A leading Belfast architect today proposed a radical solution to the city's traffic congestion - the construction of an underground railway.
Arthur Acheson said such a project should be part of a transformation of the city's image and infrastructure which is gathering momentum.
He said that with some experts predicting that the population of Belfast would treble to a million over the next 15 years, an imaginative and cohesive plan was required - and fast.
Mr Acheson's vision includes a Metro system which would by 2020 link new developments such as Titanic Quarter and Laganside with universities, hospitals, schools, and bus and rail stations.
The scheme has not been costed, but its author believes it could be public sector led and built with private sector investment negotiated under existing "planning gain" legislation.
"As was shown last Wednesday evening, one road accident paralyses a quarter of our city, while two accidents close half the place - and this is a situation which is getting worse," he said.
Mr Acheson, a partner in the Boyd Partnership at Ravenhill Road and himself a qualified city planner, said there was no time to waste.
"Belfast has a brief opportunity to draw up an integrated plan which will co-ordinate the £5bn worth of private sector investment which has already been committed for the next 10 years," he said.
"The Belfast Metropolitan Area Plan inquiry continues apace, but this is a plan which is already 10 years out of date.
"The new BMAP plan is not due until at least 2009 and it will run for just six years until 2015, or perhaps, if it is stretched, to 2018.
"Even if the new plan is adopted, it is only one consideration among a multiplicity of planning policy statements, many of which are loosely worded, plagued by precedents and actually contradict each other or the plan."
Mr Acheson said transport was a priority in creating a new-look and sustainable environment for Belfast.
" Belfast needs an underground Metro system which will provide fast and pleasant transport around the city and link in with the new access to be provided by E-way to Titanic Quarter and beyond.
"Early agreement on such a scheme would enable many large development proposals to factor in their own underground stations and linkage - that's planning gain."
Mr Acheson added: "If we are to delay we risk spending more time on outdated thinking and further entrenchment into unsustainable infrastructure.
"We would miss this opportunity to rediscover in the 21st century Belfast's 'lost art' of city building.
"After all, in the 19th century William Dargan, the great Irish engineer, had the vision to build Dargan's Island, now Queen's Island, 800 miles of Irish railways and the Ulster Canal - all with no Google Earth on his laptop."