Highway patrol.

Continuing the French tradition of building inventively with metal and glass, this motorway control centre is an imaginative response to a functional brief.

Scything through the outskirts of Paris, the Grande Axe connects the western suburbs with the city centre. From the hub of the Arc de Triomphe, the arterial motorway passes into a tunnel under the business district of La Defense to emerge in the suburb of Nanterre. It then crosses the Seine and streaks off into the leafy Parisian hinterland. The linear route defines a strong east-west axis and acts as the main gateway to the city. Odile Decq and Benoit Cornette were asked to design a new centre for the highway control agency which patrols the surrounding motorway network. Exploring notions of aerodynamism and material lightness, their response to an essentially functional programme imaginatively transcends the limitations of site and brief.

The new control centre is located below a motorway viaduct, at the point where the road emerges from the tunnel running under La Defense. The viaduct skirts along the western edge of Nanterre, through a featureless, melancholy suburban landscape of tall apartment blocks and elevated railway tracks. Decq and Cornette's strategy was to conceive the new building as an integrated extension of the motorway viaduct, rather than an isolated object. This involved reconfiguring the viaduct structure as a series of relatively slender curved steel arches (painted bold red), instead of the more usual massive concrete pillars. Suspended between two of the viaduct supports, the linear volume of the control centre appears to float weightlessly underneath the motorway, like a submarine stealthily stalking the traffic above. The rationale for hoisting part of the complex above ground relates to a more general programme of phased civic improvements. New landscaping and a park will eventually be constructed on a strip of wasteland to the south of the site, so it was considered important to minimize the impact of a potentially hermetic, monolithic structure.

Divided into two sections, the complex is organized to place vehicles below ground and humans above it. Detached from the main elevated volume, a secondary subterranean box houses garages, services and storage. Its roof forms a podium courtyard giving access to a small police station at ground level. Facilities for highway patrol staff, such as cellular offices, conference areas, and radio control rooms are contained in the suspended upper floor. This level is arranged in a simple U-shaped plan, with the sharply chamfered glazed ends of the two wings resembling a pair of giant, ever-watchful eyes. An enclosed glazed bridge unites the wings at their mid point, both facilitating and expressing circulation. Clad in horizontal panels of glass and aluminium, the long lateral flanks of the building are overlaid with an external carapace of perforated metal louvres that function as motorized brise-soleil.

Emphasizing kineticism and lightness, the sleek, aerodynamic forms are clearly inspired by the poetry and power of moving bodies. Hearteningly, despite occupying a virtual no man's land, the building appears well cared for. Decq and Cornette's appropriation of industrial materials and the evident relish and care in the way these are put together reflects an affinity with the sophisticated exploration of structure and tectonics most obviously characteristic of High Tech, but it also extends the French tradition of building inventively with metal and glass begun by pioneers such as Prouve and Chareau. The only minor cause for regret might be that because of its remote location and determinedly non-public function, the control centre seems destined to remain an undiscovered gem.

Architect Odile Decq + Benoit Cornette, Paris

Photographs 3, 6, X. Testelin

Others courtesy of the architects