A major metropolitan region has constructed a series of toll roads. Each toll road has a series of fixed checkpoints consisting of one or more tollbooths, which serve as collection points for the toll
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fees. Customers who use the toll road may pay the tolls by using a transponder placed in their vehicle or by paying with cash or credit cards at selected tollbooths. Customers wishing to use automated transponders purchase these transponders through the regional toll center. This regional center maintains customer accounts including owner and vehicle information, account balance, and history. Account number, parent region, and remaining balance are encoded within the transponder and can be used in a federated system with other cooperating regions using the same transponder format. The regional facility must then accept transaction updates from other regions on a periodic basis. There are five kinds of tollbooths used in this system: 1. High-Speed / Transponder Only 2. Low-Speed / Transponder Only 3. Transponder / Exact Change 4. Transponder / Credit Card 5. Full Service All tollbooths consist of an entrance light to indicate whether the tollbooth is operational; a vehicle-approaching sensor (placed 50 feet in front of the tollbooth); a vehicle-passed sensor; an exit light to indicate the toll has been paid; a transponder sensor; a camera; and an alarm. Additionally, all tollbooths other than the high-speed / transponder-only lanes contain a vehicle barrier that is raised and lowered to enforce payment and a display to indicate the required toll. Transponder / exact change tollbooths have a money collection device, while transponder / credit card tollbooths have a card reader device. Finally, full service tollbooths do not have change collectors or card readers, but instead have an operator that collects the appropriate toll and authorizes a car to pass. (Note that transponders may be used in any tollbooth.) Toll rates are determined by the time and day and by the number of axels on a vehicle. Each checkpoint is assigned a specific set of toll rules. An operator at the regional facility is responsible for setting and changing the toll rates. The exit light at each tollbooth is initially red and, if present, the barrier is lowered. When a vehicle approaches the tollbooth, the vehicle sensor detects the vehicle’s presence as well as the vehicle type. If the transponder sensor detects a valid transponder in the approaching vehicle, it reads the current balance to determine if there are sufficient funds. If there are sufficient funds, the toll is deducted from the current balance and the transponder is updated with the new balance. The exit light is turned to green and, if present, the barrier is raised. The exit light is returned to red and the barrier lowered after the car passes. If a vehicle passes through the tollbooth while the exit light is still red, an alarm sounds, the video camera photographs the license plate, and the image is sent to the local police liaison office. 2 Customers not possessing a transponder (or having insufficient funds on their transponder) must use an exact-change, credit-card, or full-service tollbooth. In each of these cases, the toll is calculated based on the time, day, checkpoint location, and vehicle type (number of axels). The toll amount is displayed for each vehicle as it approaches the tollbooth. For exact change tollbooths, a money collector accepts US nickels, dimes, quarters, and $1 bills. Credit-card booths accept MasterCard and Visa credit cards. For full-service tollbooths, an operator manually collects the required toll and authorizes the vehicle to pass. When the required toll has been collected, the barrier is raised and the light is changed to green. [Less]
