Many older tunnels today are not used to their full potential or are not used at all due to their structural condition. These tunnels can be widened to accommodate larger freight trains, trucks, light rail or to increase traffic capacity, and in the case of leaking or deteriorated tunnels can be fully rehabilitated. Dr. Sauer & Partners' can develop a solution to suit the rehabilitation project, this will include the design of various types of waterproofing and drainage systems and the repair or replacement of the structural tunnel lining.