"Phoenix Sky Harbor has always been one of the leaders ith parking technology. We were the first to use the Electron system 20 years ago and now are the first with a working License Plate Recognition system today." Thus Tracy Revas, land side operations manager, summarized the philosophy at the Arizona Airport. "We wanted vision! We were looking for a system that would serve the needs of our airport for the next 20 years."
And vision they got. According to their consultant, Harold Schulke of Kimley-Horn and Associates, the system "brings to bear technology that is being used in other industries than the parking industry. It's truly a leap over current technology used in the market."
The system is huge, covering 15,000 spaces, 29 exit lanes and 31 entry lanes. All equipment is online with a central processing system running on redundant HP 9000 servers using Unix. Communications are on the airport's fiber optic system, with workstations running on Windows NT. Fifty pay on foot machines are being added this year as part of the second phase of the system.
"We did some things that had never been done before," said Revas. "We knew there would be some problems, we expected them, and worked through them. We never had a doubt that we were going to succeed." The selection committee for the new parking system convinced itself that the vendor could succeed before they entered into the contract.
They spared no expense, visiting not only current installations, but also the factory in Europe.
Only two companies answered Sky Harbor's specifications, Scheidt and Bachmann from Germany and PES from the UK. Scheidt and Bachmann won the bid. On the surface the system seems fairly routine. Ticket on entry, pay on exit, license plate inventory, all information feeding back to a central control center. What makes it different, according to Shulke, is the technology that is driving the system--the open architecture software, and License Plate Recognition (LPR).
The industry has been watching Phoenix Sky Harbor for over a year as the LPR system, built by Alphatech in Massachusetts, took shape. "There was no question that this was going to be the biggest single issue," said Revas. "We knew up front we were cutting new ground here and there was going to be a shakedown period."
In addition to getting the LPR to work in the glaring Phoenix sun was the issue of making the interface between the LPR system and the revenue control system function. Does it work? "Yes," says Revas. The numbers look like this: The system reads 92 percent of all readable license plates perfectly. This assumes there is a plate on the car and it's not obscured by a trailer hitch or dirt. Furthermore, in 99 percent of the cases, it reads all of the numbers on the plate less two. For example: If the number is ABC1234, the system would read AB 1 34--enough to match on exit, but not perfect.
Any plate that isn't read perfectly is shown to a person in the central office who can look at the picture and make an adjustment if necessary. "The system is set now to not be very forgiving," according to system software engineer, Joerg Scheffler. "We want to run it in the beginning so that it rejects any plate that the system feels it may not have read properly. We are finding that the vast majority of these advisories are good reads. We just want to be sure."
When the car pulls into the lane, a ticket is issued. When the vehicle leaves the entry lane, four digital pictures are taken of the rear of the vehicle. "We get four views of the rear of the vehicle as it drives away," said Scheffler. "That way we can pick up the plate almost anywhere on the rear of the car." This method also mitigates the strong "glare" factor at the desert airport. The ticket number is "linked" to the license number in the system and again compared with the license number on exit.
The most significant problem engineers faced with LPR at Sky Harbor was the extremely bright sun. After "tweaking" both hardware and software for a few months, they eventually yielded to Mother Nature and installed "shade structures," large tent-like awnings to permanently shade
the exterior exit lanes.
If the computer "thinks" it cannot read the license number perfectly, an alarm sounds and the central staff can manually look at the pictures captured by the system and correct or adjust the license number. This task can be done anytime for the entry lanes. For a "misread" on exit, the staff is immediately alerted and the picture is manually checked, normally before the vehicle stops rolling at the exit booth.
The LPR will continue in full effect when the pay on foot stations are added this Spring. "The system will operate exactly as it did before," says Shulke. "It will compare the license number with the ticket. If all matches, it will allow the transaction to proceed. If not, the alarms sound
and supervisors take whatever action is necessary."
The system is fast. The ticket is issued within 2.5 seconds of the person pushing the "take ticket" button. On exit it's even faster. "We would regularly back cars up into the floors of the garage during peak exit times," said Revas. "We haven't had a backup since the first day the new system was installed. And that includes the time taken for LPR."
The new Phoenix system also has a credit card component. Customers can use their credit cards at exit lanes. They just insert their cards in the ticket acceptor after the ticket and the charges are cleared within four to five seconds. "We are always online with the clearing house," says Shulke.
Currently about 30 percent of the transactions are credit card at the terminal used by business travelers, 10 percent in the rest of the system. "We see that number growing weekly," notes Scheffler. "I think the number may be up to 30 or 40 percent system-wide soon."
"With a couple of minor exceptions, we have been on schedule," says Revas. "Most of the time when there was a hiccup in the delivery schedule of the system, it was our fault. We have major construction going on here at the airport and oftentimes our subcontractors were unable to keep up with the infrastructure installation schedule. You can't expect the system to run, for instance, if the communications cable wasn't installed. Plus we cut the communications lines a number of times during installation. This kind of thing is to be expected.
"The biggest benefit for me? Reports. Last year, we needed some entry and exit lane peak traffic flow information. It took our operator a week to collect the data by having staff stand in the lanes and count cars. Last week I got the same data from the system in less than an hour.
"Another real benefit," Revas added, "is tracking insufficient funds (IF) transactions. The system keeps such transactions in its database and should the vehicle show up again, we know that they had an IF transaction in the past and can actually collect the funds at exit for the prior transaction. This isn't a huge number, but it closes one more hole in the system.
"Problems? Of course there were problems. We knew we were on the cutting edge and expected that. Trying to make LPR work in the desert sun was a big hurdle, as was the computer interface between the LPR and the rest of the system. But we kept at it. We knew if it would work here, it would work anywhere. And besides, someone has to be first, and we have always been the first. Our vision is to plan for the future, not just purchase what is available for our current needs."
The major requirement of the supplier was that the system be expandable, according to Revas. Virtually all of the components are running at about 50 percent capacity. There is plenty of room for growth. And based on the Sky Harbor traffic growth, they are going to need it.
February 2000, Parking Today, www.parkingtoday.com
