ELIGIBILITY for concession fares on public transport should be drastically restricted or available only during off-peak times, to improve the profitability of trains, trams and buses, according to an influential transport lobby group - whose members include the Brumby government.

In a report to be launched today, Meeting the Funding Challenges of Public Transport, advocacy group the Tourism and Transport Forum proposes six ways to increase revenue and cut the costs of running public transport.

The report concludes that the ''most prospective'' way to help public transport operators raise revenue is to cut the number of people eligible for concession fares.

This would make public transport more financially sustainable, by helping pay for improvements to services, according to the group, whose members include transport operators across Australia.