LONDON—Britain’s goal to be a leader in adopting self-driving cars could backfire unless automakers and government regulators spell out the current limitations of the technology, insurance companies warn. Insurers are key players in the shift to automated driving, with some investing in a technology they believe will slash accidents and deaths, and save them billions in payouts. But they are worried drivers might equate today’s lower levels of automation with fully self-driving vehicles, potentially causing more accidents in the short term and permanently damaging public confidence in the technology. “What you describe things as is incredibly important, so people don’t use them inappropriately,” said David Williams, managing director of underwriting at AXA Insurance, whose parent AXA SA made €17 billion ($20.4 billion) in revenues from property and casualty insurance, including motor insurance, in 2020. “I genuinely believe the world will be a safer place with autonomous vehicles and I really …