Editorial

Roadway lighting standards are based almost exclusively on vehicular traffic safety considerations. Benefits of road illumination for drivers include easing of flow of traffic, reduction of night time accidents, visibility of adjacent users, and general way of finding assistance. Road lighting is used specially to highlight hazards despite the glare of headlight beams and reveal signage, in riskier environments, such as urban streets and interchanges where there are exits and entries from local roads.

Energy saving on road lighting is not only good for the environment; it is good for the per capita income of people as well, because the expenditure on energy directly relates to the cost of goods produced. High expenditure on energy decreases profit margins and raises price of goods and services. Therefore reducing the cost of energy through energysaving methodologywill benefit the people directly.

Finding methods and switching to more energy efficient methods to save energy without affecting the final product or outcome can be difficult, but possible. Being professionals, focusing on this aspect is very vital asit will result in tremendous savings in cost of energy. Therefore it is our duty to take measures to save energy in all aspects as it’s a national requirement.

The present Government is highly focused on the Development of National Road Network in Sri Lanka under Infrastructure development, as it plays a key role in the development of the country.  As a result of this, Southern Expressway up to Galle has been already completed and Colombo - Katunayake Expressway is just completed. Therefore the dream of having a developed road network and transport system in Sri Lanka will become a reality in the near future.

During the construction stage of these roads I had the opportunity of providing consultancy services on road lighting systems.

In the road lighting design of Southern Expressway, the average illumination level  in interchange areas was  considered  as 1 cd/m2.

I tried as much as possible to adopt energy saving methodologies and maintenance aspects during the design stage of road lighting systems. On that basis I thought to analyze the consumption of electrical energy of Colombo - Katunayaka Expressway and Southern Expressway as the lighting levels adopted is same i.e, Class “ME3a” as per the CIE classifications  and my report on the detailed analysis is given below.