A bus is one of the safest ways of traveling on the roads that exists. It is 5 to 6 times safer than traveling by car, and despite the dramatic news we see about accidents in the news, which causes public concern, the reality is that there are not usually fatalities. In 2015, school buses were involved in 27 accidents (14 on intercity routes and 13 on city roads), in which no one died, although nine people were injured.
The majority of injuries caused in a bus accident, whether a school bus or any another type of bus, are due to not using a seat belt. Since 2007, any bus that is not equipped with restraint systems is not given a licence. Such systems are increasingly being used, although on non-school services their use is relatively low (about 20% if no announcement is made to the passengers that they must be used).
In the case of children, school buses should be equipped with seat belts and the teachers, monitors and drivers are reponsible for ensuring that the children fasten their seat belts and that they remain seated and in the right position.
Spanish legislation says nothing about children under three years old, who are not of school age and for whom we can find other restraint options, as explained in this article. However, for children of school age, those over 3 years old, a specific regulation is in place: the Spanish General Traffic Rules indicate that on buses (vehicles designed for transporting passengers which have more than 9 seats) children over three years old must use approved restraint systems appropriate for their weight and height. When these systems are not available, the seat belts must be used, provided that they are suitable for the child's height and weight.
Using a child car seat is not prohibited, nor is it obligatory. It is simply subject to the availability of an adequate seat, that it fits well on the seat and it does not encroach on neighbouring seats. There is a seat approved for use on buses in Europe, equivalent to a Group 3 seat, and it is designed for children weighing between 15 and 27 kg. It can also be folded and is flexible for easy transportation.