A service road, also referred to as a frontage road or access road, is a local road that runs alongside or next to a limited-access highway. These roads are used to provide direct access to private driveways, shops, houses and other abutting properties that would otherwise be cut off by the freeway.
In the United States, service roads are generally one-way with frequent slip ramps to and from the limited-access roadway. They are usually located near interchanges, so that a motorist can exit the highway and go around to the frontage road when they need to.
They are often referred to as feeders by local residents, although the term frontage road is more common in Texas and its surrounding areas. Many service roads in the Houston area have what is known as a Texas U-turn, a left lane curving under an overpass so that drivers can make a right turn without having to stop for traffic lights.
Service roads are a common feature of expressways in the US and Canada, especially in urban areas. In New York City, for example, a major portion of the Van Wyck Expressway has one-way service roads on either side, and Long Island Expressway (Interstate 495), has them for most of its length.