Bi fold gates is a solution for where driveway space is crucial and there is no room for a sliding gate. 

Bi fold gates leaves fold in half, which allows the gate opening into half the space when in the open position.

For example if the gate opening was 4 metres but you can only afford one metre of area in which the gates to swing into the open position, a single or double swing gate won’t be able to do this.
With a bi fold gate, this then allows the 4 metres to swing open into the 1 meter opening space, leaving plenty of room for parking.