The environmental impacts of a scheme such as Sunderland Metro can be either good or bad, temporary or permanent and can be localised or more wide ranging in effect.
Regional effects are often beneficial and are explained here.
Noise and Vibration Electric Metro trains are quieter than the diesel services they will replace between Pelaw and Sunderland. Despite an increased service frequency, it is calculated that there will be a three decibel decrease in overall noise levels over this section of the route. Predicted noise levels on the new portion of the route are some seven decibels below the qualifying level under the Noise Insulation Regulations. The Sunderland Metro will improve accessibility to public transport, including specific provision for the mobility impaired, allowing an increased number and range of trips to be made. There will be a greater choice of city centre destinations and additional opportunities for interchange with long distance and regional rail services, local bus routes and Newcastle International Airport.