Bus stop.

A successful attempt to moderate and humanise the scale of a very large structure for a normally inhospitable and unpleasant building type.

Niels Torp's design that won the competition for the Nils Ericson Terminal at Gothenburg had a bold and simple parti. A long glazed gallery stretched due north from Edelsvard's elegant nineteenth-century Gothic railway station; it ran between the car park to the east and the bus manoeuvring area in Nils Ericsonsplats. The axis of the gallery was continued in a new railway terminal, then across Edelsvard's station concourse to the tram stop in Drottningtorget (Queen's Market Square): all terrestial forms of transport were united in one bold move. The section of the new terminal building (which was to contain offices as well as booking hall, restaurant and so on) was carefully organised to avoid being seen over the old train shed from Drottningtorget. Nils Ericsonsplats was to be simply landscaped as an extension of Gothenburg's complex of green urban spaces.

In fact, only the bus-station gallery has been built so far. And, as Torp says, 'For some unknown reason, the intention to refurbish Nils Ericson square as a well-defined urban space and a prominent forecourt to the terminal ... proved hard to achieve. The design process was taken over by other architects, and the original concept was lost in the interplay between several actors'. Yet another case of an architect from one Scandinavian country (Torp is Norwegian) finding difficulty in executing his competition-winning design in another? Equal difficulties faced the creation of the terminal block, intended to link the gallery to the railway station. So the gallery, vestigially connected to the station, exists as phase one of an uncompleted and partly botched grand design.

But what has been made amply justifies the jury's decision to give Torp the first prize. The building has great clarity, and makes an important contribution to the city's urban spatial network. Several people have suggested a relationship to Grimshaw and Hunt's Waterloo Channel Tunnel Terminus (AR May 1993), and they are right in some respects, for the basic structures of the two are very similar: eccentric three-pinned arches formed of two bow-string trusses. But the Gothenburg structure is very much more simple because it does not have to taper and curve in two planes, nor flex to cater for the dynamic loads of extremely heavy trains. And it avoids Waterloo's only obvious problem - having the large truss within the envelope with most of the small one exposed, a solution which (for all the breathtaking refinement of the general idea and detailing) has a certain clumsiness.

Unlike the great train shed, Gothenburg's bus station has to be sealed against the elements - at Waterloo all the ticket purchase, waiting and shopping is below platform level in an efficient but not very inspiring layer, squashed between the tracks and the top of the viaduct; the only times when travellers are actually in the glazed volume on the platforms is when they bustle between trains and subterranean purlieus. At Gothenburg, all activities take place on the same level, and travellers wait in the glazed space, so it must provide equable internal conditions in Gothenburg's climate (gentle for Sweden, but wet, windy and harsh compared to most of the rest of Europe).

The roof is handled in two different ways. Over the shorter eastern trusses on the entrance side, the glazing roughly follows the curve of the compression boom (which is on the upper side here); an ingenious bracket detail links the frames of the stepped cascading glass to the structure. The longer, western trusses, with straight tension booms on their upper sides, carry strips of flat roof separated by clerestories. Below the roof strips are curved panels of perforated metal which deflect downwards some daylight, act as diffusers for artificial illumination and give a detailed sense of scale.

One of the architects' central concerns has been to give the great length of the building (in a way it could be endless) a sense human scale and place (or rather linked places). The basic rhythm of the building is of course given by the 6.6m bay structure, with the western trusses bearing onto massive in-situ concrete plinths that are projected outside to give a horizontal rhythm that orders the bus stances, and internally clearly demarcates the boarding gates. The eastern trusses bear on much less obtrusive supports. On this side, the length is broken up by inserting small shop units in the middle of the structural bays. The shops are grouped in banks, and between these are the three eastern entrances.

You come in on this side from the car park and taxi set-down area. The aim is to make the process of transition into the big glass shed as agreeable and undaunting as possible. A long, almost free-standing canopy of glass and steel shelters visitors from the elements; the mass of the building is broken down by projecting the shop units out through the machine-made aluminium and glass skin. Each projection has a slightly battered grey granite base topped with solid warm wood, divided almost into courses by raised horizontal strips. There are obvious abstracted echoes of rusticated masonry pylons (without any vulgar flavour of PoMo); the handling and strong modelling of materials introduces a human measure into the big structure, as the Ancients did with their great buildings, The entrances are trabeated granite portals, made of huge almost primitive slabs with their long sides (the ones you go past and touch) left rough. These lead to the frameless glass boxes of the wind-porches that give you a first taste of the big volume.

The exit gates to the buses are similarly made in traditional materials; here heavy and welcoming wood, similar in detailing to the structure of the shops opposite. The luminous gallery space is informally divided by permanent light wood seating and large indoor trees, set in a rhythm that counterpoints that of the structure. The chain of places is without distinct focus, but at the southern end, the arcade widens at the Tidpunkt (time point), a volume enclosed in sheer glass, where tickets are sold and information can be obtained. The punkt seems absurdly small for a building that caters for 20 000 people a day, but of course, most of them use bus passes, and the area is supposed to be only the connection to the (as yet) unbuilt terminal link. When (if?) it is completed, Gothenburg's bus station will rival in elegance and understanding of travelling humanity the one built in Stockholm some years ago by Ralph Erskine and others, which demonstrated how this usually dismal twentieth-century building type can be made into a decent and enjoyable part of the city (AR December 1989).

All public travel interchanges tend towards the condition of airports, and this is not entirely a bad thing, for it keeps the pollution and unpleasantness of big engines as far as possible apart from the intimate human world. The problems of most airports are confusion and formlessness. The clarity of the Nils Ericson bus station avoids this, yet it also escapes the monotony and institutionalism that curse many big public buildings of simple parti: architectural skills of a high order have been at work.