Melbourne needs 25 new trams every year – more than double the current intake – but trams are yet to feature in the political race to pledge multibillion-dollar road and rail projects.

Trams have been the forgotten election issue, according to an exclusive analysis by a respected rail think-tank calling for the number of new trams to be turbocharged.

About $300-400 million must be spent on new trams every year to allow for a fleet of around 640 low floor trams by 2034, the Rail Futures Institute has said.

This growth of the fleet would help ease overcrowding and prepare for a spike in patronage.

By 2020, 90 new E-Class trams will have been delivered to the network since 2013, an average of about 12 a year. (About 70 are currently in service.)