The French transport ministry said the fireman was "on his way to work” when his car collided with a lorry.
In a separate incident, six people were “slightly injured” when a police van hit a farmer’s truck, the ministry said without providing further details.
Transport Minister Frédéric Cuvillier demanded that all roadblocks be lifted immediately after the incidents.
This latest protest increases the pressure on President Francois Hollande's government which has already been forced into an embarrasing climbdown on a planned new environmental "ecotax" on commercial vehicles after violent protests in Brittany, a predominantly agricultural region in northern France.
Opponents of the tax, which critics say unfairly penalises remote areas dependent on deliveries by road freight, are demanding it be scrapped altogether.
