ScotRail has began testing its new trains on an electrified route for the first time.
The rail operator says its new fleet of Class 385 electric trains will offer faster journeys, more seats and better services for customers travelling between Scotland's two biggest cities.
One of the new trains, which have still to be fitted with interiors, successfully travelled between Edinburgh and Linlithgow in West Lothian on Wednesday.
It was the first time an electric train had travelled on any section of the route.
Full testing of the new trains will begin when the final safety checks on the infrastructure have been carried out and remainder of the route is complete.
The trains are due to enter passenger service over the next few months.
ScotRail Alliance programmes and transformation director Ian McConnell said the trial was a "hugely important step" towards completing the electrification of the line.
He said: "Having a train run on the route is one of the final phases of the electrification process.
"That it has gone so well tells us that we are almost ready to begin the next stage, which is to start fully testing the new trains themselves.
"We are building the best railway that Scotland has ever had. When we replace the diesel trains with the brand new, state of the art, electric fleet we will deliver enormous benefits to our customers.
"Cleaner, greener travel with more seats and faster journeys will completely transform travel between our two biggest cities."
Hitachi Rail Europe programme manager Andy Radford, said: "It's positive so see that progress is being made on Edinburgh to Glasgow electrification.
"We're hopeful that we'll be given permission to start full testing soon so we can guarantee the trains can run for passengers safely.
"We've now got trains at our factory in Newton Aycliffe ready to travel to Scotland as soon as they can run on new electric power line."