i am no lawyer but have been thinking as to how the incident could be related with the highway concessionaire's liability. in my opinion, it was its (concessionaire's) responsibility to ensure safe passage way for customers (road users). but in the same time, we can't be anticipating an every second surveillance on all spots but a regular round by its maintenance/patrolling teams. as road users, we too are bound to report/lodge with the concessionaire any unsafe condition and/or obstacle(s). let say, you file this case and eventually you win, this would then be a precedent whereby some dare-devil (driver) with an ill-intention to get a all-paid-for car refurbishment might intentionally hit any "leftover" on the highway. if this continues, the toll prices would be increased in order to meet the higher demand in public liability (insurance).