The planned tram overhaul was originally scheduled for April, in sync with the opening of the Regional Rail Link, but has been delayed until at least June while the Andrews government considers its first revamp of public transport timetables.

The plans, leaked to Fairfax Media, reveal that some of the most overcrowded tram routes in Melbourne have been targeted for change and in the case of route 8 between Moreland and Toorak, permanent discontinuation.

Route 8 is statistically one of the city's most overburdened tram routes. In May it recorded load breaches, in which trams are more than 100 per cent full, right across the morning peak and for most of the evening peak.

The overcrowding was worst on trams heading into the city from the northern suburbs. The most recent passenger load survey conducted by Public Transport Victoria revealed patronage levels into the CBD on route 8 had jumped between 11 and 19 per cent in just 12 months.

But route 8 passengers will not be left without a tram service - three other routes will be modified to take its place.

Tram route 55, which runs from West Coburg to the Domain Interchange on St Kilda Road, will be extended through to Toorak.

Tram route 6, which currently runs from Glen Iris to Melbourne University, will be extended to East Coburg.

And tram route 1, which runs from East Coburg to South Melbourne Beach, will instead terminate at Moreland Road in Brunswick.

But users of tram route 19 between North Coburg and Flinders Street Station may have cause to feel aggrieved by the looming changes, with the number of trams that ply the busy route due to be cut.

The service cut will take place in exchange for the route getting a full fleet of high-capacity low-floor trams.

Load breaches remain a problem on route 19, which services the boom suburb of Brunswick and which experienced a 17 per cent jump last year in the number of people using it to travel into the city in the morning peak.

Daniel Bowen, a spokesman for the Public Transport Users Association, said that if route 19 was going to get fewer but larger trams, PTV would need to make sure this did not worsen overcrowding.

He also warned that many people who are used to getting a seat on a tram might have to stand, because low-floor trams have fewer seats.

Public Transport Minister Jacinta Allan said the government was assessing proposed tram network service improvements, "however, no final proposal has yet been provided to government for consideration".

Meanwhile, Yarra Trams is also set to unveil plans for a series of new super stops along St Kilda Road.

Two new platform tram stops are planned between the Domain Interchange and Flinders Street. The number of stops on that stretch of St Kilda Road will be cut from four to two, and the road will change from three lanes to two each way.

Yarra Trams spokesman Simon Murphy said the construction of two new super stops will make the entire tram corridor between Melbourne University and Domain Interchange compliant with disability discrimination laws.

"Platform stops improve passenger and road user safety and network accessibility, which is particularly important on the world's busiest tram corridor," he said.

Yarra Trams has limited its publicity campaign about the mooted changes to posters and leaflets at the affected St Kilda Road stops.

Mr Murphy said: "Yarra Trams and PTV acknowledge that while community feedback is welcome, major changes to the design are not practical due to the space available on the road to meet the needs of tram passengers and other road users."