&gt; As many miles as Google has logged, they&#x27;re not testing at highway speeds yet -- I don&#x27;t think their driverless prototypes (as opposed to the modified Lexus SUVs) are even capable of highway speeds.<p>Tesla&#x27;s autopilot functions at up to 90mph.<p>&gt;  I think your three-year horizon for Tesla is, well, optimistic.<p><a href="http:&#x2F;&#x2F;www.wired.com&#x2F;2015&#x2F;10&#x2F;obviously-drivers-are-already-abusing-teslas-autopilot&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.wired.com&#x2F;2015&#x2F;10&#x2F;obviously-drivers-are-already-a...</a><p>&quot;Four days later, Reese, Mastracci, and Roy piled into a Model S and took off. They covered 2,994 miles at an average speed of 51.8 mph, a figure that includes the time spent plugged into Supercharger stations along the way. They had autopilot mode engaged 96 percent of the time, Reese says, using it at speeds around 90 mph. It eased the burden on the team, a big deal when you’re in a car for 57 hours straight.&quot;<p>96 percent of the time, at speeds up to 90mph, across 2,994 miles