Transcript: What’s the difference between a traffic filter and a bus gate? Answer: More people can drive through a traffic filter! Traffic filters: Many different groups can drive through, including buses, taxis, emergency vehicles, vans/HGVs, and some cars. There will be 100 free passes for Oxford residents, 25 free passes for Oxfordshire residents, and 18 types of exemptions. Bus gates: only buses, taxis, and emergency vehicles can drive through. There have been 5 in Oxford’s city centre since 1999.