More than 100,000 construction workers in Quebec began their summer holidays Friday — a two-week period police say is historically one of the deadliest times for highway drivers.

Statistics compiled by Quebec provincial police from 2003 to 2007 suggest the months of July and August are when Quebec drivers are most likely to be involved in fatal traffic crashes.

Twenty-eight people died on provincial highways during the construction holidays in 2006. The next year, 18 people died on Quebec’s highways during the same period. 

Police blame the problem on increases in speeding, impaired driving and seatbelt infractions.

Quebec legislated an annual two-week holiday for the construction industry in 1970. The legislation came into effect in 1971.

The provincial government estimates that more than one-quarter of the province's workforce takes summer holidays during this period.