Another confusing one - though at the city level - is Vancouver, Washington vs. Vancouver, British Columbia. It’s been a while since I’ve been in the Pacific Northwest, but I seem to recall I-5 signage giving those two options, one north and one south. I’ve always wondered how many drivers picked the wrong one at a glance and ended up at an international border.

Edit: Once I took a Lyft/Uber in midtown Sacramento. Midtown Sacramento is on a grid where north-south streets are numbered and east-west streets are lettered. The driver wasn’t familiar with the Latin alphabet. So what would seem like the simplest structure was, in that case, inscrutable.