Shaping the City: Let there be light (carefully) in Metro stations
Lately Metro has taken a lot of heat because of persistent subway system deficiencies: lack of air conditioning in rail cars; escalator and elevator outages; and operator or equipment failures resulting in derailments and collisions -- along with injuries and fatalities.
Metro is attempting to rectify the system's deficiencies, attributable in part to human fallibility but also to chronically inadequate financing. Yet there is one other long-standing deficiency that gets little attention but needs substantial improvement: lighting.
At the moment, improving lighting is understandably of low priority because lighting has little effect on overall performance. And there is minimal funding for anything beyond light bulb replacement. But lighting inadequacies not only compromise the aesthetic quality of the system's exceptional architecture, they also adversely affect visual acuity and comfort and, at certain places, customer safety.
The Washington area is blessed with one of the world's most aesthetically memorable subway systems, designed by the late Chicago-based architect Harry Weese, who also designed the District's historic Arena Stage Theater. Metro stations are spanned by column-free, coffered vaults of reinforced concrete, recalling monumental edifices of ancient Rome and the fanciful 18th-century etchings of Giovanni Battista Piranesi. Seen regularly in subway scenes of movies set in the nation's capital, the subtly lighted, vaulted stations are by far Weese's most elegant and emblematic architectural contribution to Metro.
Lighting is a key element of Metro station architecture. The principal strategy was to conceal light sources and illuminate vaults and station spaces indirectly. Shielded lights running along the bottom edge of each vault vertically project light that subtly bathes the arching gridwork of ribs and recesses. Attenuated interplay of soft, reflected light and crisp shadows across vaults is ethereal, making the concrete structure appear delicate and almost weightless.
Through lighting, the Weese design team succeeded in creating a theater-like ambience verging at times on mystery. Gray-shaded areas contrast with occasional spots of intense brightness. Walking or standing on mezzanines and platforms, travelers experience feelings of being at once in an intimate and a communal space.
To augment illumination of vaults high overhead, some of the Metro-brown, triangular pylons standing on station platforms and mezzanines contain concealed floodlights that throw light upward. By contrast, floodlamps recessed in the low, flat ceilings of mezzanines provide illumination for spatially compressed platform areas below mezzanines.
Unfortunately, this strategy of aesthetically appealing lighting has produced too many places within Metro stations that are simply too dark. Insufficient foot candle levels in such places make it difficult for riders waiting for trains to read graphics and text on platform pylons, not to mention newspapers and books. Below mezzanines, one must stand directly under a recessed downlight to read anything. And platform spaces beneath escalators and stairs leading to mezzanines can feel especially ominous, a bit like lightless alleys where "lurking" comes to mind.
Escalators and landings, stairways and turnstile areas also can be too dimly illuminated. Even the station names affixed at regular intervals to the sides of vaults are sometimes hard to read because the lighting is too subtle.
In the interest of full disclosure, a few years ago I was a consultant helping Metro conduct a lighting design study. I quickly realized that introducing new lighting within stations would be difficult, and not just because of cost. The primary challenge is to preserve the essence of the original lighting concept and aesthetic character of stations, which could be easily undermined by inappropriate lighting retrofits. The form and structure of stations offer few places to install effective new light sources.
Thus, if and when Metro is able to mobilize resources to deal with the subway system's lighting problems, sensitive and creative design intervention will be needed. Otherwise, one of the most vital aspects of Weese's extraordinary architectural legacy could be in jeopardy.
Roger K. Lewis is a practicing architect and a professor emeritus of architecture at the University of Maryland.