Transport bosses are looking at ways to develop the potential of the Borders Railway as the line marks three years since it opened to passengers.
The 30-mile route between Edinburgh and Tweedbank was the longest new line built in the UK for over a century when it was opened by the Queen in September 2015.
ScotRail said more than four million journeys have been made on the line with year-on-year increases in passengers, with a further 5.8% growth over the last year.
Campaigners would like to see the line extended and Transport Secretary Michael Matheson said he will continue to look at ways to develop the potential of the route.
He said: “The Borders Railway has been a phenomenal success as it continues to grow in both popularity and bringing benefits to the local economy.
“The ongoing increase in passenger numbers since it opened three years ago demonstrates it is acting as a catalyst for investment while opening up employment, leisure and education opportunities for communities along its length.
“We continue to look at ways to develop the potential of the line and the recommendations from the Borders Transport Corridors Study will, in turn, feed into the ongoing Strategic Transport Projects Review.”
Alex Hynes, ScotRail Alliance managing director, said: “The Borders Railway continues to provide a strong and reliable transport connection, benefiting employment, leisure, tourism and business.
“We are committed to building the best railway Scotland has ever had and this line is helping us to deliver that, transforming the way people across Midlothian and the Borders travel.
“Reaching the milestone figure of more than four million passenger journeys demonstrates the success of what was an ambitious project, and I look forward to its continued growth.”