Its two gigantic pillars on either side of the the Seine estuary will support a steel structure of striking elegance and grace, longer than the Champs-Elysee and as high as a Manhattan skyscraper.
What keeps the engineers awake at night is the fear that bad weather sweeping in from the Atlantic will rip the bridge apart at its most vulnerable stage - just before the spans meet in the middle. With typical sang-froid, however, the engineers say this is the worst- case scenario.
The bridge, whose construction began in 1988, is part of a grand French plan to link Le Havre with the new autoroute between Calais and Nantes. Whether its size is justified is another matter, as another bridge spans the Seine at Tancarville, 20 miles away.
Doubtless truckers, commuters and tourists will be happy to avoid the constant traffic jams up-river. And for British tourists driving south from the Channel tunnel, the bridge will be a boon, enabling them to avoid the busy main roads converging on Paris.
The cost to the French taxpayer is an astronomical 2 billion francs ( pounds 235m), but drivers will be charged a mere 30 franc toll per crossing. Cyclists and pedestrians will have their own lanes, though not many of the latter are expected regularly to tackle the walk.
The structure is a triumph of peculiarly French logic over matter-of-fact concerns about how to cross a given stretch of water. Following in the footsteps of such giants of engineering as Gustave Eiffel, the bridge's engineers are taking what appear in theory to be formidable risks. When Eiffel unveiled the drawings of his tower, few people believed that it would remain standing.
The engineer knew, from his calculations, that it would. But to keep everyone happy he added huge arched sections below the first stage of the tower; these give the impression of greater strength, but are, in fact, purely decorative.