How to turn the water on at the curb with the curb key?

Whichever way gravity will tend to take the vehicle OUT of the roadway if the brakes should fail.

Rollback curb is shaped like an "s" if you will. Valley curb is typically a "V"-shaped trough.

Their are two processes, distillation and reverse osmosis.

Water heated will turn into water vapor. Even when it's not heated, evaporation is a process that occurs at all temperature for water, so water vapor can always form.

Since the water is at a higher temperature than the ice, it transfers heat to the ice. This in turn raises the ice's temperature above its melting point of 32oF which turns the ice to water.