most legitimate taxis will be part of a taxi association, and will have a sign on the side of the car near the back listing  the name of association and a local phone number -  associação de motoristas pereira da silva, reachable at the phone (21)2245.2681, and taxi pontual on this link are legal taxi agencies which are well sought after in the city.

being mindful of the previously mentioned signs is a great way to prevent using the services of an unregulated taxi - before getting into a taxi, everyone should make sure to check if the seats in the back have head rests - considering the type of traffic and possibility of an accident, having a head rest is an important safety precaution.

overcrowding a taxi is not recommended since it poses a high safety risk - if only three head rests are available, limit the occupancy to three passengers, even if four could squeeze in.