And a sufficiently smart compiler could optimize Common Lisp to run as fast as c: <a href="http:&#x2F;&#x2F;c2.com&#x2F;cgi&#x2F;wiki?SufficientlySmartCompiler" rel="nofollow">http:&#x2F;&#x2F;c2.com&#x2F;cgi&#x2F;wiki?SufficientlySmartCompiler</a><p>The fact is that GPS navigation is a mature field (I.e. unlikely to get much better very soon), and is still very failure-prone. I just took an Uber this morning and twice the GPS got confused between the street I was going to and the on-ramp to the highway (the two roads were narrow and unusually close together). Twice, the driver followed the GPS instead of looking with his eyes at the road (the on ramp clearly looked like an on ramp). I run into these sorts of things 2-3 times a month.