This is like the real-world version of applying a userContent.css file to patch a UX flaw in a web application, except in this case he patched a UX flaw in the freeway.

As users of web applications and freeways, I think we tend to overestimate our expertise in designing solutions to the things that annoy us. This story had a happy outcome because the expert user was careful and competent. Thankfully the barrier to entry for submitting patches is relatively high.