DipPortugal
1. Dip
A dip is a low or sunken section of the road where the surface drops and then rises again over a relatively short distance. A dip can reduce visibility, affect vehicle stability and sometimes collect water, making it more difficult for drivers to judge the road ahead.
Drivers approaching a dip should reduce speed when necessary, maintain control and watch for hidden vehicles, pedestrians, cyclists or standing water beyond or within the depression.
What is a dip in the road?
A dip is a short depression in the road surface where the road falls and then rises again.
Why can a road dip be dangerous?
A dip can reduce visibility, affect vehicle stability and hide road users or obstacles. Water may also collect in the lowest part of the depression.
How should you drive through a dip?
Approach at a suitable speed, keep the vehicle under control and be prepared for hazards that may not be visible until you enter or leave the dip.

Traffic rules
Portugal