A plan to turn Melbourne's busiest tram route into a flagship light railway is struggling to launch as residents and traders along the line fight moves to allocate road space at the expense of parking and car lanes.

Communities in the left-leaning inner suburbs of Brunswick East, Carlton North and St Kilda have gone against type and dug in against Napthine government plans to sacrifice parking spaces for super stops in a bid to create Melbourne's first tram freeway.

The grassroots campaign against the route 96 project scored a big win on Wednesday when Public Transport Minister Terry Mulder announced in Parliament that he had deferred an important part of the project until next year.

Mr Mulder said he had "put on hold" government moves to gain a heritage permit to build a new platform tram stop in Fitzroy Street, until Public Transport Victoria completes a new traffic study. In so doing, Mr Mulder implicitly rejected the findings of a previous study based on just two days of traffic analysis.

The platform stop would go almost directly in front of the driveway of St Kilda Park Primary School where, by its own count, three in four pupils are driven to school. Residents, traders and the school's principal Jennifer McCrabb all told Fairfax Media the new stop would create a dangerous bottleneck.