💡 Can I flash my high beams as a warning in Czechia?

Only in two statutory situations — and warning about a speed trap isn't one of them. A light warning signal (a high-beam flash) is allowed instead of the horn to avert imminent danger and to alert the driver ahead when overtaking (in and outside towns). Everything else — flashing oncoming traffic about a police radar, trucker greetings, thank-you hazard blinks — is formally an offence against warning-signal rules with a band of CZK 2,000–5,000 in administrative proceedings. In practice radar-warning flashes do get fined, thank-you blinks are usually tolerated — but there's no right to it. A hand gesture isn't regulated at all.