Road ecology

[2] Road ecology is practiced as a field of inquiry by a variety of ecologists, biologists, hydrologists, engineers, and other scientists.

[16] Carbon dioxide is non-toxic to humans but is a major greenhouse gas and motor vehicle emissions are an important contributor to the growth of CO2 concentrations in the atmosphere and therefore to global warming.

[19][needs update] Urban runoff from roads and other impervious surfaces is a major source of water pollution.

[20] Rainwater and snowmelt running off of roads tends to pick up gasoline, motor oil, heavy metals, trash and other pollutants.

Road runoff is a major source of nickel, copper, zinc, cadmium, lead and polycyclic aromatic hydrocarbons (PAHs), which are created as combustion byproducts of gasoline and other fossil fuels.

[22] Road salts (primarily chlorides of sodium, calcium or magnesium) can be toxic to sensitive plants and animals.

[24] De-icing chemicals, salt, chlorides and the nutrients brought by particulate pollution such as nitrogen (N) and phosphorus (P) can trigger trophic cascades in adjacent waterways.

[27] Motor vehicle traffic on roads will generate noise, in a wide range of frequencies which can affect both humans and animals.

Birds may spend an increasing amount of time using visual scanning to spot predators as a result of auditory cues and alarm signals from other species being masked by noise pollution.

A decreased amount of time spent feeding may lower the mean body weight of birds living near roads, which directly affects their survival rates in a negative fashion.

[39] This effect can lower rates of feeding, which leads to a reduction in nestling body size and chance of post-fledgling survival.

Noise health effects can be expected in such locations from road systems used by large numbers of motor vehicles.

A new road scheme planned in Shropshire, UK promises to reduce traffic noise in Shrewsbury town centre.

In areas where most native forest has been cleared, roads can make it easier to move crops to market and import fertilizers.

[41][needs update] Roads can act as barriers or filters to animal movement and lead to habitat fragmentation.

[43] Whether or not this effect is observed depends greatly on the size and mobility of the species in question and the spatial scale at which the fragmentation occurs.

[49] Road implantation may also lead birds to avoid certain sites, as they are seen as being less habitable (because of increases in noise and chemical pollution).

Certain bird populations may then become confined into smaller habitable sites, leading to an increase in possibility of extinction caused by illness or habitat perturbation.

[51] Awareness needs to be spread among drivers particularly those driving on forest road on maintaining speed limits and being vigilant.

Underpasses were seen to lower mortality rates and increase local species ability to adapt to a habitat along a major road.