Officers were tracking cars along several points on a given stretch of road to check if their average speed exceeded the permissible limit.
Police were paying special attention to sites where accidents due to excessive speed occur most often, Robert Opas from the National Police Headquarters told public broadcaster Polish Radio.
Police have said the main cause of fatal road accidents caused by drivers in Poland is motorists failing to adapt their speed to traffic conditions.
Almost 2,500 people died on the country’s notoriously dangerous roads last year, according to police data.
The number of pedestrians killed on Polish streets is the highest in Europe, Polish Radio’s IAR news agency has reported.
The Polish government on Wednesday approved a bill tightening the country’s traffic laws in a bid to improve road safety.
Under the bill, those breaking the speed limit by more than 30 kph would be subject to a fine of no less than PLN 1,500 (USD 389, EUR 326).
Under rules that took effect in the country in May, drivers have to give priority to people about to step out onto a pedestrian crossing, as well as those already on it.