YOUR editorial (May 13) was absolutely right to criticise the spurious facts which Scottish Enterprise have used to try to bolster the case for the M74 northern extension. Extravagant claims of 6000 jobs lost if the road is not built will require the fullest possible scrutiny to assess the validity of the methodology used, but so far the consultant's report remains predictably confidential.

More fundamentally, this assessment of the economic impact of the M74 will remain worthless until a dispassionate comparison is made with the economic benefits of alternative uses for the #170m investment required. At no stage has the ''Complete to Compete'' lobby made any attempt to examine the impact of an alternative transport package making better use of the existing M8 (for example through the creation of HGV and bus priority lanes) while also investing in a Glasgow Airport rail link, modern freight railheads in Renfrewshire and Inverclyde, and new rail services across Glasgow.

Having disputed the economic benefits, it is odd that your editorial then concludes that it is a ''nonsense'' that the M74 northern extension has been postponed for so long. Given the experience of the M25 and countless other new motorways which have created more congestion problems than they solve, why should we automatically accept that a road conceived in the 1960s has any relevance to the transport needs of the twenty-first century?

Common sense dictates that the Scottish Office roads review should look at all the transport options along the M74 corridor and find the best mix of transport modes to meet the economic and environmental needs of the area. To do otherwise would make a mockery of the Government's claims to want a sustainable transport strategy.

David Spaven,

Chair, TRANSform Scotland,

72 Newhaven Road, Edinburgh.

May 14.