The Triangle Expressway (TriEx) is the first modern toll road built in North Carolina, and one of the first toll roads in the United States built to use only electronic toll collection instead of toll booths. The overall freeway consists of two segments called the Triangle Parkway and the Western Wake Freeway. The six-lane Triangle Parkway extends the pre-existing NC 147 3.5 miles (5.6 km) in Durham County to meet NC 540 in Morrisville in Wake County.