Violent is related to Hostile. Hostile is related to Aggressive. Aggressive is related to Attack. Attack is the opposite of Release. 
Traffic is related to Transport. Transport is related to Cargo. Cargo is related to Elevator. Elevator is related to Step. 
Violent <--RelatedTo--> Hostile <--RelatedTo--> Aggressive <--RelatedTo--> Attack <--Antonym--> Release 
Traffic <--RelatedTo--> Transport <--RelatedTo--> Cargo <--RelatedTo--> Elevator <--RelatedTo--> Step 