The car park was reduced to about 90 spaces from 236 spaces in order to encourage commuters to walk, cycle or catch the bus to the station.

But public transport advocates say the changes have highlighted the need for more frequent and better connected bus services to Epping station.

Transport department spokesman David Stockman said it was expected that parking demand would decrease once the new station at South Morang opened in April. "The new South Morang station will have parking capacity for approximately 450 cars, [making it] one of the largest on the network," he said.

Mr Stockman said overall the project would provide a net gain of 40 per cent more parking on the Epping line, with extra spaces at the Keon Park and Lalor stations.

Mernda and District Residents Association secretary Matthew Ferrantino said while the problem was temporary, it forced residents to travel to Lalor or Thomastown or arrive at Epping before 6am to get a park.

Mr Ferrantino said the situation would further magnify traffic issues along Plenty Road.

"The reduction in the 562 bus services, providing a link to the route 86 tram, has also put further strain on the transport needs of Mernda and Doreen residents," he said.

Public Transport Users Association spokesman Daniel Bowen said the situation showed how poor bus services in the surrounding suburbs were.

"Frequent bus services meeting every train can be more cost-effective than extra parking, and would allow people to use the trains all day – not just if they're early enough to get a park," he said.