Sonic Is Getting Closer To Dominating The Burger Scene

Sonic Drive-In is currently the No. 4 burger chain in the U.S. by sales, after McDonald's, Wendy's, and Burger King. The expansion plan will bring its total number of restaurants to 4,500.

Sonic currently has less than half the number of locations as Burger King, its next biggest competitor, which has 7,100 U.S. restaurants. Sonic's sales in fiscal 2013 amounted to $543 million.

Most of the chain's current locations are concentrated in the South. Roughly 300 of the new locations will be built in California, where there are currently 65 Sonic restaurants.

Sonic sets itself apart from its competitors with a unique ordering system. Customers drive up to an intercom to order, and then a server delivers their food to their car window.

In addition to burgers, the 60-year-old chain also sells hot dogs, chicken sandwiches, tater tots, shakes, and slushies.