Paris ? Most French high school students began their final exams Thursday unhindered by striking teachers who had threatened to cancel the tests, though students in some southern cities had to cross picket lines to get to school.

In Toulouse, riot police with helmets and shields stood guard at one school to push back protesting teachers. In Perpignan, demonstrators blocked a bridge with tires and boulders. In Avignon, striking educators chained themselves to a school gate.

Teachers have been striking sporadically for months in protest of a pension reform proposal and a plan to decentralize the highly uniform national education system. Some transport workers have also stayed off the job to protest the retirement plan, slowing train service and subways.

The transport strikes have eased in most places, including Paris. Commuters in few cities, such as Marseille in the south, still faced hassles. In Bordeaux, where garbage has piled up on the sidewalks for 10 days, the mayor said Thursday he would hire private companies to clean up.

Transportation Minister Dominique Bussereau briefed the Senate Thursday on the cost of the strikes, saying that Air France had lost about $46.9 million since the beginning of this year. The government owns 54 percent of Air France.

Strikes had cost the national rail authority, SNCF, $305 million since the start of the year and were currently adding up to losses of roughly $23 million a day, Bussereau said.