A system for measuring train operator's environmental performance should be in place by October.
The Office of Rail Regulation plans to introduce indicators for sustainability, including environmental performance, in time for the results to be included in its National Rail Trends document for the end of the year.
It will also evaluate Network Rail's contribution to sustainable development as part of its annual assessment.
The moves were outlined in a new ORR policy that commits it to using its regulatory powers to develop a "more sustainable" railway.
The policy was published after the ORR had 29 responses to a consultation document released in October last year. They included most passenger train operators, freight operators, Network Rail, passenger groups and leasing companies.
The document proposed a system of financial penalties and incentives for operators to meet environmental targets. These are not included in the final policy, although it does say their "potential introduction" should be reviewed in the "longer term".
The ORR said it "recognised the need for caution" because environmental charges might increase the cost of rail and push people on to other, less environmentally friendly, modes of transport.
In the meantime, the ORR will develop about six key performance indicators. It expects operators to co-operate in gathering the information, but reserves the right to force them to take part if necessary.
Chief executive Bill Emery said the "consistency" of responses had allowed the ORR to publish final conclusions without the need for a draft document.
The ORR will now review information collected by the Association of Train Operating Companies and the Rail Safety and Standards Board, and consider which indicators to use.