GLASGOW benefits from the most extensive suburban railway network outside London, but suffers from one major defect:

the gap in rail services across the City Union (Crossrail) Line, a short 1.8-mile double tracked route, which is yet to be electrified. This line has the potential to facilitate direct train journeys from Ayrshire to Edinburgh, but is currently only used to move electric stock hauled by a diesel locomotive to and from Shields Road Depot.

At peak hours, traffic flow across the city's Kingston Road Bridge highlights the fact that many commuters travel daily to and from destinations stretching from Ayrshire, Renfrewshire and Inverclyde to North Lanarkshire, West Lothian and Edinburgh.

In a strange contradiction, while use of public transport is strongly encouraged by the Scottish Government, electrification of the Crossrail route has recently been removed from Network Rail plans, leaving the "travel barrier" between the city's two principal stations - Glasgow Central and Queen Street.

Presently some 16 million annual rail journeys are made on the electrified routes in Ayrshire, Renfrewshire and Inverclyde, but these routes can only operate as far as Glasgow's Central station. Rail growth on these South West electric routes is only half the Scottish average.

While the service is primarily a commuter line, research by RailQwest has shown that a minimum of 12% of daily journeys are made between locations as diverse as Prestwick Airport, Irvine, Livingston, Airdrie, Shettleston and Greenock. Given the option of a direct rail service via the Crossrail Line there is potential for upwards of 1.5 million annual rail journeys following electrification.

The need for a cross-Scotland service is acknowledged by First Scotrail's plan to introduce a "direct" service between Ayr and Glasgow from next summer.

Unfortunately this will require reversal of trains at Glasgow Central and routing via Carstairs, serving only a potential market of 80,000 on the Glasgow-Carstairs-Edinburgh sector.

By operating the service over an electrified Crossrail route, stations in East Glasgow, Airdrie, Coatbridge, Bathgate and Livingston would provide a considerably larger market potential of 279,000.

The Scottish Government's recent acquisition of Prestwick Airport will further strengthen the case for a cross-Scotland rail service, utilising Prestwick's unique rail link. A future second phase would see the construction of three new stations on the Crossrail route at West St (interchange with the subway), Citizens (serving Hutchestown & Laurieston), and Glasgow Cross (interchange with the Argyle Line).

Several comparative rail electrification schemes, such as the five-mile, single track Paisley Canal line, already exist in the West of Scotland.

It is hoped that strong representation from Glasgow and the West of Scotland will promote the Crossrail electrification as the first phase of a what must be the most obvious rail infrastructure project in Scotland.

Ian Richard is chairman of RailQuest lobby group