Train Sim World 3

There are actually 14 scenarios needed for this achievement split up between Class 375, 395, 465 and Class 66. The latter is hidden away and won't appear if you navigate through "To the Trains" and then "Train Depot". You'll find it in "Choose a route", then "Southeastern High Speed" then Scenarios, called Hoo Dares Wins.

Most of the scenarios are pretty straightforward but the Class 66 scenario "Hoo Dares Wins" might be a pain as it's really long and it's pretty easy to fail. This is because the train is horrible to control and the goal markers for each section are really close to a red signal so if you don't pay attention to the speed, the brakes and the signals you'll most likely fail the scenario and have to start over. All I'd say is maintain a slow speed throughout which makes it easier to stop if you find yourself coming up on a red signal unexpectedly.