FRUSTRATED commuters could be left waiting until mid-2020 before Queensland Rail's driver shortage is fixed, the company's own modelling reveals.

The forecast has been provided to the Fair Work Commission as QR fights a Rail, Tram and Bus Union challenge to block dozens of driver vacancies being filled by external recruits.

It shows the recovery to full services could blow out beyond earlier predictions, partly due to a controversial new union meal break cutting the time drivers spend behind the controls.

Strict new anti-fatigue rules and an ageing driver workforce are also identified as factors.

"Queensland Rail's modelling demonstrates that current driver demand levels will not be resolved until late 2019," Commissioner Paula Spencer said in a December decision on the ongoing RTBU dispute.

"This is without taking into account any other factors which will result in increased need, such as the introduction of two meal breaks for shifts in excess of six hours, or increased service delivery, which would elongate the time frames until at least mid-2020."

QR's board warned the Government in 2016 the break would "constrain efficient train operations".

But it was adopted in the drivers' new enterprise agreement last year after State Government pressure and could come into effect as soon as May.

Queensland Rail CEO Nick Easy
Queensland Rail CEO Nick Easy

QR now has just 19 extra qualified drivers on its books compared to when hundreds of service cancellations struck the network in October 2016.

It has hired 145 trainee drivers since the problems, of which 51 have finished training.

But 31 drivers either changed roles or left QR in the same period.

The small increase comes despite launching in-house recruitment campaigns for a combined 200 new drivers in November 2015 and following the 2016 rail meltdown.

While QR was unable to fill all the spots internally, it only advertised the jobs to the wider public last August, despite first planning to do so in January 2017.

The move was in line with the findings of the $2.5 million Strachan Inquiry, which took aim at closed-shop recruitment rules by recommending the jobs be thrown open to the public.

While the Government agreed to adopt all recommendations, it initially restricted external job advertisements to ex-QR drivers after input by former Transport Minister Jackie Trad's office.

It took another six months before 50-plus driver vacancies were opened to the wider public.

QR chief executive officer Nick Easy said it was continuing to progress with external recruitment in line with a decision by the Commission last month.