Here is the full list of all 12 Transport Giant achievements.
Finished Europe campaign
Finished Australia campaign
Played for at least 10 hours
Finished USA campaign
Exceed demolition costs of 1,000,000
Earn at least 100,000,000
Played for at least 1 hour
Possessed 25 vehicles at a time
Possessed 10 vehicles at a time
Play for at least 50 hours
Play for at least 75 hours
Play for at least 100 hours