYCTA signage manual in 1970.
29 October 1971 Prospect Park (IND)
30 May 1973 42nd Street (6th Avenue, IND)—these photographs appeared in “Il campo della graﬁca italiana” Rassegna 6 (1981).
2 May 1975 Canal Street (BMT)
22 October 1975 Atlantic Avenue (IRT, BMT)
27 August 1976 49th Street (BMT), Stillwell Avenue (Coney Island, IND & BMT), Brooklyn Bridge (City Hall, IRT)
It is clear from these and other photographs that the first stations to receive the new signs were along the Broadway BMT (R), 4th Avenue BMT (R) and IND (F) lines. These lines were part of the upheaval occasioned by the completion of the Chrystie Connection in 1967. (I am using contemporary line designations here not those in use during these years.)
Photographs showing early examples of the white on black signs:
21 February 1975 Lexington Avenue & 59th Street (BMT)
18 March 1975 Times Square (IRT), 72nd Street (IRT) and 96th Street (Broadway IRT)
March 1977 49th Street (BMT)
Unfortunately the photographs taken by the NYCTA Photographic Unit are sparse before 1968 and peter out after 1977. Thus, we have none documenting the early work of Noorda and Vignelli in 1966 nor do we have any showing what happened after the introduction of the Hertz/Tauranac map in 1979.