In "The Legible City" by Jeffrey Shaw the visitor is able to ride a stationary bicycle through a simulated representation of a city that is constituted by computer-generated three-dimensional letters that form words and sentences along the sides of the streets.

The research and development of various mechanisms and codes of spatial representation has been a major preoccupation throughout the history of Western Art. The application of three dimensional computer imaging technologies in this context has a revolutionary meaning. Instead ofthe traditional activity of art as a representation of reality, the artwork can now become itself a simulation of reality within which the viewer's point of view is located. "The Legible City" is a first example of the possibility of the digital image to evoke a three dimensional virtual space which the spectator can enter and explore.

The spectator is able to use a bicycle to interactively travel in a video projected three dimensional virtual image space. In the first realized version of this work the image space in which the bicyclist can travel is based on the ground plan of part of Manhattan, New York - the area boundaried by 34th and 66thStreet, and Park and 11th Avenue. Using real-time computer graphic technology, the city visualised by solid three dimensional letters that form words and sentences along the sides of the streets. These words and sentences conform tothe actual plan and scale of this city - its particular organisation of streets, avenues, intersections, parks, etc. Thus the actual Manhattan architecture of buildings is completely replaced by a new architecture of text.

Travelling through this city of words is consequently a journey of reading. Choosing direction, choosing where to turn, is a choice of the story lines and the user's position. In this way this city of words is a kind of three dimensional book which can be read in any direction, and where the spectators construct their own conjunction of texts and meanings as they bicycle their chosen path there.

The image of the city is video projected onto a large video screen in front of the bicyclist. The bicycle is fixed on a platform in the installation, but the spectator controls his / her speed and direction of movement in the projected image space by pedalling faster or slower, and by turning the handle bars. The virtual world where the bicyclist is travelling simulates faithfully the experience of bicycling in the real world.

In this work the city is constituted physically by the three dimensional arrangement of words into streets, and the city is constituted psychologically by the meanings these words carry as they are read by the bicyclist travelling through these streets. The texts have been written as eight separate storylines that have a particular relationship to Manhattan - for instance monologues spoken by Mayor Koch, Frank Lloyd Wright, Donald Trump, Noah Webster, a cab driver, a tour guide, an ambassador, etc. Each storyline has a specific location in the city, and each is visually identifiable by the particular colour of its letters.Thus the bicyclist / reader can follow one story line by following its colour, andalso recognise higher shifts from one storyline to another because of the colour changes.

Directly in front of the bicyclist, a small video screen shows a plan of Manhattan, and the actual location of the bicyclist there by means of a flashing dot that represents the position and direction of movement. Electronic devices attached to the steering wheel and pedals of the bicycle measure the rotation of the steering wheel and speed of pedalling. Responding to this formation, the Manhattan database is interactively calculated and displayed by a Silicon Graphics Personal IRIS graphics computer. Video output from this computer goes to a video projector which shows the image on the large screen in front of the bicyclist. Another personal computer handles the small video display of the plan of Manhattan and the indication of the bicyclist's position there.

The authors of this work intend to realise more versions based on the ground plans of other major cities. What is felt to be interesting are the different formal geometries of these cities' plans, which will strongly effect the character of their lettered visualisation. Furthermore, each city's plan and historical identity asks for a different approach to the content and writing of the text.

"The Legible City", as it now has been created, is in a fundamental way determined by the capabilities of state-of-the-art computer graphic visualisation technologies. The ongoing and rapid evolution of these technologies generates new capabilities that are significant to future developments of this work. For instance utilizing NASA's stereoscopic head-mounted display, the bicyclist would experience the work as a totally surrounding three dimensional space of imagery.