Community gates are complex systems that serve multiple homes or businesses. The above illustration shows how bi-directional traffic is controlled using separate entrance and exit gates. Projects of this size usually require special planning. The site should be carefully evaluated and have drawings created that show placement of all equipment, an elevation drawing, and an electrical plan. Consideration has to be given as to how security is maintained with many people using the gate. Access must be allowed for fire, medical, postall, utility, and maintenance workers. Access cards and coded transmitters both recognize individual users and can be deleted out of the system in case of loss. It is generally not advised to give home owners individual code numbers because they propagate and soon everyone in the neighborhood will have an access code. One access code can be used and given to all maintenance workers and changed monthly. Public Utilities can have permanent codes because they keep them secure. Visitors use the telephone access system to gain entry. Full power standby systems can be an important element of the system. These systems operate the entire system for up 48 hours in the event of a power failure. Safety devices such as safety loops, photo eyes, and edge strip switches should be used for added safety and decreased liability exposure. Lighting of the general area should be considered for safety and prevention of vandalism. A pedestrian gate should be incorporated if any walk- through traffic is likely. These gates are also capable of using card readers and digital keypads for entry. Gate operating equipment should be the best obtainable due to the increased operating cycles of a community gate. Access controls such as telephone entry systems and card readers should have bollards on either side of them to prevent collision damage. To avoid having vehicles following other vehicles in, a shadow loop can be used to close the gate as soon as the first vehicle passes through. To hold the gates closed a magnetic lock can be used to increase security by holding gates closed with up to 2500 pounds of force. Gates should be set back from the road so as to accommodate vehicles waiting for entry and to prevent vehicles from blocking traffic on the entrance road. Exit loops should be placed one hundred to two hundred feet behind the gate if possible. This will help exiting traffic from backing up. This drawing represents a swing gate installation. Slide gates need more space on either side of it that is slightly more than the length of the gate in order to travel back and forth.