There's something about bridges that makes them irresistible to the mysterious people who plan and promote regeneration projects. They look purposeful; you can see what they're for. Architects and engineers like them too, as they provide a pretext for white parabolas and straining wires, in the style of the Spanish-born, Swiss-based architect-engineer Santiago Calatrava, as if the task of taking a path across water were the most difficult and unprecedented in the world. "To each rivulet its own Calatrava," wrote Rem Koolhaas once, scathingly.

There is an alternative way of conceiving bridges: rather than spectacles of structural gymnastics, which invite you mostly to gawp, they can be places to inhabit and linger, city streets or squares that happen to be placed above water. Such places – for example, the Ponte Vecchio in Florence or old London bridge – capture the imagination, but modern attempts to recreate their qualities are rare.

The Scale Lane bridge in Hull is not quite at the same scale as these great precedents, but it has the same idea – that a bridge is a place, not equipment. It includes on its steel forms a curved array of seating, south-facing and wind-sheltered, like a seaside esplanade. It has a restaurant (unfortunately untenanted) and a raised circular platform for enjoying the view. You can take two routes around it, one stepped and the other ramped, and it flows from a section of land-based street relandscaped as a series of "garden rooms".

Scale Lane bridge is not just a way of getting from A to B, but something in itself. It's not a gleaming white rebuke to its industrial surroundings but – robust and black – an extension of a place where, as one of the bridge's architects says: "Even the mud is beautiful."

As well as being a place, it's an event: it has to open from time to time to accommodate the traffic on the river Hull (a small tidal tributary of the mighty Humber), which it does by pivoting around a point on its westward side. Locally it has been compared to a pinball flipper, but its motion is more sedate. Unusually, possibly uniquely, the public can ride on it as it rotates, and, on one side, step on and off while it moves – the speed is slow enough to make this safe. And it's a special thing, to be held up by this ship-like piece of steel while the world turns around you. A light-and-sound installation turns the warning systems into part of the experience.

The £7m bridge is the work of the contractors Qualter Hall, the engineers Alan Baxter Associates and the architects Jonathan McDowell and Renato Benedetti, who (although they design other building types) have a niche conceiving bridges as places. In 1997 they were shortlisted alongside much bigger names for the Millennium bridge in London, and their design, although less dazzling than the Norman Foster version that was eventually built, would have offered a more enjoyable journey across the water. In 2008 they completed a 130m pedestrian bridge in Castleford, where (as in Hull) the purpose was regenerative.

Hull is the city whose misfortune is to sit on a word ladder between dull and hell, and whose associations with Philip Larkin and John Prescott link it to misery and unloveliness, most of which negativity is unfair. Its medieval street pattern carries fine Georgian and Victorian buildings, and it has a beautiful almost-cathedral, and an inspiring watery setting. But, like almost every other industrial town, it suffers from lost business and jobs and empty spaces of the kind that provoke a persistent political itch. In the belief that Something Must Be Done, Hull has been garlanded with the aquarium known as The Deep, another bridge not far from the swinging one and four shopping centres, whose main effect is to suck life out of the town's existing streets and markets.

Conceived in 2005 by the now defunct agency Yorkshire Forward, the bridge's purpose is to link the town centre to a hoped-for development on the other side of the river, and to be, inevitably, an icon. Equally inevitably, the development has fallen foul of the recession, bar a big car park with an achingly ugly Premier Inn on top. Sceptics might point out that it does indeed not go from A to B, as there is not much B there. It has been called the Bridge to Nowhere. It has also been criticised for being about three years late, for reasons that include the demise of Yorkshire Forward.

Yet people are using it, and pausing there, and inhabiting it, as intended. In the long run, its purpose is likely to be fulfilled. Meanwhile, it's a strength that it is not just another gawp-at-me icon. These look foolish when they lead only to weeds. By making the bridge a destination in its own right, McDowell and Benedetti have at the very least created a good place to pass the time, while waiting for the mirage of regeneration to become real.