Regional Transportation District’s A Line commuter train has hit some bumps since launching in 2016.

In its first year of operation, RTD operators made around 20 mistakes, also known as engineer decertifications, reports CPR. Those mistakes consisted of driving errors like speeding, running red signals or failing to check brakes.

The organization told CPR that some of these mistakes could be attributed to high turnover rates caused by low starting wages at around $16.50 per hour. RTD has since raised wages to between $22 and $25 an hour, which has improved driver quality, said RTD’s deputy assistant general manager of commuter rail, Allen Miller.

“What the numbers basically tell us is that we now have a seasoned operator staff who basically are performing at the levels we expect,” Miller told CPR.