The study was commissioned by the Australasian Railway Association to pressure the federal government to invest more money in public transport.

Association chief executive Bryan Nye says: ''Christmas is only two weeks away and with budgets being stretched, we felt it was timely to highlight the savings that Canberra commuters can achieve by choosing to travel with public transport. For instance, Canberra commuters travelling five kilometres to the CBD in a light car spend on average $4364 per year and those driving a large SUV 25 kilometres into the CBD could be spending $16,591 annually to commute. Leaving their cars at home, commuters travelling five kilometres to the CBD in a light car could save $2429 and commuters travelling 25 kilometres in a large SUV could save $5449 per year.''

To identify savings, the study costed different scenarios.

Under the first, the cost to own and commute with a small car 15 kilometres each way, five days a week, is $7314 a year, based on 231 days of the year. ''Where a Canberra commuter owns a small car, but decides to commute to work with public transport, the annualised cost reduces to $3860,'' it says. ''By leaving their car at home and travelling to work by public transport, a Canberra commuter can save $3454 per annum, or $66 a week.''