The main reasons for the poor passenger demand were no express services in peak hour, poor connections with buses and a slow service with trains stopping "all stations", a transport lobby group said.

South-east Queensland’s Petrie to Kippa-Ring train line (Redcliffe Peninsula line) opened in October 2016, amid controversy over train drivers and services.

In that first month, there were only 4709 daily passengers.

In November that dropped to 4645 passengers a day.

By May 2018, the number of passengers using the Petrie to Kippa-Ring rail line had grown to 6451 daily passengers.

However, that was still fewer than one-third of the 20,358 daily passengers predicted when the Petrie to Kippa-Ring rail line was developed in 2010.

Robert Dow of rail travel lobby group Rail Back on Track listed five reasons why passengers were not using the rail line as frequently as predicted.

“I think there is a case – when they recover the timetable – to try to give them some express peak services,” Mr Dow said.

“But they certainly can’t do it at the moment because of the nature of the timetable.”

TransLink said it had added extra express services to the Petrie to Kippa-Ring rail line.

“To reduce travel times for customers on the Redcliffe Peninsula line, Queensland Rail runs Redcliffe Peninsula services express through the inner-northern area from Northgate to Bowen Hills, stopping only at Eagle Junction station,” a TransLink spokesman said.

The Redcliffe Peninsula line services share tracks with Caboolture and Sunshine Coast line services between Petrie and the CBD.

“Our current timetable and stopping patterns are designed to ensure an equitable service frequency at each station along the northern corridor,” the TransLink spokesman said.

Mr Dow said feedback received from passengers was that bus company Hornibrook needed to look at better connections between bus and rail.

“I really think there is a need to look at the feeder bus network to the line. That's important,” he said.

He said the other complaint Rail Back on Track received was “it takes too long”.

“Passengers would like some express services in the peak times,” he said.

“What happens is the trains stop all stations from Kippa-Ring through to Petrie. Then they run all stations from Petrie to Northgate.”

By contrast the Sunshine Coast (Caboolture line trains) ran express from Petrie to Northgate.

“So there is a little bit of express envy there,” he said.

Mr Dow agreed that passengers could get off the Kippa-Ring to Petrie train and wait for an express service from Petrie to Central.

“But the services aren’t always optimal for that,” he said.

Mr Dow said the group was waiting for TransLink to provide 2017 and 2018 travel data so it could check to see if the Shorncliffe line had seen a major patronage bump since October 2016.

“That is patronage that could potentially have gone on the Petrie to Kippa-Ring line,” he said.

“Some of it could be going on to the Shorncliffe line.”

He said some passengers were also going to Dakabin station, north of Petrie, as well as using the faster Sandgate line because they had express services.

Queensland Rail said the state government reduced fares in December 2016 through the Fairer Fares package.

“Fares in the south east are now about 44¢, or 13.5 per cent, lower on average per eligible adult trip than they were before the introduction of Fairer Fares,” the spokesman said.

Queensland Rail said the initial customer demand was based on projected growth in suburbs north of Brisbane, which had not met expectations.