Federal Motor Vehicle Safety Standard 214 sets static strength requirements for the doors of passenger cars sold in the United States since January 1, 1973. The requirements have led to the installation of longitudinal reinforcement beams inside the doors.

Standard 214 has reduced the fatality risk in side impacts with fixed objects by approximately 23 percent and has reduced hospitalizations by 25 percent. In collisions with fixed objects, the standard has reduced both ejection and nonejection casualties. The beam enables the car to take a more glancing trajectory, resulting in a wider, shallower damage pattern and a generally less severe collision.

In angle collisions with motor vehicles, Standard 214 has reduced hospitalizations by about 8 percent and has had little or no effect on fatalities. The standard has been effective in reducing door intrusion when the impact is centered on the compartment;​ in such impacts, the near side occupants risk of torso and leg injury is significantly reduced. The standard appears to have little effect on other types of injuries in multivehicle crashes, nor does it enable a car to take a more glancing trajectory in these crashes.