Parking Efficiency Augmented by Smart Security Solutions
Editor / Provider: By a&s International | Updated: 4/21/2011 | Article type: Infrastructure
Today, more than a billion cars are on the road, and this figure is expected to double within the next couple decades. Often ignored is the fact that much traffic comes from drivers cruising for a vacant or cheaper parking spot — recent studies indicate drivers hunting for parking account for roughly 50 percent of traffic. Traffic congestion leads to driver frustration, which may increase the number of accidents and excessive carbon emission, which impacts air quality and raises environmental issues. Smarter parking facilities and measures ensure the security of parking facilities and quality of life for local residents, as well as relieve environmental stress related to automobiles.
There are several points in a parking scenario where modernsecurity and automation equipment can help. People are getting more concerned about environmental issues, and the ever-increasing fierce competition is forcing parking lot operators to take a closer look at a variety of methods that enable cost savings and increase customer satisfaction, said Dirk Fox, Product Management for Car Access, Skidata.
When an end user is planning a new project where parking represents a large portion of the project, such as a stadium, it is important to plan the parking facility before construction, said Chris Yigit, AutoVu Senior Product Manager, Genetec. “ALPR is a viable option when deciding how to manage parking. For example, just recently a new entertainment facility was planned, and the choice for parking was to implement a concept called pay-by-plate. The details of the technology were left to the parking operator to decide and propose. However, the concept had to be agreed upon upfront as this had a direct impact on revenue, manpower and flexibility which varies greatly from facility to facility. The specific requirements of a shopping center, stadium and airport are all very different.”
Parking spaces can often be as scarce as seats in a popular restaurant, especially in urban areas. “Reservation can help the driver avoid driving around aimlessly,” Fox said. Smart parking systems can facilitate reservations of parking spots, but this can require an additional effort of real-time space enforceability within the lot, said Elliot Martin, Postdoctoral Research Engineer, Transportation Sustainability Research Center at the University of California, Berkeley. “That generally increases costs and today still requires on-site manpower. However, in environments where reserving a spot demands a premium, such costs could be retrieved with the additional revenue earned from reservations.”
The ability to reserve a parking space can be enabled through space counting, single-space recognition and connecting to online services. “The information collected by the smart parking facility can broadcast availability within and outside the lot. When delivered to travelers, it enables more efficient trip planning and can increase revenue for parking operators through better capacity management of the lot. While permitting reservations can also increase management costs, in appropriate markets, reservations can earn revenue that ultimately exceed those costs,” Martin said. With exact counting and single-space recognition in combination with a guiding system, a car driver can be directly sent to the correct parking area, Fox added.
An area in which technology could increase efficiency is by assisting visitors in locating vacant parking spaces. This would be especially useful in larger, more crowded parking facilities in which searching for parking is time- and energy-consuming, Martin said. “Technology such as changeable message signs could tell visitors at which level there exists available parking. The challenge with this, however, is that accurately determining whether specific spots are available is still difficult for prevailing sensor technologies. It requires either an accurate and clever algorithm based on strategically located vehicle counts, or spot-specific sensors, which are more expensive. Camera technology could also support this function, but it can also be expensive, and requires sophisticated image-processing algorithms that still offer less than 100-percent accuracy.”
Faster payment would be automated with RFID technology, similar to that used for FasTrak in the Bay Area or EZPass on the East Coast, Martin said. “Payment-wise, this would remove the need for a gate at the entrance and exit, but only if it can be universally applicable to all cars.”
A more feasible modification would be to use an item that most people already have, such as credit and debit cards, Martin continued. “Some banks are beginning to embed RFID chips into credit cards, and a terminal can pull information off of the card when the card is waved close. This technology, if more widely applied, could speed up the payment process at the gate, and does not require universal adoption to work. Consumers would just have to wave the card as opposed to swiping it.”
Consideration can also be given to eliminating paper tickets and their associated hardware, using only the license plate as the means of record, said Jim Kennedy, President of Inex/ Zamir. With pay-by-plate, there are no stalls to paint and maintain, and simple enforcement is possible, Yigit added. “Pay-by-plate is a concept that seems to be catching on these days. Basically, the patron is identified by his plate; the advantages are that the plate is unique and is fixed to the car. The concept is simple, but the ramifications and benefits are huge.”
The idea of a fully-automated ticketing system can be daunting to many. “Many in the parking industry have expressed concerns over a ticketless payment system as they do not fully understand the capabilities of ALPR. They worry about such things as misreading a license plate and even duplicate license plates within the facility,” Kennedy said. “While it is possible to misread a license plate — anyone in the ALPR field will readily admit that — the difficulty it might cause is minimal to nonexistent. What has to be remembered, particularly in parking, is that you have a finite number of license plates to which the one sitting at the exit could correctly be linked; it did, after all, enter the facility at some point, so it does exist in the database in the facility.”
However, there are also psychological issues to consider. “A ticketless system could be argued to be better, but industry people have told me that drivers are more comfortable when they get something in return for their car, even if it is just a ticket. It is sort of like a receipt for their vehicle and gives them some recourse to prove they indeed have a car in the facility,” Kennedy said.
With a ticket, you have yet another number to reference and virtually zero opportunities to make an error, Kennedy said. Adding license plate numbers to tickets can also prevent car theft, Fox added.
If the number is captured and read just after the ticket is issued, the license plate number is tied to the ticket number on a server, and that means a unique identifier and transaction number are tied together on that server, Kennedy said. “The benefit of having the license plate number captured prior to the ticket being dispensed and thereby allowing the number to be printed or encoded on the ticket itself, is the ability to see if the ticket presented at exit belongs with that particular vehicle even in the event of communications failure with the central server. Swapped tickets are caught out at this point, and lost tickets can have a fair and accurate tabulation of charges made, as it is known when that vehicle (license plate) actually entered the facility.”
