Although Translink's Autumn 2012 Passenger Charter Monitoring Results report very high levels of punctuality and reliability, customer perception of timings continue to be lower than reported, the watchdog said.

Translink's Ciarán Rogan described the Metro services results as disappointing.

He added that even though the services are running on time, customers in Belfast continue to be frustrated with disruption in the city centre - they want faster journeys.

"This is why bus priority (actually bus passengers' priority!) is so important and while construction has caused some short term frustration, the benefits will be huge.

"We work closely with our colleagues in DRD Roads Service and have welcomed the introduction of the new bus lanes in the city. These are delivering real improvements for the tens of thousands of passengers using Metro services every day. More space for buses means faster journeys and better services for bus customers; this adds up to less traffic and a better city for everyone."

Results for the Translink Contact Centre have also fallen again and remain below target, the Consumer Council revealed.

Antoinette McKeown, Chief Executive with the council, said: "Accessing information is crucial for passengers, especially when services are cancelled or delayed.

"The Consumer Council has consistently raised our concerns with Translink on the importance of quality information and now want to see improved performance for consumers in this vital area."

She continued: "Metro has recorded its third consecutive fall in customer ratings since Spring 2011."

The consumer chief said this is "a genuine concern" given the range of improvements and Government investment in public transport delivered over the period.

"Translink needs to address this continuing fall in customer satisfaction as a top priority and we will be seeking details on the clear action plans Translink will be putting into place."

Ms McKeown added that the Consumer Council continues to work with Translink and the Department for Regional Development to review and revise their Passenger Charter in line with customer feedback.

Meanwhile, NI Railways and Ulsterbus have achieved the highest ratings ever for the 2012 autumn period.

Mr Rogan said that customers like the new high quality Goldline coaches, free Wi-Fi and the real time 'Journey Check' facility for train travel.

"We have also been working very hard to improve cleanliness and our customers are recognising this."

He added: "The results of this research are always helpful to identify what our customers want and what we need to improve to keep getting it right."