When checking vehicle tyre pressures, what is the correct procedure to ensure accurate readings?

1. Check tyre pressure when the tyres are COLD (before driving or after traveling less than 2 km at low speed)
2. Check tyre pressure immediately after driving for 2 hours on a high-speed highway
3. Release half the air from the tyres whenever driving on paved roads
4. Tyre pressure only needs to be checked once a year during annual registration