If your driveway slopes up, toward the residence, you may need to have your gates open out, toward the street. The alternative is to have the gates set high enough off the drive when closed so they will clear the high point of the rising drive slope when fully open. You can determine this height by laying a flat 2×4 from the proposed gate setting to half the overall width up the drive. Using a level, you will raise the end of the 2×4 at the gate end and measure the distance between the bottom of the 2×4 and the drive surface. It should be noted that with out-swing drive gates, the armature on the motor requires more clearance, robbing the rough opening width by approximately 7 ” per motor-arm. If the motors are exposed, mounted to the street side of the gates, this is avoided, but the exposed view of the motors is a trade-off.   You can also opt for the Viking I-8 In-Ground motors, allowing for out-swing (or in-swing) with a motor that is set below the drive surface directly beneat the gate. In-Ground motors are popular, and are covered with photos on Drive Gate Specifications

Most communities have an ordinance that no drive gate can swing out unless it is set a minimum of 12′ in from the street. Obviously this is to avoid your vehicle from stopping in the street, waiting for your gates to open and allow you to access your drive.