“The GCL will effectively extend the Philadelphia-Camden metropolitan area,” said John T. Hanson, the DRPA's CEO. The environmental study included feedback from hundreds of community members at two public hearings last fall and during a public comment period that ended in December. Some people questioned the need for the line, citing disturbances it may create. Some favored service powered by electricity rather than the current plan for diesel power. "Right now technology would allow for electric cars, but this would require more risk and expense to add either a third rail for electrification or an overheard … structure," Hanson said. "One of the most important things for people to remember is that as tools, methods and technology improve, there likely will be revisions to the plan to take advantage of advances," he added.