Grumpy Old Geeks Topics Self-driving car sign recognition Topic Self-driving car sign recognition 2 mentions in 1 episode The hosts discuss how defaced street signs could interfere with self-driving cars. Mentions 222: Grumpy Old Manifestos Aug 14, 2017 1:13:43 You can trick self-driving cars by defacing street signs. 1:14:17 Graffiti all over the place ... is going to cause real problems.