Glasgow, the largest city in Scotland, has the world’s third-oldest underground metro system. Only London and Budapest boast more experience in lugging people about their merry way below our feet.

And Glasgow manages to do this with a stunning simplicity. Opened in 1896, its Subway route is circular, with two lines (“inner” and “outer”) circumnavigating a loop which twice crosses the River Clyde. The network (a term I use loosely) links 15 stations, and runs from the city centre to the West End, and across to the South Side.

In all, the seven mile route takes approximately 25 minutes to complete. In 2013-2014, the Glasgow Subway averaged almost 35,000 passengers daily – around 12.5m each year.

The existing network. Image: SPT.

So, the network is a simple one. But it could have been a lot more complex if the visions of a few Strathclyde Partnership for Transport (SPT) chiefs had come to pass a decade or so ago.

In 2007, a “feasibility study” outlined the SPT’s desire to expand the Subway network before the 2014 Commonwealth Games came to town. The plan would have involved creating a second circle, covering the east of the city, where the newly created Emirates Arena and Athlete’s Village were to be housed.

At the time Alistair Watson, a Labour councilor, released a statement promising:

“We will deliver the East End extension for 2014. I am being unequivocal about that.”

Unequivocal, no less.

The proposed line would have interchanged with the existing network at its busiest station, Buchanan Street (which connects with the Queen Street mainline station), as well St. Enoch’s station. There would have been seven new stops, too, including Celtic Park. The whole lot was projected to cost £2.3bn.To research the project, in 2007, SPT executives flew to New Delhi to learn more about their underground set-up and transport preparations ahead of the 2010 Commonwealth Games.

Despite this promising maneuver, no extensions ever materialised beneath the streets of the East End.

An extract from a 2007 leaflet showing the proposed extension. Image: SPT.

That’s a shame. Because Glasgow boasts an abundance of very usable and intact underground tunnels and old railway lines, some of which would have been re-used in an East End extension. Throw in road improvements and some new cycle routes, and there would have been clear benefits for a fairly tattered and beaten up part of the city.

The area certainly did benefit from hosting the Commonwealth Games. According to a post-games survey, the residents of Glasgow’s East End, where much of the regeneration activity was focused, welcomed the physical improvements to their neighbourhoods, and “felt safer living there than they had before” after a post-2014 Games survey. Venues like the Emirates arena have attracted more events to the city, and an estimated £18m worth of new contracts have already been credited to the 2014 Games’ legacy.

And SPT’s “Subway Modernisation Programme” is very much in full swing. Some £270m has been spent or set aside for improving stations across the existing network, and the introduction of a Smartcard system has proved popular amongst travelers. It looks a lot better, too, with a chunk of the 1970s stylings now gone from the city.

But there remains a widespread feeling of frustration. The Commonwealth Games seemed to be the perfect opportunity – the perfect excuse – to radically upgrade Glasgow’s Subway system. But the city missed it. Only time will tell if this bold and radical idea will rear its head once more.