TUCSON, Ariz. — TuSimple Holdings needs closure on a raft of investigations before it can reclaim technology leadership in the nascent autonomous trucking industry. But a balance sheet with nearly $1 billion is a big advantage. “Our runway is three years, and that’s excluding any strategic decision on China,” TuSimple Chief Financial Officer Eric Tapia told FreightWaves in an interview at the company’s testing operations site. “China’s a great business. They have some interesting initiatives with OEMs. But right now, even if we wanted to, we cannot sell it as we have this regulatory cloud.” It is more than a…