Sure! Here are the completed sentences:

1. Red signs tell you something you **should do**.
2. Drivers **should check** the surfaces in their vehicle regularly.
3. Children **shouldn't play** around or near school bus vehicles.
4. 'Do Not Enter' sign indicates that you're where you **shouldn't be**.
5. Pedestrians **should wait** for vehicles before starting to cross.
6. Drivers **should take** extra care when overtaking motorcyclists.
7. Children **shouldn't ride** bikes in the road until they fully understand traffic rules.
8. If there is no sidewalk, pedestrians **should walk** on the side of the road.