Contracts were signed this week to pave the way for the introduction of tram-trains between Sheffield and Rotherham - the first of their kind in the UK.
The vehicles, which can run on both Supertram and train tracks, are due to operate on a route between Sheffield city centre and Rotherham Parkgate by the beginning of 2016.
If successful, the £60m Government-financed pilot project could be extended to other cities.
And it also raises the possibility in Sheffield of the dual voltage vehicles being used on heavy rail routes along the Upper Don Valley to Stocksbridge and Deepcar and along the Sheaf Valley to Millhouses and Dore.
Transport Minister Norman Baker was in Sheffield yesterday (Wednesday) to sign the contracts - and to formally open a 130-space park and ride next to Dore and Totley Rail station, which is designed to ease parking congestion on surrounding roads.
Seven vehicles, manufactured by the German group, Vossloh, are being bought for the tram-train experiment, and another three trams are being added to the existing Supertram system to help meet demand at peak times.
Mr Baker said: “Providing better connections between the heart of Sheffield and Rotherham’s city centres and residential areas will help to reinvigorate the local
“It will also encourage people to leave their cars at home.
“Tram-trains are an innovative and high-capacity transport system which have proved very successful in other European cities.
“We will be monitoring the scheme over the course of the next two years and I look forward to seeing if it would be appropriate to replicate it elsewhere in the UK.”
Network Rail will build a new link junction and points between the light rail and heavy rail lines near Meadowhall South. The rail line from Meadowhall South to Rotherham Central Station and Parkgate will be electrified.
New platforms will be built at Meadowhall South and at Rotherham Parkgate, and Rotherham Central Station’s platforms will be extended.
The scheme brings together the Department for Transport, Network Rail, Northern Rail, South Yorkshire Passenger Transport Executive and Stagecoach Supertram.
Margaret Kay, managing director of Stagecoach Supertram, which will operate the vehicles, said: “Tram-train offers us the potential to deliver greener, smarter public transport services to even more people.”