[…] safety in an accident. Remember that these doors open upwards — over the roof of the car. This means that the doors would not open if a car rolled onto its roof. […] Both doors open the same direction — to the top. So this means that if a car did end up on its roof, neither door would open and your Civic would become a nice little bank vault.
So, Mercedes has a heck of a solution:
Ten to fifteen milliseconds after a detected rollover, explosive bolts situated at the top of the door frame fire and bell cranks separate the doors from the car for easy exit during a serious accident