By Martin Cassidy
BBC NI environment correspondent
Belfast does not have the population to support a light rail system
Belfast cannot justify the cost of a light rail system, like the Luas in Dublin, to ease traffic congestion, commuters are being told.
Instead, a report by the Department for Regional Development, said a high class bus-based network could cut commuting times while costing significantly less.
Regional Development Minister Conor Murphy said a new bus network for Belfast was affordable and realistic.
Northern Ireland taxpayers now look set to invest more than £100m.
However, it will not be in the light rail system which has proved so popular in Dublin.
Instead of the £590m needed to establish a light rail network, the consultants say a high quality bus-based system with vehicles carrying 120 passengers, could be built for close to a quarter of the cost at £147m.
Belfast, it seems, simply does not have the density of population to justify a railway network in the city.
The report suggests that running a Luas style service in Belfast would cost taxpayers £6.78m annually, while investing in the large flexi-buses which many European cities have opted for would cost £1.44m to run each year.
The study found that bus-based rapid transit produces positive economic results, but light rail does not.
This is because the likely numbers of passengers do not warrant the extra cost of light rail.
The report by Atkins & KPMG, however, said there would be the option of migrating to light rail in the future should the demand increase.
Mr Murphy says it was a service that should be segregated from other traffic as much as possible with new vehicle designs that enhance the journey and reflect Belfast as a 21st century city.
Three pilot routes are suggested, running from Dundonald in the east to the city centre, to one serving the development in Titanic Quarter and onwards to Queen's University and the City Hospital and thirdly one into the west from the city centre to the Royal Victoria Hospital and beyond into west Belfast.
Officials are stressing that the three routes represent a start. Further lines could be added in the future.
At peak times the high-tech buses would carry just over 3,000 commuters per hour.
The Department for Regional Development believes commuters will be attracted by a service where buses depart every five minutes and offer a fast, comfortable and inexpensive journey to and from the centre of town.
The minister is stressing that no decision has yet been made on which high speed transit network he will recommend to his ministerial colleagues.
The publication of this report though suggests the executive is likely to favour the bus-based network.
Stakeholders such as Translink, which is building up its Metro service, now have six weeks to comment on the report.