Officially, public policy encourages greater use of buses as a means of reducing both pollution and congestion. Therefore, it should worry us that the three biggest bus operators in Glasgow are warning in The Herald today that the city faces years of traffic chaos during the redevelopment of Buchanan Bus Station. Moreover, many believe the end result will be an inferior facility unlikely to attract extra passengers. The dubious objective of all this disruption is to double the size of the Buchanan Galleries, transforming it into one of the largest shopping complexes in Britain at the very moment when the nation's shopping habits may be changing.

Officially, public policy encourages greater use of buses as a means of reducing both pollution and congestion. Therefore, it should worry us that the three biggest bus operators in Glasgow are warning in The Herald today that the city faces years of traffic chaos during the redevelopment of Buchanan Bus Station. Moreover, many believe the end result will be an inferior facility unlikely to attract extra passengers. The dubious objective of all this disruption is to double the size of the Buchanan Galleries, transforming it into one of the largest shopping complexes in Britain at the very moment when the nation's shopping habits may be changing.

There are several specific areas of concern. The first is that only weeks before the developers are due to submit finalised detailed plans to the city council, those running the city's bus services are unconvinced that properly thought-out alternative arrangements have been prepared for the two-year construction phase. During this time, the current bus station will be demolished and replaced by a covered facility under a multi-storey car park. The experience of Edinburgh suggests this could be a recipe for confusion and delay. This risks reversing several years of encouraging growth in the use of buses. Reliability is the key to a smooth-running public transport system. Disgruntled passengers soon form new travel habits and are unlikely to revert later. The situation is particularly challenging for First, the biggest operator, with 6000 departures a week, and carefully timetabled 20-minute berthing slots that cater for late arrivals and staff breaks.

For all the bright talk in the plans of a "state of the art integrated public transport hub", the old adage of "if it ain't broke " surely applies to Buchanan Bus Station, a well-run, pleasant, open-air facility with room for taxis, drop-offs and vehicles resting up before departure. Experience elsewhere suggests that, in spite of various assurances about lighting and ventilation, an enclosed space full of noise, fumes and vibration does not represent an improvement. And room for expansion would be limited. Research suggests that, given the right conditions, bus travel could expand by 4% a year. At that rate, spare capacity soon would be exhausted.

Glasgow used to have one of the lowest levels of car ownership in Britain. In recent years, those rates have risen sharply, though recently actual car use has flattened off. Nevertheless, congestion is such that it was easier and quicker to travel into the city centre in Victorian times than today. This represents a massive failure of transport policy, particularly the lack of major park-and-ride facilities at stations and bus deregulation, which has turned Renfield Street into one of the most polluted thoroughfares in Europe. Now this bad situation may be about to take a turn for the worse, as bus operators cope with the logistical nightmare of life without a bus station. And the cause of this disruption is a massive retail development based on the assumption that the public has an ever-expanding appetite for tramping around massive shopping centres. Examples like the notorious Birmingham Bull Ring should remind us that mistakes can take years to put right. Meanwhile, the worthy goal of an integrated, ecologically sustainable public transport system remains as elusive as ever.