Ottawa's transit commission has approved the renaming of the city's entire light rail system — and not just the north-south track — as "The O-Train."

City staff had said in recommending the change that the O-Train had 'stood the test of time' since it was adopted in 2001. the current O-Train line from Bayview to Greenboro becomes the "Trillium Line." With the change,BayviewGreenboro

The east-west line under construction from Blair Road to Tunney's Pasture retains its name as the "Confederation Line."

In addition, the separate lines will be identified by different colours and numbers on transit maps.

North-south line expansion delayed

The commission also heard Wednesday that the planned expansion of the north-south O-Train won't happen for a couple more months, at least.

The city's manager of light rail projects, Richard Holder, told the transit commission the upgraded service won't be ready to roll this month as originally thought because the switch to four trains instead of two, running at shorter intervals on twinned tracks, will require a six-day shutdown.

The shutdown will need to correspond with breaks in the Carleton University calendar to minimize the impact on students.

Holder blamed the delay on a decision last year to upgrade to a centralized traffic control system.

In the weeks leading up to the change, drivers will practice operating the system at night, with no passengers on board. For 45 days after the switch, there will be a parallel OC Transpo bus service running in case there are any problems.