As we build new facilities and redevelop older properties, the Maryland Department of Transportation State Highway Administration (MDOT SHA) incorporates Leadership in Energy and Environmental Design (LEED) principles into the design and construction of “green” buildings that save energy, increase water efficiency, reduce carbon emissions and are environmentally friendly.

In 2010, MDOT SHA proudly opened its first LEED certified facility: the visitor’s center along I-70 near South Mountain in Frederick County. MDOT SHA included environmentally-friendly concepts into the design of the welcome centers and rest area project that qualified for LEED certification points.

Among the green innovations we employ are:

Daylighting

We harness natural light through roof skylights, reducing the need for artificial light. Skylights are positioned to direct light into the building while protecting the building from the elements and excessive heat from the sun.

Geothermal (or Ground Source) Heat Exchange: This is a highly efficient method for both heating and cooling a building. Conventional air-source systems take air from the outside and heat or cool it. Air temperatures vary widely by season, causing the system to use more energy in extreme heat or cold. Unlike conventional systems, a geothermal system takes advantage of the constant underground temperature (in our area that’s about 55 degrees) to heat or cool a circulating liquid.

At the South Mountain Welcome Center, a geothermal pump moves a liquid (similar to anti-freeze) through a closed-loop system to a series of wells placed 400 feet underground. In summer, liquid warmed by the air in the buildings is carried down to the well where the temperature is 55 degrees. The heat dissipates and the liquid cools before returning to the building. The chilled liquid is used to cool air distributed through an air- duct system. In winter, the liquid is cooler at the surface; when pumped underground it passes through the underground loops and is heated before returning to the building. Heat is distributed in the building via an in-floor radiant system – a series of liquid-filled plastic pipes set in the floor - and radiates into the buildings’ interior spaces.

Geothermal heat exchange is twice as efficient as a standard air-source system, saving money year-round. Our geothermal system also saves us money in maintenance: the aboveground portion of the system has a life of up to 25 years and the underground part (the ground loop of pipes) can have a usable life of 50 years.

Motion Detectors

When artificial light is needed, strategically placed motion sensors automatically turn lights on and off when a person is sensed in the room.

Permeable Walkways and Roads

MDOT SHA uses porous materials for all outside walkways. These walkways may look like traditional concrete paths, but when it rains, the material allows water to soak through to the ground below. This reduces puddling on or near the walkways and minimizes erosion caused by storm run-off. Plantings near these walkways also benefit from better access to water and nutrients. In South Mountain, we were also able to construct a green maintenance road from the Welcome Center to its nearby water tower. A plastic grid under the turf provides stability for maintenance vehicles and because the road is only occasionally used, the turf road surface requires minimal maintenance. As with permeable walkways, the green road is part of the facility’s overall stormwater management system – with the bonus of being pleasant to the eye.