A parking facility is unpopulated by nature, and the safety of lone patrons should be taken into consideration. “Kidnappings or physical attacks against key facility personnel continue to be a concern with corporate entities,” said Orlando Carrasco, President of Perceptics. “A company has a responsibility to protect its employees against attacks rendered by disgruntled groups or former employees, and prescreening tools such as ALPR and driver cameras serve to qualify the vehicles and drivers coming into a facility.”
Since 9/11, there has been an ever-growing concern over the threat from terrorists. There have been many cases in which vehicles are used as weapons of destruction, said Dave Bartlett, VP of Smarter Buildings, IBM. “Deploying solutions by tagging authorized vehicles with smarter sensors such as RFID with video surveillance systems, as well as integrating smarter parking software with tenant identity management, helps maintain security and order for tenant-reserved spots. Smarter parking solutions assist in sending alarms when abnormal parking violations arise.”
More and more parking facilities at mission critical infrastructures are deemed as potential targets of terrorism and are placing a greater emphasis on security and data capture at the point where a vehicle and driver enter, Carrasco said.
“ALPR coupled with an under vehicle inspection system (UVIS) will provide necessary data that allows a gate guard to determine if that vehicle is a threat. UVIS provides a color, line screen image of the vehicle's undercarriage, so security personnel are able to identify foreign objects or alterations made that could indicate a concealed threat.”
The rationales behind using video surveillance, ALPR and UVIS are different. “Video surveillance serves to monitor the movement of vehicles and occupants as they arrive and move about the premises. However, they aid more in documenting a threat in progress, so security personnel can react,” Carrasco said.
“ALPR coupled with UVIS are preventative measures that allow security personnel to assess the potential threat and create a more proactive response strategy.”
“ALPR and UVIS systems can be integrated with bollards and gate arms once the data and the security personnel have cleared the car and its driver as a potential threat. These systems can also integrate with RFID, vehicle/occupant or scene cameras, which serve to aid security profes-sionals with their security assessments,” Carrasco said.
An ALPR system worthy for consideration should not have difficulty with either brightness, as in direct sunlight, or darkness where there is no ambient illumination. IR illumination is used for the sole purpose of capturing the best possible images for ALPR processing, Kennedy said.
“Looking at the specifications of equipment offered as license plate cameras, it can be seen that some have LED illumination that is always on, while others may have it pulsed," Kennedy said. "By being pulsed, they are several times brighter than leaving them in the always-on position, and when pulsed they are on probably 5 percent of the time, which gives them an extraordinary life cycle.“
Some suppliers offer cameras that are aimed at low-cost security applications and are repurposed to capture license plates. These cameras have always-ON LED illumination and incorporate only a small number of LEDs, which generally have a life span of less than three years, Kennedy said. “In addition, many of these lower-cost devices need to keep a fan constantly running within the camera enclosure because of the heat problem generated from LEDs which are always ON. This prevents a truly weatherproof housing.”
Pulsing the LEDs requires circuitry and logic that guarantee the pulse takes place when the shutter is open, Kennedy said. “In addition to pulsing LEDs for longer life and greater illumination, the brightness of each pulse can be altered by varying the pulse width, and this is synchronized with the amount of time the shutter is open; the ‘shutter open' time is varied in a repeatable pattern, and this provides the ALPR engine images of varying contrasts from which to make a positive read. This is no simple task, but reaps great benefits regarding the overall ALPR accuracy, as well as eliminating many of the missed or unqualified plates encountered by camera systems of lesser quality.“
Distance is another item of concern in purchasing. Lower-price cameras can claim a useable distance of up to 40 or 50 feet, while higher-end cameras can be used at distances greater than 100 feet. However, the further the camera is from the license plate, the weaker the IR illumination that reaches the plate, Kennedy warned. As illumination drops off, the shutter must stay open longer to allow enough of that light to be reflected back to the image sensor, opening a window for motion blur.
The speed of the vehicle is another consideration to account for. For parking applications, a camera that can read the license plate of a vehicle traveling in excess of 100 miles per hour, in any light, at any time of the day or in any climate may seem like overkill, Kennedy said. However, it also means the “red line” will not even be approached by most users, guaranteeing a long life expectancy for the equipment.
[NextPage]“A proper ALPR camera by design should do a number of dynamic adjustments, such as performing a series of contrast-stretching techniques on each of the multiple images taken at various contrast levels to further aid the ALPR algorithms,“ Kennedy said. “With ALPR cameras, we are not dealing with video as much as we are looking for a single clear shot of the plate,” Yigit agreed. “Adjustment of the camera, utilization of multiple exposure algorithms and IR illumination ensure top read rates in spite of environmental conditions.”
Environmental conditions are considered in the early planning stages, and camera positions and illumination sources are tuned to optimize performance under these specific circumstances.
Not all ALPR is created equally, Yigit said. “There is more to ALPR than just algorithms, although that is a key component. Image quality is just as important, because when dealing with optical character recognition, garbage in often means garbage out.”
In some regions, license plates are not entirely composed of alphanumeric characters. “Different suppliers of ALPR systems can optimize the system to read license plates in different countries and can provide on-site support,” Fox said. “There is a lot to consider in choosing a strong ALPR system, and there are only a handful that are up to the task. Those who want to employ this technology should seek suppliers who can provide the after-sale service, and who will be around for the long haul,” Kennedy added.