PUZZLE 079 Ride the Rails

There are four railways running parallel to each other, and each has four stations.
It costs £2 to travel through unlimited stations on one railway line.
It costs £1 per station to travel on a bus that links vertically adjacent stations on different railway lines.
What is the cheapest possible route from the station at the bottom-left, taking in all three of the red stations along the way?
There is no other possible mode of transport.

Hint 1

First, find the shortest route through all three red stations.

Hint 2

Continuing on from hint one...
The shortest route passes through eight stations, not including the departure station.

Hint 3

Continuing on from hint two...
The first stop is the station at the bottom-right, so take the direct route there.

Super Hint

Continuing on from hint three...
You can just pass through the red stations; there is no need to stop at them.
Be careful when you are calculating the fare.

Answer for 'Ride the Rails'

The answer is '7'.