Redstone Arsenal's biggest gate was closed to traffic Wednesday afternoon after an unauthorized driver tried to enter just before noon Wednesday.
Rideout Road at Gate 9 had both inbound and outbound lanes blocked because of the incident, which happened just before noon.
Arsenal officials said guards activated the gate's active barrier system to stop the vehicle and take the driver into custody.
The incident damaged the barrier and crews were repairing the damage. The driver was taken to Crestwood Medical Center with injuries.
Traffic began moving again through the gate by 1:30 p.m. Outbound traffic resumed shortly before 2 p.m.
According to authorities, no more information can be given because the incident is still under investigation.