Chocolate bars are being handed out to drivers in the top of the South Island as part of a police campaign to encourage motorists to take a break.
Operation Alert, which is part of the national Safer Summers scheme, aims to ensure that drivers are stopping regularly during long journeys and are not driving while tired.
Senior Sergeant Grant Andrews said on Wednesday that police would be conducting high visibility patrols and checkpoints on highways from Kaikoura to Haast.
As an incentive to take a break, officers will be given chocolate bars to drivers.
All motorists stopped can expect to be breath tested and have their licence checked. The 4km/h speed tolerance will also be enforced.