The UK Department for Transport has announced plans to convert the existing 10km Watford-St Albans branch rail line in the county of Hertfordshire into a new tram system.
The proposed system would reduce the St Albans-Watford journey time to 30 minutes, compared to 45 minutes at the moment.
The line could provide a more frequent service using lightweight rail vehicles within the funding used for the existing service, according to the project's consultants Mott MacDonald.
The train frequency is expected to reach three trams per hour under the new system.
The project is subject to a 12-week consultation and, if approved, would enter service in 2011.