Past schemes for reopening the Shields Junction to High Street Junction link line, "The City Union Line"  have concentrated on linking electric services from Airdrie to termini on the south bank of the Clyde such as Gourock, and the needless construction of a link to allow access from the City Union line into Queen Street Low Level.  These plans provide only limited additional journey potential.  The scheme suggested below would allow an integrated North to South rail transport system for the first time in Glasgow's history.
The main feature of the scheme is that it uses the entire "City Union" route from Cowlairs via Springburn and Bellgrove to Shields Junction instead of only the southern half, and with the addition of two new spurs and the re-opening of a third, the possiblities arise for services from any of the main routes converging from the South to be routed over the revitalised link to reach all the main routes radiating to the North.

Construction would be required at the following locations

1. The pair of former freight only tracks between Bellgrove Junction and High Street would be relaid as fast lines bypassing Bellgrove Station, and Bellgrove Junction remodelled.  At High Street these tracks would take a new formation to reach the existing freight only tracks to Shields Junction.
2. The existing Airdrie to Queen Street Low Level tracks would be realigned through the former Barrack Street Freight Terminal to burrow under the new link and rejoin the existing route at High Street Station.  This would provide a grade separated junction preventing congestion where these two routes cross.  Crossovers would be provided to link the two routes.
3. A new "Trongate" Station on the link as shown, linked to Argyle Street Station by an ariel passageway similar to that employed at the SECC
4. Re-instatement of the former G&SWR line from Gorbals Junction to Strathbungo junction.
5. A new "Gushetfaulds Spur" connecting the Crossrail Link with the West Coast main line, built through the currently derelict site of the Gushetfaulds Freightliner Terminal.
6. Reopening Shields Road Station as a new interchange between Glasgow to Ayrshire (& any future Glasgow Airport) services and services over the Crossrail Link, with a link to Shields Road Underground Station
7. Interconnection to the current routes to Ayrshire and Renfrewshire lines to provide possible onward through services.
8. New connection in the Garngad area to provide access to the Crossrail Link from the former Caledonian Main line from Cumbernauld.

Suggested new service pattern

1. Three services which would dovetail nicely together would be the Maryhill to Queen Street, Springburn Branch and Paisley Canal services.  These would be combined as a through Maryhill to Paisley service.  To prevent congestion between Springburn and Bellgrove this service would only stop at alternative stations on the Sprinburn Branch (ie Springburn or Barnhill and Alexandra Parade or Duke Street), with other services picking up the missed stops.  Current existing Springburn Branch electric services could be diverted to terminate at Shettleston
2. Edinburgh to Glasgow trains would run via the link and the new Trongate Station to Shields Road and if required work empty to Corkerhill for stabling between duties. Selected services could work through to other termini.
3. Aberdeen, Inverness and West Highland Services would run via the link to the new Trongate Station and possibly then on down the Gushetfaulds spur to the WCML and terminate at Motherwell, giving connections into and out of services to the South.
4. Cumbernauld/Stirling and Falkirk services would be cross linked into East Kilbride/Barrhead and Kilmarnock services via the reinstated G&SWR link from Gorbals Junction to Strathbungo Junction, calling at selected Sprinburn Branch Stations.