A sign is the fastest tell there is, because it is designed to be read at speed and it almost never crosses a border unchanged. These trainers cover the two designs that vary most usefully: the chevrons stacked along a bend, and the stripes under the walking figure on a pedestrian crossing sign.
2 games, free and without an account, playable in the browser.

Which countries use the different chevron types?

Have you committed the pedestrian crossing sign stripe counts to memory?
Every game here is also in the full catalogue, which is the same list without a cut taken out of it.