For many of the commuters who must travel between the boroughs of New York City each day, theirs is the epitome of the gated city. Prior to arriving at their destinations, the hundreds of thousands of commuters who pass over or under the rivers that ring the island must wait for the gates at the toll plazas to go up to grant them entrance. It used to be that many of these drivers waited and waited, while someone up ahead discovered they were in the exact change lane without the exact change, or discovered that they left all their cash at home. The image of the testy New Yorker is born of such situations.
MTA Bridges and Tunnels, which manages the seven bridges and tunnels that connect the boroughs of the city and is the largest toll-collecting agency in the world, saw an opportunity in this early morning entanglement. If MTA were to implement an automated toll-collection system of some kind it could both improve customer service by eliminating some of the congestion and better ensure that we collected the commuter toll.
At the highest level, the E-ZPass system consists of a radio frequency transponder, the "tag" and an electronic tag-reading device. As a car drives into the toll lane, the reader reads the tag and passes the tag information to the plaza main computer, which debits the vehicle owner's account for the amount of the toll. The transaction occurs in fractions of a second-whereupon the gate goes up and the car passes through. It is slightly amusing to observe the toll plazas today-particularly when you're use to the coin-based plazas of the past-because the gates on the E-ZPass lanes have no sooner come down then they're springing back up and another car shoots through. Where there use to be a throughput of 400 to 500 cars per hour in a given lane, the automated lanes are handling twice that volume.
There's more to the system than just a tag and a reader. The system is set up to detect and protect against fraud. As a car or truck nears the toll plaza is passes through an infrared light beam that alerts the system to the arrival of a vehicle. As the reader is reading the tag, a set of light curtains, the treadle, and a set of height detectors are checking and verifying that the number of axles and the type of vehicle match the class of the vehicle as specified in the E-ZPass application. If the information gathered by the system does not match the application information, a second set of light curtains activates a video camera, which captures the vehicle's license plate and sends the information via fiber-optic link to the Image Capture Cabinet (ICC), where it is recorded on a floptical disk and sent to the customer service center. There, customer service representatives can manage the anomalous situation.
If the data gathered by the system match the tag and there is money in the customer's debit account, the gate rises and the customer can pass through. It takes only seconds.
If the customer's account is low, a traffic light at the plaza will alert him or her that it is time to put more money into the account-which the customer can do with cash, check, or credit card at the customer service centers throughout the area.
Fitting the toll plazas with the automated equipment was no simple matter. Some of the plazas are very old and accurate information about the location of conduits was not easy to obtain. Some of the plazas are on two-levels, serving upper and lower sections of bridges. Further complicating the matter was the number of different groups who were actively involved in the implementation of the E-ZPass solution-there were road-construction contractors; other contractors whose job it was to install the tag readers, video-camera circuitry, infrared sensors, and light curtains (which have to be positioned within very narrow tolerances in order to get accurate information); and third-party consultants whose job it was to link all the sensing devices to the plaza's main computer.
In all, the chief challenge was one of coordination, a challenge overcame through the use of Primavera Project Planner (P3) for Windows. The contractors and consultants had to work in numerous locations and each was planning their piece of the project with a different tool. Some were using Microsoft Project, others Primavera's SureTrak. MTA was able to pull in all these different project schedules under P3 and make a working master schedule that spanned all phases of development and construction. The software enabled MTA to see the critical path, track its progress, and re-allocate resources as necessary to keep it on the path. With so many people working independently, that would have been very difficult to accomplish otherwise.
Even with such powerful planning tools, the implementation of the automated system was not without its snags. The solution design placed a computer in every lane, a computer that would gather information from the readers, light curtains, treadles, and height detectors and send it into the tracking and accounting system for processing. To get this information from the individual computer to the plaza main computer, trenches were dug in which to lay the cable conduits between the islands and beneath the roadway.
On the Henry Hudson Bridge; however, cables could not be buried beneath the roadway because the integrity of the deck itself would have been compromised. MTA was forced to come up with an alternative scheme to get the cables to the plaza main computer. The solution, which involved raising the conduit over the canopy to the next island toll plaza, worked well, but it required different construction skills than had been allocated for digging the trenches. The planning software was able to help reallocate the resources so that the revised design could be implemented without a change in the overall progress of the project.
Indeed, the software's ability to consolidate all the information from different contractor's schedules-this information was updated from the contractors on a weekly basis-was one of the things that helped keep this project in the fast lane. Planners were always in a strong position to see where they were on the critical path. The software could tell us whether certain crews had to increase their working hours, whether multiple shifts would be more effective, or whether weekend shifts would work better. The system was constructed on a lane-by-lane basis throughout the day and night, with no permanent closures anywhere in the system, but the software helped planners figure out where to work most effectively in order to implement the project most expeditiously.
The E-ZPass system has been a huge success. More than 100,000 vehicles have been registered since September 1995. On the Monday following the opening day of the Throgs Neck Bridge E-ZPass system, more than 4,300 cars with an E-ZPass tag passed through the gates. At the Verrazano Narrows Bridge, more than 40% of the cars that cross at rush hour use E-ZPass.
Cash is still accepted, of course. Visitors don't often have E-ZPass tags on their cars, and there are still some manual and coin-operated lanes for those who need to use them. There also are some dual-mode lanes, where drivers can pay with coins or tokens or pass through automatically with the system.
Experience with the system has shown that there is always a bit of confusion on the first day, but it sorts itself out within a few days and things begin to flow smoothly.