Car 'first choice for transport'
More than £1 billion was spent on buses and trains in Northern Ireland during the first decade of this century but most people still preferred the car, the audit office said.
Morning rush hour bus speeds on main routes in Belfast fell by a fifth due to time spent at kerbsides picking up increased passenger numbers.
Belfast's rapid transit system, planned for March 2012, was delayed until autumn 2017 because of tough economic circumstances.
The number of rail passenger journeys doubled to 13 million with the introduction of new rolling stock but bus numbers increased by just 1.5% to 67 million, according to comptroller and auditor general Kieran Donnelly.
Mr Donnelly said: "Public transport has enjoyed substantial investment of £1.1 billion in the first decade of this century.
"However, passenger numbers have not increased significantly and the car remains the dominant mode of transport.
"DRD needs to do more to attract people onto public transport and make it their choice mode of travel."
Mr Donnelly published his report on the effectiveness of public transport in Northern Ireland.
Auditors acknowledged that a substantial investment of £1.1 billion vastly improved the public transport infrastructure and transformed rail travel with passenger journeys doubling to 13.2 million.
In contrast, total bus passenger journeys increased by just 1.5% (to 66.9 million).
The report said: "Despite a strategic commitment that public transport should service a higher proportion of journeys by providing an alternative to the private car, there has been no modal shift."
Key findings included:
:: Rush hour morning bus speeds in Belfast have fallen by a fifth since 2001, largely due to increased passenger numbers which meant buses spending longer at kerbsides;
:: Changing economic circumstances delayed introduction of a rapid transit system until autumn 2017;
:: Public transport's share of work-related trips decreased slightly and t he number of car parking spaces in the city centre increased with the opening of new shopping centres.
The report said: "In the first decade of this century, Northern Ireland's car dominance has strengthened."
It added: "Attracting greater numbers of car users to public transport and maintaining acceptable levels of public transport passengers will require a much better understanding of demand in terms of the attitudes and behaviour of the potential passengers.
"More recognition needs to be given to modal shift and how to achieve it.
"We recommend that the department sets consistent and coherent targets over a defined period for modal shift which state clearly what its priorities are in order to enable more rigorous and objective measurement of its progress in meeting them."
Ulsterbus provided a higher level of service than comparable regions in Great Britain while Metro service levels compared less favourably than similar city regions although fares were competitive, auditors said.
Passengers enjoyed relatively high levels of comfort, however, Metro customers were less satisfied than those in Great Britain.
Rail services operated as efficiently. F ares were generally cheaper but journeys remained relatively slow.
Rail customer satisfaction ratings compared very favourably to their UK counterparts.
DRD has said the allocation of funding reflects the maintenance needs of the road and rail network and significant investment in the main road network to build connectivity and address the legacy of under-investment.
The audit office said: "We found a paucity of professional public transport skills available within DRD.
"This limits their ability to influence public transport services and effectively hold Northern Ireland Transport Holding Company/Translink to account."