The first images of what the new Croxley Rail Link stations will look like emerged this week as planning applications for the huge project were submitted.
Pictures released in the application show the line will go over a viaduct over the roundabout with Rickmansworth Road and Watford Road.
An artist's impression of what the viaduct over Rickmansworth Road and Watford Road will look like.
It will then connect with an elevated platform at the new station in Ascot Road.
The line will next go along disused track to connect with another new station in Vicarage Road.
The computer-generated graphics give the first glimpse of what the stations’ design will look like.
The scheme will see the Metropolitan Line routed from Croxley Station, to a new one in Ascot Road called Cassiobridge, then another new station in Vicarage Road called Watford Vicarage Road before connecting with Watford High Street Station and then terminating at Watford Junction.
As a result of the scheme Watford Metropolitan Station will close to passengers and be used as siding.
A first look at the two new stations, viaduct and electricity substation that will make up the Croxley Rail Link have been submitted to Watford Borough Council.
Although the scheme already has permission to proceed under its Transport and Works Act Order, the detailed designs must be signed off by the town’s development control committee.
The viaduct, which also passes through Croxley Green, must also be given permission by Three Rivers District Council.
The plans, which include Cassiobridge Station and Watford Vicarage Road Station, will be considered at a meeting on April 3.
Trees and bushes have sprung up along the disused line and will be cleared by contractors. Geological investigations and surveys of possible electricity cables, water pipes, sewers and communications cabling are being carried out.
Elected Mayor of Watford Dorothy Thornhill said: “It is good news that planning applications are about to be made and preparatory work has started as the Croxley Rail Link is a key transport improvement for the town.”
Hertfordshire County Council and London Underground now expect that trains will be running on the new link in 2017, later than originally planned.
Mayor Thornhill added: “The delay to 2017 does not affect our big projects as we always knew that a complicated scheme like this may have some slippage.”
Terry Douris, cabinet member for highways, said: “We're making good progress with the on-site investigations and are gathering a lot of important information we need to finalise the engineering designs and timetable.
“We’ve been working closely with London Underground to ensure our construction programme is co-ordinated with its works to modernise the existing sections of the Metropolitan Line.
“As a result we’ve had to make some changes to the project timetable.
“While this means it will take a little longer to get the new rail link up and running, it does give us tighter control of costs and greater certainty we can complete our elements of the scheme on time.”