Pressure

Environmental pressures describe pressures from human activities exerted on the environment, including natural resources. "Pressures" here cover underlying or indirect pressures (i.e. human activities themselves and trends and patterns of environmental significance) as well as proximate or direct pressures (i.e. the use of resources and the discharge of pollutants and waste materials). Indicators of environmental pressures are closely related to production and consumption patterns; they often reflect emission or resource use intensities, along with related trends and changes over a given period. They can be used to show progress in decoupling economic activities from related environmental pressures, or in meeting national objectives and international commitments (e.g. emission reduction targets).

Examples of indicators of environmental conditions are:

• concentration of pollutants in environmental media,
• exceedance of critical loads,
• population exposure to certain levels of pollution or
• degraded environmental quality and related effects on health,
• the status of wildlife and ecosystems and of natural resource stocks.

Roadway Lighting

As roadway lighting becomes more sophisticated, so does our understanding of its impacts beyond simply providing visibility. Light pollution and light trespass are being recognized more and more as real effects of excessive or poorly designed exterior lighting. To combat light pollution and light trespass, the following measures have been advocated:

• use of cutoff luminaires so that bare lamps are not visible in roadway lighting fixtures, except from directly beneath them
• designing lighting installations that provide the minimum amount of light needed for safety
• in certain cases, such as in the vicinity of astronomical observatories, use of narrow-spectrum lamps, like low pressure sodium, which can be easily filtered by astronomers
• Roadway Lighting