This achievement requires the player to deliver three consecutive jobs of heavy cargo on time, without damage, and without getting fines during the drive.
Save a lot, and if you do get a fine, reload your last save. You can still get the achievement that way. Don't forget to turn on your lights during rain, that's why I got a fine and had to reload.
In the job screen you can add filters. If you choose the filter on the weight you'll probably get the heavy cargo jobs first. Remember, three in a row, so don't take other jobs in between them, only heavy cargo ones. I suggest going for jobs with a low distance. The quicker it's over, the smaller the chance to get a fine.