By Dr Christopher Harvie

WHEN I was in Holyrood I "wasna a gude bairn", to coin a phrase, but I held my peace and worked privately to help get the (partial and not very satisfactory) Edinburgh tram from Princes Street to the airport. Waverley-to-Leith was always the main line. I have that on Alex Salmond's say-so and I'm glad the Edinburgh SNP Group now agrees with him.

But the £145 million estimate for a 4 km York Place-Newhaven line seems unreasonably high (compared, say, with the similar cost of a 14km tram-train from Glasgow to its airport, or the 2012 electrification of the Paisley Canal railway line: only £12m). I sense the bony but uninformed hand of The Scots Accountant. Lower costs are possible; these will encourage further expansion.

If Tuebingen – the size of Perth – can budget for its planned 10 km town tram at £8.1m per km, and Nottingham, advised by Germany's remarkable Karlsruhe, costs £20m per km, why can't Edinburgh act likewise? Why has there been no attempt to facilitate bus/tram co-ordination (at Maybury, Edinburgh Park, Haymarket) redesigning halts so that buses and trams can – as in Germany – share platforms and transfer passengers? That way Princes Street can be rescued from its present state as a public transport-only traffic jam.

The problem – figuring much in the fourth edition of my No Gods and Precious Few Heroes: Scotland, 1914-2015 (Edinburgh University Press: spring 2016) – is our Scots construction-obsession: creating "joabs oan ra tarr". A disturbing report by the Chartered Institute of Building into UK public works procurement published in late 2013 found that a tight cartel had been allowed to expand at the cost of manufacture/maintenance and transparent tendering.

If Edinburgh already has the rails and up to 10 spare trams, and has (painfully) done much of the Leith foundation work, why this expense? German systems that I know well have come in on time and on (far lower) budgets. Tuebingen has expanded bus passengers tenfold from 1980 to 2010 to pave the way for its Stadtbahn. A 20-minute frequency on the main route – station-university-clinic-highrise scheme – has now become a bus every four minutes.

The cost of two long new lines in Ulm and Mainz is (per km) less than half that of the 4 km York Place-Newhaven line. In contrast to the success of, say, the Black Forest's tram-trains and Kulturbahn cycle-trains, Scotland's overall record is unpromising. Edinburgh's air quality remains poor, the stations between Bathgate and Airdrie and on the Borders line are over-engineered and awkward to use. Bus-rail "co-ordination" under Margaret Thatcher's daft 1985 Transport Act is, with a few exceptions, a bad joke.

Success in whittling down inflated tenders and spreading the geld will open up new long-term perspectives. Transport Secretary Derek Mackay has been positive about this in the Glasgow Airport and Edinburgh context; he might envisage combining forward planning with Dublin where the Irish are now reviving their airport metro scheme to add to the success of their Luas trams.

A rationally-costed Leith line could help set Edinburgh up for a Bridges-Infirmary/Shawfair-South Suburban tram: relieving Princes Street and extending into Lothian. There's also the chance to re-engineer Fife: not just through a revived Leven branch. What’s to be done with the soon-to-be redundant Longannet lines from Alloa to Dunfermline? Why not a Stirling-Alloa-Culross-Dunfermline-Cowdenbeath-Glenrothes-Markinch-Leven tram at 750v DC? This can provide "heads of the bridges" bus and rail interchanges, while a line over the Forth Road Bridge to the airport would conserve the bridge and link with the Edinburgh system. Other tram-train possibilities include the Deeside to Dyce/Ellon corridor through Aberdeen and a Leuchars-St Andrews shuttle.

There's a good precedent in the conversion in 2000 of the 44 km Karlsruhe-Heilbronn railway into a tramline. For Baden-Wuerttemberg, good and very cheap public transport carrying over a third of passenger movements is the fastest "social saving" generator the it has got, pumping investment into the skills and machines of Europe's prime manufacturing region. Its 12 million people export more by value than the whole of the UK.

Otherwise "more roads, bigger cars" leads unerringly only one way: over Clarkson’s cliff.

Dr Christopher Harvie has been Professor of British Studies at Tuebingen since 1980, and is a former Kreistag (County Council) candidate for the SPD; he was an SNP MSP, 2007-11, and President of the Scottish Association for Public Transport, 2002-11.