The Directorate General of Traffic, or DGT, is stepping up drug and alcohol controls this week, just as Christmas lunches and dinners get underway.
Guardia Civil Traffic Police will be carrying out more than 25,000 tests a day at control points on all types of roads at different times of day from Monday, December 15.
Alcohol and drugs are responsible for a third of all fatal road accidents in Spain. 19% of victims tested positive for drugs and 66% of drivers who died were three times over the legal alcohol limit.
The DGT has invited municipalities with more than 25,000 inhabitants to join the campaign by establishing controls in urban centres.
Last year 346 municipalities participated, carrying out more than 50,000 alcohol and drug tests.