The US ride-sharing service Uber has acquired the commercial transport-focused tech startup Otto as the company presses ahead with its pursuit of self-driving technology.

The announcement came as the company also announced a $300 million effort with the Sweden-based automaker Volvo Cars to develop driverless cars.

"If that sounds like a big deal - well, it is," Uber CEO Travis Kalanick said in a statement.

"In order to provide digital services in the physical world, we must build sophisticated logistics, artificial intelligence and robotics systems that serve and elevate humanity."

Anthony Levandowski, the co-founder of Otto, a 90-person start up, will now lead Uber's efforts to develop self-driving technology for personal driving, delivery and trucking in Palo Alto, California, San Francisco and Pittsburgh, Pennsylvania.

The statement did not disclose the value of Otto's purchase.

Mr Kalanick claimed 90% of road accidents were due to human error and that driverless cars would save lives.