A petition has been set up calling for the council to consider re-opening a long-lost railway line which used to circle the city.
The Edinburgh Suburban and Southside Junction Railway was closed to passenger trains in 1962.
There was renewed interest in opening the line again towards the end of 2018, following an article on the New Stateman's City Metric site.
Edinburgh council has launched a consultation on a major shake-up of public transport in Edinburgh, but reopening the Sub has never seriously been considered.
But a new petition aims to get 500 signatures calling for a full feasibility study into the route.
It argues that much of the infrastructure is already used for freight trains and the Borders Railway line. The Sub line would be a useful addition to the city's public transport and would help to tackle climate change, it says.
The Change.org petition says: "The Edinbrugh South Sub provides an existing cross city route avoiding the city centre for some journeys, as the route passes several shopping, education, healthcare and residential destinations.
"This double track route is currently only open for freight and the occasional empty passenger services.
"The line was opened in 1884, with passenger services withdrawn in 1962 but is still maintained to this day by Network Rail Scotland."
The rail line could link to the existing tram network, or use "train trains" to run on both.
It says: "The fact that this line passes through one of only 6 Scottish UK Parliament Constituencies without a railway stations indicates something isn't right, especially as this is an urban not island / rural constituencies.
"It means for Edinburgh South residents all journeys by rail are extended with bus connections to the city centre and less convenient than using a car."
The council's City Mobility Plan 2030 consultation launched earlier this year.
