Train Sim World 2

Spawn walking at Victoria. Better at Victoria as services end automatically, you don't have to lock doors again.

Take over a service, doesn't matter which as they all give 500pts

Save just before passenger loading circle completes

Quit to main menu and then resume saved game

Each time you replay the saved game, you get 500 points. If you are on a series X, main menu to game to going back to main menu is less than 25 seconds so essentially you'll be getting 1000 points every minute. Roughly 20 minutes per level up.

Yes it's boring and a grind, but it's much quicker than actually playing services.

Just remember to quit to main menu every time

This works on all levelling up achievements, but some you have to lock the doors to finish, some you don't.

Edit: achievement unlocks upon reaching level 20, not level 21 like some DLCs

1. London Commuter > Explore > Explore on Foot > Brighton (Time 10:00)
2. Go over to Platform 3 where a Class 377 is waiting.
3. Make a save before taking over from the driver.
4. Take over from the driver.
5. Once you have taken over from the driver, you will get 5000AP
6. Return to main menu immediately, you will keep the 5000AP
7. Resume Savegame and repeat this over and over, until you are level 20.