2.5m fewer Translink journeys this year
Research carried out for Translink has found 2.5m fewer journeys were made on the company's services this year.
The independent research showed that overall passenger numbers for NI Railways, Ulsterbus and Metro fell between 2009 and 2010.
However, it also showed the number of Ulsterbus travellers satisfied with the service was at an all-time high since evaluations began in 1994.
Customer satisfaction with NI Railways was up by over six percent.
Belfast metro's services suffered a slight decrease in satisfaction levels of just over one per cent.
Ryan Simpson, Senior Consumer Affairs Officer at the Consumer Council, welcomed the high overall satisfaction levels amongst Translink passengers, but said he was "concerned" by the drop in passenger numbers and warned that the company must do more to reverse the decline.
"The challenge still remains for Translink to present the public transport system as a viable alternative to the car by offering a range of cost-effective ticket options, which the public perceive to be value-for-money, and which will increase passenger numbers," he said.
Mr Simpson said a wider adoption of cash-less ticket options such as Smartlink and iLinkcards could improve value-for-money for customers.
"Earlier this year the Consumer Council called on Translink to develop a plan to increase the uptake of cash-less ticket options and whilst Translink have introduced a number of promotions, these have only resulted in a modest increase in uptake," he said.
Focusing on the positive findings within the research, Translink's Ciaran Rogan said it was "a great set of results".
"Both NI Railways and Ulsterbus have met on time targets and our customers tell us they recognise the good work done in terms of value for money and staff helpfulness," he added.
"These results show why more car drivers are choosing the bus and train; avoiding expensive fuel and parking charges. We will continue to invest in and improve our services to give hassle-free, great value choices."
Translink's three companies are assessed twice a year with reference to the standards set out in the passenger's charter.