Uber Technologies has spent more than $1 billion on autonomous vehicle technology to compete with giants such as Alphabet, Apple and General Motors. The ride-hailing company reported $457 million in research and development expenses for its self-driving unit in its filing for an initial public offering. That was up from $384m in 2017 and $230m in 2016. Those numbers also include other tech projects, such as a flying car initiative. Uber also warned prospective investors that its adjusted losses would rise in the near term thanks, in part, to those costs, Bloomberg said. Uber has invested heavily in self-driving cars, a futuristic technology that could upend its core ride-hailing service. But the company was outspent by at least one rival in the field: Cruise Automation, the General Motors self-driving arm. Last year, Cruise reported spending $728m and said the amount would top $1bn in 2019. Alphabet’s Waymo, the veteran in self-driving, does not disclose spending. Uber started testing self-driving cars with passengers in 2016. Its efforts soon hit turmoil after a bitter lawsuit with Waymo and a fatal incident in March 2018. In its Thursday filing, Uber said it had developed 250 self-driving vehicles, which had "collected data from millions of autonomous vehicle testing miles, and completed tens of thousands of passenger trips". Uber has already begun trimming its spending on self-driving cars. In the fourth quarter, it spent $89m on its research division, down from $129m in the second quarter. The company listed Waymo, Cruise, Tesla and Apple, among others, as competitors in self-driving. Uber warned investors about the potential impact to a key part of its existing business: "our autonomous vehicle strategy [may] add to Driver dissatisfaction over time, as it may reduce the need for drivers." Uber also said that it may be on the hook for a legal arbitration award worth more than $100m related to Anthony Levandowski and Lior Ron, two engineers it hired that were at the center of the Waymo dispute. The spending on the autonomous sector comes as authorities are proposing to bring in ruules to address the unique issues the technology throws up, according to Reuters. California regulators on Friday proposed regulations that would allow vehicle manufacturers to test or deploy small self-driving delivery trucks on public roads, the state's Department of Motor Vehicles (DMV) said. Manufacturers will be allowed to test autonomousdelivery vehicles weighing less than 4.5 tonnes with an approved permit from the regulator, the DMV said. It was not clear if these delivery vehicles will be required to have a safety driver while testing, as is required for passenger cars. The regulator will hold a public hearing at its Sacramento headquarters on May 30 to gather inputs on the proposed regulations. Currently, 62 companies have valid permits to testautonomous vehicles with a safety driver on California public roadways.