Why is it called "drag racing?"

[Machine_Elf]

Two cars line up on a starting line. At the “go” signal, they both accelerate toward the finish line, a 1/4-mile away in a straight line; first one across the finish line wins.

Why is this called drag racing?

[steronz]

It started on main street, aka the main drag.

[Telemark]

drag | Etymology of drag by etymonline

Drag racing (1947), is said to be from thieves’ slang drag “automobile” (1935), perhaps ultimately from slang sense of “wagon, buggy” (1755), because a horse would drag it. By 1851 this was transferred to “street,” as in the phrase main drag (which some propose as the source of the racing sense).