The city has a potential fix in place that could get the Metro Line running at full speed, but it won't be ready in time to meet the latest deadline for Aug 31.

"We're very close," city manager Linda Cochrane told council's executive committee on Tuesday.

The city hoped to have the trains running at full 50 km/h speed by the end of the month, but the software fix wasn't installed until Saturday. The city and a third-party auditor, Rail Safety Consulting (RSC), are testing the results to see if the major safety and reliability concerns have been resolved.

"We have good positive results from preliminary testing," Cochrane said.

Currently, the line is running at full speed, except at intersections. The patch is intended to fix three major issues:

A long wait between when the crossing arms go down and the train actually crosses the intersection

The crossing arms go down too late, causing the train to cross the intersection before the arms are fully down

The intermittent loss of communication between the trains and the signalling system

The problems all stem from the signalling software provided by Thales, an electronic system company, and have held up the full operation of the line since 2014.

Once those issues are resolved, the city, Thales, and the contractor and RSC will work toward running the trains at full frequency, every two-and-a-half minutes.

Cochrane could not give a timeline for the full implementation of the Metro Line, except to say it's expected some time in 2017 "if all goes well."

City not setting any more deadlines

Councillors expressed their continued frustration that the line is still not operational.

"I've got concerns this is never going to work right," said Coun. Michael Oshry. He asked if the city will at some point have to consider throwing out Thales' signalling system and start over.

But Cochrane said, based on what they've seen so far, the best solution is to stay the course. She believes the technical fixes will come, even if they are long overdue.

Cochrane said she doesn't want to give any more firm deadlines because the project has so often failed to meet them.

"I'd hate another missed deadline to be the next big story," she said, given the work by city staff to ensure the project runs safely and reliably.

She promised to return with another update to council when the trains are ready to run at full speed.

In the meantime, the city has managed to improve traffic wait times along the line. At Princess Elizabeth and 106th Street, the wait has been reduced to one-and-a-half minutes from three minutes, and fifteen seconds.

Pedestrian movement has also improved by 25 per cent.