Autonomous trucking company TuSimple has achieved unicorn status on Wall Street with a fresh funding round that values the start-up at $1 billion.

The company said Wednesday it raised $95 million in a series D funding led by Sina Corp. and Composite Capital, a Hong Kong-based investment firm, as it prepares to expand its testing of self-driving semis on highways in Arizona, New Mexico and Texas.

"By the end of 2020 or early 2021 we think we think we can take the driver out of the cab on trucks," said Chuck Price, chief product officer of TuSimple.

San Diego-based TuSimple is developing technology to allow shipping companies to operate self-driving class 8 tractor-trailers, potentially eliminating the need for drivers, the biggest expense facing trucking firms today, especially in a tight labor market. On average, shipping firms spend $2 per mile hauling goods, a cost TuSimple believes it could cut by 30 percent by eliminating the driver with autonomous trucks.

The money will help TuSimple expand its fleet of 12 test trucks to more than 50 by June. The company is currently testing autonomous semis on routes between Phoenix and Dallas."

The extra cash will also help the company develop joint production of autonomous semis with truck manufacturers. TuSimple is currently working with two tractor-trailer makers, which it is not naming.

There are just under 3.5 million semis on the road in the U.S., according the American Trucking Association. They are the heartbeat of an $800 billion freight shipping industry TuSimple executives believe will continue growing.

"With e-commerce growing by double digits every year, freight shipping is not slowing down," said Cheng Lu, CFO of TuSimple

Most of the attention surrounding the development of autonomous vehicles has been focused on self-driving cars and the race to build autonomous ride-hailing companies. Alphabet subsidiary Waymo, General Motors subsidiary Cruise and Uber are just a few of the companies that have dominated headlines with their work on self-driving cars. By comparison, the potential of autonomous semis has not received as much attention.

That could change as TuSimple and others demonstrate tractor-trailers can drive autonomously from shipping depot to shipping depot. "A big milestone will be showing that on one route we can take out the driver completely," said Price.

TuSimple is not alone in the push to develop self-driving semis. Embark Trucks, Ike, Starsky Robotics, Thor Trucks and Udelv are also working on autonomous trucks.

Correction: This story was revised to correct the date of TuSimple's announcement to Wednesday.