Glasgow Airport serves over 8m passengers and 100,000 planes every year. It’s the eighth busiest airport in the UK, and the second busiest in Scotland.

But on one not entirely flattering measure, it ranks as number one: it’s the largest airport in the country without a fixed rail link.

This is, all told, a bit rubbish: getting from the airport to the city centre, 10 miles east, either involves driving, getting a cab, or taking the Glasgow Airport Express bus, which runs back and forth to Buchannan Bus Station at all hours of the day or night.

First Group, which runs the latter, has done its best to make it as un-bus-like as possible, offering free wifi, USB charging points and so forth. But you are still, fundamentally, on a bus on the M8, which is not necessarily what you want after a long flight.

And the convenience of that motorway, which lies immediately south of the airport, is “both a blessing and a curse”, says Ross Nimmo, the head of planning and development at Glasgow Airport. “That motorway is pretty busy. You can’t tell if it’s going to take you 20 minutes or 1 hour and 20.”

So, for several decades now, the local authorities have seen the addition of a new rail link as the key to growing the airport’s traffic. The first feasibility studies into the project were published all the way back in 1990. By 2006, that had evolved into a proper plan to build a new spur of the railway line from Paisley.

By 2009, with the global economy burning around us, the Scottish government had cancelled the project again. Which is just great.

The 2006 plan. Image: Scottish Government.

As it happens, finding around £200m to pay for it wasn’t the only problem with the scheme. There were concerns that it would chew up a lot of land currently occupied by much-loved things such as playing fields in the northern part of Paisley, as well as increase congestion on an already crowded line. It would also do a poor job of plugging into the broader Scottish rail network: Glasgow Central is served by trains from south and west of the city, but is annoyingly inconvenient for much of the rest of Scotland.

So when the project was revived as part of the £1bn Glasgow City Deal, the authorities decided to take a different approach. Instead of bog standard heavy rail, the new link will be a tram-train. At Paisley, it’ll diverge from the existing line onto a new light rail route to do the last kilometre or so to the airport.

That way, it’ll swallow less land in Paisley, so be less disruptive to the locals. It’ll also be cheaper, costing an estimated £144m, significantly less than the £210m+ the heavy rail link was expected to cost ten years ago. It won’t, best one can tell, but any more convenient for destinations beyond Glasgow Central in the short term, but the fact tram-trains can switch to on-street running means it is at least possible to connect it to other parts of the city centre at some later point.

Artists impression of the new link. 

The four tram-trains per hour will cover the distance between the airport and the city centre in just 16.5 minutes, stopping once at Paisley Gilmour Street en route. Which definitely sounds a lot better than that stuck-in-a-bus-on-the-M8 thing.

There is one downside, though: the new link is not expected to be operational until 2025. As Nimmo points out, Paisley is at time of writing still in the running to be the UK City of Culture in 2021. “To then wait four years for the rail link…” he says, rolling his eyes.

Would it be possible to build it any quicker? “All the land is owned by a national transport agency, local authority or the airport itself. The budget is there. The figures are fantastic.” We shall see.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

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