In short , most European motoring legislation is aimed at ensuring that motorists can (a) travel safely, (b) sort out basic mechanical faults themselves, and thus be on their way as quickly as possible, without causing hindrance to others, and (c) be equipped to help deal with basic roadside emergencies, whether their own, or other people's.
On the continent, they have what is called the "Good Samaritan" law, whereby all motorists are required to stop and offer assistance in the event of a road traffic accident, so cars are required to be equipped with certain things to help in this, and to ensure that all the people involved have the best safety protection possible - which makes sense..
Therefore, cars are required to carry an emergency reflective triangle (two in Spain), a first aid kit, a fire extinguisher and high visibility jackets, or bibs for every person in the vehicle - failure to comply with this can result in an on-the-spot fine of a hundred Euros!