I've had a delve into this....
The first thing to note is that a restored railway/tramway would run on the same corridor as the Bristol & Bath Cyclepath/Walkway, just as the proposed Bus Rapid Transit route (which sparked bitter opposition) between Bristol city centre-Emerson's Green would (links below.)
http://www.bristolbathrailwaypath.org.uk/home.shtmlhttp://www.bristolcyclingcampaign.org.uk/campaign/bristolbathpath/map.pdfThe link below does not inspire me to conclude that there would be much less opposition to a restored railway/tramway than there was/is to Bus Rapid Transit.
http://www.bristolcyclingcampaign.org.uk/campaign/bristolbathpath/Mark Bradshaw, the councillor responsible for transport at Bristol City Council, recently dropped plans for Bus Rapid Transit along the Bristol & Bath Cyclepath/Walkway, essentially because he didnt think the lanes and the gantries needed for the dedicated bus route would fit (link below.)
http://thisisbristol.co.uk/displayNode.jsp?nodeId=145365&command=displayContent&sourceNode=145191&contentPK=20765914&folderPk=83726&pNodeId=144922Cynics would argue that his comments were driven by a need to rule out the scheme on the day a delegation from Bristol headed to Birmingham to lobby for cycling city status and ^20 million in investment (Bristol later gained cycling city status -
http://www.firstgreatwestern.info/coffeeshop/index.php?topic=1860.msg23282#msg23282) but the situation at certain points on the route does back up his claims (example link below.)
http://bristol-rail.co.uk/wiki/index.php?title=Kingswood_JunctionAnother potential obstacle is that part of the former trackbed between Mangotsfield and Siston Common has disappeared (link below.)
http://bristol-rail.co.uk/wiki/index.php?title=Siston_HillQuote from Wikipedia (link below) :
http://en.wikipedia.org/wiki/Bristol_%26_Bath_Railway_PathFrom 1999 to July 2001, South Gloucester county council built a new section of the A4174 Avon ring road, along part of the railway path. Whilst the work was being under taken the path was diverted away from the route of the old railway line. A new section of path was added around the ring road which increases the length of the railway path by 200 yards. The new section includes two bridges, several tight corners, a hill described by SGC as a 'barely perceptible gradient' that puts cyclists into two blind bends at about 20mph, and two cattle grids.
Possibly not ideal as a restored railway/tramway route...
Further on, there is the question of how to incorporate the Avon Valley Railway (link below.)
http://www.avonvalleyrailway.org/However, if the obstacles and opposition were to be overcome, a theoretical tramway could extend from the Newbridge Park & Ride terminus of the line proposed by Trams for Bath (links below.)
http://www.bathtram.org/tfb/tMapfrm.htmhttp://www.bathtram.org/tfb/tR03.htmPossible route :
Bath Spa (main line rail/bus interchange)
Newbridge (Park & Ride)
Kelston
Saltford
Bitton
Oldland Common
Warmley
Siston Common
Mangotsfield
Staple Hill East
Staple Hill
Fishponds
Ridgeway Road
Devon Road
Lawrence Hill (main line rail/bus interchange)
Bristol City Centre
I wouldnt bank on it ever happening, though.....