ScotRail has completed a test of an electric train along the full route between Edinburgh and Glasgow for the first time.
It comes after a successful trial between Edinburgh and Linlithgow in West Lothian in the early hours of October 18.
One of the new Hitachi Class 385 electric trains has now travelled between Edinburgh Waverley and Glasgow Queen Street for the first time, making the trip at 12.30am on Wednesday.
Full testing of the trains and the infrastructure along the route will continue for several weeks.
It is hoped the new trains will deliver faster journeys, more seats and better services for customers travelling between Edinburgh and Glasgow, and will then be rolled out to other routes in the central belt.
The trains are due to enter passenger service over the next few months.
ScotRail Alliance Programmes and transformation director Ian McConnell said: "Having a train run successfully along the full route shows real progress.
"We are building the best railway that Scotland has ever had. When our brand new, state of the art, electric fleet enter service, customers will reap immense benefits."