The American Iron and Steel Institute (AISI) estimates that approximately 185 million utility poles are in service in North America, and most of them are made from wood. When utility poles need to be replaced or a new distribution line set up, utility managers consider factors such as cost and reliability. But increasingly they are also considering the impact of the material on the environment and reviewing their options. By Mark Thimons, director, construction sustainability, Steel Market Development Institute, a business unit of the American Iron & Steel Institute