Before revision: Worldwide perspective 250px| A noise barrier in Melbourne, AustraliaEven without regulation, there are strong individual economic pressures for quieter vehicles, because owners and employers see quieter vehicles as more luxurious and less stressful.
After revision: Worldwide perspective 250px| A noise barrier in Melbourne, AustraliaNoise barrier on the A16 near Dordrecht, NetherlandsEven without regulation, there are strong individual economic pressures for quieter vehicles, because owners and employers see quieter vehicles as more luxurious and less stressful.