How to Make Your Facility LPR Ready

License plate recognition, or LPR, is an emerging technology that improves customer service, revenue collections, and facility security. Leading airports, such as Phoenix Sky Harbor, Birmingham AL, and Seattle-Tacoma are among the first to install this capability. Major airports are leading the way on LPR because they have higher percentages of overnight and multi-day patrons and higher than average daily fees. The systems specified by these parking leaders will lead to simpler LPR operations and lower prices in the years ahead, enabling other segments of the parking industry to adopt LPR.

Parking operators and consultants can take steps now to ensure that their facilities are ready for LPR, so it can be installed as an add-on with minimal disruption and expense. Here are some of the steps you can take to make your facility "LPR-ready."

Lane geometry: Design adequate straight runs where the vehicle is imaged, to facilities image capture. As a rule of thumb, cars should be constrained to straight paths 15 feet before and 15 feet after the loop detector that triggers the camera. If you have a choice about lane orientation in new facilities, favor north-south lanes over east-west lanes to minimize sun glare. (LPR systems can accommodate glare by using a two-camera system and better filters, but these cost more.)

Island geometry and camera position: In entry lanes, cameras should be placed about 9 feet before the triggering loop, that is, about 7 feet before the gate. In exit lanes, cameras should be placed about 9 feet before the rear of a typical vehicle, that is, at least 24 feet before the ticket reader. Refrain from placing signage or equipment in the camera’s field of view.

Cables and communications: Install enough cables for cameras and computers, including spare cables. The types of cables required depend on distances from lanes to computer locations and from computer locations to central offices. Fiber builds in scalability but costs more. Pulling a few extra cables when you are installing a new PAE system is not expensive; pulling new cables (and possibly laying new conduit) afterwards is much more expensive. If you are designing a facility, try to locate the parking operations office equidistant from the major plazas – you can use copper instead of fiber cabling on runs of less than 350 feet.

Computer rooms: Allow adequate space for extra lane computers, review workstations and head-end servers. Some day the computer requirements for LPR beyond those of the PAE systems may decline, but having some spare room for more computers is a good idea in this day and age.

Electrical power: The total electric power requirement of an LPR system is about 800 watts per lane, excluding air conditioning requirements. The distribution of power depends on whether the lane computers, which each consume about 200 watts, are located in the lanes or remotely in computer rooms. Where air-conditioned booths are available, as at many manned exit lanes, it is usually best to locate one or more lane computers in each booth, which increases the air conditioning load. The electrical power requirement in each lane is a minimum of 275 watts for a light source and camera. If the lane computer is located in the lane, this adds 200 watts for the computer plus the power needed for air-conditioned enclosures if no booths are available. LPR systems have roughly one image review workstation or administrative workstation for each ten lanes, and these are usually distributed in parking operations offices. It is best to allocate 100 watts per lane for the LPR system in various parking operation offices.

Parking access control equipment: Use a parking access control equipment (PAE) vendor that uses modern computer and communications technology.

Loop detectors: The size, shape and depth of detector loops, and the loop amplifier can affect triggering of LPR images. Adding extra detector loops for LPR ahead of time is less critical because you can add loops later at about the same cost later.

Being LPR-ready costs very little and can save you a lot when it is time to install LPR. If you have any questions, please contact us at lpr@alphatech.com and we would be glad to help.