Noisy Roads

Noise is a prominent feature in many urban areas, coming from not just transport but also industries. There are various studies done on the effect occupational and environmental noise exposure on humans, such as that by Stansfield & Matheson (2003), and also the effects of noise exposure on the ecology system (Forman & Alexander, 1998). I’ll try to give a brief summary on these two papers.

Noise as an environmental stressor and nuisance (Stansfield & Matheson, 2003), and is found to cause progressive loss of hearing (under continuous exposure), with an increase in the threshold of hearing sensitivity. Other than auditory effects on health, continuous exposure to noise can give rise to a host of other problems for the human population too.

  • Sleep disturbances
  • Impaired cognitive performances
  • Cardiovascular Diseases
  • Psychological disorders

Meanwhile, Forman & Alexander (1998) highlights how roads impact local ecology with various local hydrological and erosional effects. I will however, focus on the section on ‘Vehicle Disturbance and Road Avoidance‘. The research highlights how different species are affected by vehicle disturbances, and in particular, songbirds who are extremely sensitive to noise levels (for instance, the most sensitive woodland species, the cuckoo, showed a decline of density at 35 decibels.) The article further describes the effect of traffic noise in affecting animals, which not only includes increase in stress levels due to the noise, but other disturbances and changes to the ecosystem which includes the barrier effect of roads which affects the population of various species and their distribution (one example is the genetic structure of small local populations of the common frog in Germany).

Reading this article reminded me of a series of pictures I saw online about wildlife bridges.

I think I’ll need to read more about the benefits of such bridges, but I can see how these bridges can have the potential to remove the barrier effects of roads, and reducing the number of road kills if animals use them. I doubt they will remove the effects of toxic particulates and noise from vehicles though, but this is the least we can do along existing highways that have already been built to minimize further damage to local ecology.


Forman, R. and Alexander, L. (1998). Roads and their major Ecological Effects. The Annual Review of Ecology, Evolution, and Systematics 29:207-231

Stansfeld, S. and Matheson, M. (2003). Noise pollution: non-auditory effects on health. British Medical Bulletin 68: 243-257

The World Geography (2012) Unusual Bridges for Animals — Wildlife Overpasses. [Online] Retrieved from: [Last accessed: 15 March 2015]