Revenue service refers to operations where trains carry

• A. Operations where trains perform non-revenue testing only.
• B. Trains carry fare-paying passengers or cargo in service to generate revenue.
• C. Maintenance operations on track.
• D. Emergency drills with passengers.

Answer: (B)

Revenue service is trains operating to generate income by carrying fare-paying passengers or cargo. This distinguishes real passenger or freight movements that earn money from trips done for testing, maintenance, or safety drills, which don’t generate revenue. In practice, a train in revenue service is part of the regular schedule where passengers board and pay fares or freight moves are billed as part of the railway’s operations. Even if passengers happen to be on board during drills or testing, those moves are not considered revenue service because the primary purpose isn’t to provide paid transportation. Maintenance on the track and emergency drills are likewise non-revenue activities since they support operations but don’t produce revenue.