Leaders of both Edinburgh and Glasgow city councils came together this week to launch a campaign for investment in a major cross-border project - a High-Speed Rail (HSR) link to London.
Since 2003 Eurostar has run HSR through the Chunnel into St Pancras. The UK Government's spending review has blessed extending this as far as Manchester and Leeds. But continuation from there into Scotland remains up in the air.
This week also saw oil prices surge beyond $85 a barrel for the first time since the price spike in 2008. If oil were to regain $150 a barrel, as it did then, any cosy economics of short-haul flights to London based on today's prices would be gone. Even the pro-air Freedom to Fly Commission concedes that: "If there are dramatic improvements in rail services to the north west and Scotland, people may be attracted to switch from air for domestic journeys."
So, is there a case for HSR across the Border? It has been demonstrated by decades of practice in Europe that rail journeys up to four hours are competitive with air travel on journey time, especially when time for checked baggage, queuing or the inferior punctuality/reliability of air travel is considered.
Air traffic between Paris and Brussels or Frankfurt and Cologne no longer exists and HSR acting as "feeders" into long-haul airports now supplant most short-haul flights as one stage of a longer journey. On London-Paris travel, Eurostar carries over 90 per cent of passengers.
So, would these economics apply to Scotland? Certainly, both Glasgow and Edinburgh lie in the 400-mile/four-hour "window" that makes HSR most viable. But, given our more rugged terrain and the engineering costs to overcome that, would enough passengers use it to make economic sense?
At present, some six million cross-border train passengers use our two existing lines and around 7.1m air passengers travel from Scotland to the main English airports. A doubling of the market is therefore possible. But when we add in the factor that both rail and air travel between Scotland and England have doubled in the last decade, a 150-minute London- Edinburgh journey could attract four times the usage, without considering new markets.
Family and friends visits will continue to rise but real growth potential lies in business and foreign visitors. Edinburgh is already the financial capital for the northern half of Britain and the Scottish Parliament, a lively media, creative and housing sector makes it a magnet for a variety of businesses, whose growing use of the first class train service already hints at the potential in this segment. With mobile phone and internet reception and shorter waiting times in security, business travellers find trains much more conducive to productivity.
Add into that the fact that Edinburgh is second only to London as a tourist destination, with six million UK and nine million foreign visitors, nine million of whom come by air, then growth potential for the local economy through HSR becomes obvious. Two hours observing English countryside flashing by could massively increase tourism to Edinburgh and beyond. Little of the foregoing growth is likely if conventional rail and short-haul air are the only means to lure people north.
Taking the new Madrid to Barcelona high-speed line as an example, trains that could also use a conventional UK high-speed line would be capable of 220mph. The Spanish line runs 386 miles - almost exactly the London-Edinburgh distance - with an advertised journey time of two and a half hours, at a speed of 154mph.
The benefits of a tourism boost and a link with London for Scottish business as fast as Manchester or Leeds already enjoy would be only part of the story.
With direct lines to the Chunnel, fast Scotland/continent through journeys become feasible. With Deutsche Bundesbahn already planning London-Cologne/Frankfurt and London-Rotterdam/Amsterdam services from 2013, journey times from here to such destinations comparable with existing London timings are possible.
HSR would link Scotland's Central Belt firmly with the heart of Europe's booming business environment. In this time of economic turbulence, we may envy the prosperity of Scandinavian neighbours but geography plus Chunnel engineering offers rapid access to the heart of our export target market that they would envy. What we need is that fast link of direct access HSR that south-east England already enjoys.
David Berry is an SNP councillor and former East Lothian council leader