What is the common name for a straight track built for drag racing?

The common name for a straight track built for drag racing is a dragstrip.

A dragstrip is a purpose-built acceleration facility, usually consisting of one or more parallel lanes, a starting area, a finish line, and a long shutdown section for braking. The track is straight because drag racing measures which vehicle can cover a fixed distance first, rather than how quickly it can negotiate corners. Many facilities also include a “water box,” where drivers perform burnouts to warm and clean the tires.

The best-known dragstrip length is a quarter mile, or 1,320 feet, but modern competition also uses 1,000-foot and eighth-mile layouts. The shorter distance became especially important for the fastest NHRA classes, including Top Fuel and Funny Car. At the start line, the Christmas Tree lights guide drivers into the staging beams and count down the launch.

A dragstrip is not the same as a speedway or road course. A speedway is generally an oval, while a road course includes bends and elevation changes. A dragstrip’s defining feature is its straight-line acceleration layout, followed by room to slow safely after the timed run.