International Driving License Guide: Understanding Road Signs Abroad

Triangular signs usually mean caution, circular signs with a red border mean prohibition, and circular blue signs mean an instruction you're required to follow — a pattern that holds across much of Europe, Asia, and the Middle East. Distances and speed limits are posted in kilometers almost everywhere except the US and a handful of other countries.

Unmarked intersections are where local right-of-way habits matter most. In much of continental Europe, for instance, traffic approaching from the right often has priority by default unless a sign says otherwise.

When a sign doesn't register right away, slow down and watch what local drivers do at that same intersection — usually the fastest way to figure out an unfamiliar rule on the spot.