Phase 1 of the Highland main line improvement project was delivered back in 2012, and that increased services from nine to 11 trains. The main part of that project, phase 2, was completed in March 2019, at a cost of £57 million. That included upgrades at Aviemore and Pitlochry stations for signalling, along with the extension of the passing loop at Aviemore and the reconfiguration and extension of the platforms at Pitlochry, which enabled the simultaneous arrival of trains at both those stations.

There are currently no active enhancement projects on the Highland main line, but officials at Transport Scotland continue to revise its programmes of work against the priorities in the context of the available funding.