It’s pretty difficult at this point to determine which automaker is the most serious about developing self-driving vehicles in the United States. General Motors, though, might have plans to distance itself from the pack. The U.S. automaker plans to soon deploy 300 Chevrolet Bolts fitted with self-driving technology, Spectrum reported Friday. If true, GM would sport the world’s largest fleet of autonomous vehicles, placing it well ahead of Waymo, which currently owns the largest such fleet at nearly 80 vehicles. GM currently has around 50 driverless cars deployed across San Francisco, Scottsdale, Ariz., and Detroit. In addition to expanding its vehi... NESN.com