CalTrans actually found out about it after 9 months, inspected it, then left it up for an additional 8 years before the entire sign was replaced.

https://gizmodo.com/how-one-fed-up-dude-fixed-an-awful-highw...

> For about nine months, only a small group of people knew that the Interstate 5 shield hanging above the 110 freeway was a forgery. Then one of Ankrom's friend leaked the story to a local paper. And that's how Caltrans found out.

> Ankrom had hoped he could get his sign back from Caltrans after they took it down; he figured he would hang it in an art gallery. But Caltrans didn't take the sign down. His guerrilla sign had passed the Caltrans inspection.

> More than eight years after after Ankrom's sign went up, he got call from a friend who noticed some workers taking it down. It had been replaced with as part of routine maintenance.

Shit happens

https://australianweldingsolutions.com.au/tullamarine-freewa...