Toyota will invest $500 million in Uber to jointly work on developing self-driving cars, the companies said on Monday, a bid by both to catch up to rivals in the hotly competitive autonomous driving business. Toyota and Uber Technologies, the leading ride-hailing service, are widely seen as lagging the competition in developing self-driving cars. The partnership deepens an existing relationship and reflects CEO Dara Khosrowshahi's strategy of Uber developing autonomous vehicles through partnerships, rather than on its own. The deal also breathes new life into Uber's self-driving business. Since a self-driving Uber SUV killed a pedestrian in Tempe, Arizona, in March, Uber has removed its robot cars from the road, laid off hundreds of test drivers and shuttered operations in Arizona, its autonomous testing hub. The investment values Uber at $72 billion, matching the valuation Uber received in a deal with Alphabet self-driving unit Waymo this year.