Interstate 81 (I-81) in the US state of West Virginia crosses the Eastern Panhandle region, linking Virginia to Maryland. The Interstate Highway, completed in 1966, spans 26 miles (42 km) through Berkeley County, paralleling US Route 11 (US 11) for its entire length. I-81 enters the state near Ridgeway, travels northeast, bypassing the city of Martinsburg, and leaves the state at the Potomac River, which serves as the state line. The first solicitations for the construction of I-81 were published in 1959, with the first six miles (9.7 km) of freeway being opened in 1963, and the full length was completed by 1966. On average, between 45,000 and 60,000 vehicles use the freeway through the panhandle per day.