Scotland's largest city is to launch a new push to complete its motorway network with even wider support than before. For there are two main transport concerns for Glasgow which threaten to compound each other.

One is the effect of the Scottish Parliament on attracting business eastwards, and the second is the long-standing problem of Glasgow's ''motorway box''. The box remains incomplete without an extension to the M74, linking with the M8 and providing a second motorway route across the Clyde.

For companies in west central Scotland almost every movement of material is through the centre of Glasgow. The new ''Complete to Compete'' campaign has attracted wide support for extending the M74.

Congestion on the single M8 link makes it increasingly less reliable. Many companies have brought forward their latest cut-off times at the despatch bay to be sure of connecting with aircraft, trains or ships, so that less of the day's manufacturing can be allocated to time-definite sales.

The same is true of sectors such as whisky and of raw materials moving north and west into Renfrewshire, Inverclyde and Dunbartonshire. Industry throughout Scotland is affected by the road infrastructure in Glasgow.

Chamber chief executive Peter Burdon, right, also believes rail services to Edinburgh must be doubled to every 15 minutes. ''This would make it a more efficient option of the business community,'' he said. ''If it is easier to move between Glasgow and Edinburgh then the drift east is less likely to be a problem.

''We must avoid the marginalisation of Glasgow at all costs. The siting of the Scottish Parliament in Edinburgh obviously places the capital at an advantage. However, with adequate transport links we believe that the drift east can be curtailed.''