3.3 Impact of noise and vibration on health

This benefit covers land transport noise and vibration that impacts on human health. Noise and vibration can come from construction, operation, maintenance and use of land transport infrastructure.

Long-term exposure to transport noise and vibration can have significant impacts on human health, primarily related to sleep disruption and stress, and the resulting health impacts. Other impacts may include speech interference, cognitive impacts, and psychological and behavioural impacts. There is no evidence of permanent hearing loss from road traffic noise for people living nearby roads.

Humans are very sensitive to vibration, and the effects of vibration on human health and wellbeing are similar to noise. Vibration can cause sleep disruption, stress and annoyance. Vibration may be ground-borne or arise from sound that causes secondary vibration (eg window rattles). Both forms of traffic-induced vibration may produce resonance, which is perceived as sound or as a body vibration.

The primary road traffic noise source arises from tyres on the road surface during vehicle movement. Other noise sources include engine and transmission vibration, exhaust systems, bodywork and load rattle, air brakes and friction brakes, horns, doors slamming, car audio systems, and aerodynamic noise. 

Current quantitative measures focus on noise emitted during transport infrastructure use, including road traffic noise. Monetisation calculations consider the cost of property and the number of dwellings to determine a standard cost of noise per decibel as a proxy for comfort and wellbeing, with ongoing work focusing on developing measurement of health impacts. Vibration is currently a qualitative measure.

In larger investments, this benefit is likely to be a co-benefit, for example when noise barriers are part of a larger construction project, a low-noise road surface is selected, or a route is selected that reduces community exposure to noise.

The people impacted by this benefit are residents, workers, or visitors in areas affected by transport noise or vibration. Impacts on people’s activities may be cognitive (eg schools, workplaces), cultural (eg religious services, marae) or amenity (eg parks and recreational areas).