John Lauer talked to the IT manager of a real taxi company in Arlington, Virginia [http://www.redtopcab.com]. The following is information from the conversation that might be helpful to our project.
Dispatch System
Their dispatch system is completely automated and requires no human intervention when assigning cabs to customers. At peak business hours,
they will have up to 10 reservation agents taking phone calls. The
reservation agents just answer the phone and input the customer
information. Customer information is held for 60 days. If they have a
repeat customer, the address information is automatically filled in based
on the phone number, and the reservation agent just verifies that this is
correct.
Business Volume
They receive about 2,000 calls per day. Peak hours are in the
range of 250-300 calls per hour.
Data Store
They run SQL on a Unix box, but he mentioned that there is no standard in
the cab industry.
Cab Console, Zone and GPS
Drivers do not need to call in. When they begin work, they use their
console to let the dispatch system know that they are available to take
rides. Although he said that some companies have a GPS system, at Red
Top, the drivers just enter their current zone number manually into the
console. They are then put into the queue for that zone. Rides are
assigned strictly by queue according to the zone. There is no one who
controls the location of cabs. Cab drivers can use their console to find
the number of cabs in a queue for any zone. They can then decide if they
want to queue in the current zone or drive over to another zone that has a
shorter queue.
Picking Up Customers
In the event that the cab is hailed (no reservation), when the driver
turns on the meter, the cab is automatically taken out of the queue.
For a customer reservation that comes automatically from the dispatch
system, the cab in the queue just sees the address of the pick-up. If the
cab accepts the ride, then the location of the destination is displayed.
System Maintenance
Customer and ride information data is periodically purged from the system.
Summary
It seems that our use cases are pretty much in line with this real-world
company. I thought the most interesting insights were the call volume,
zone balancing (by giving drivers visibility to the number of cabs in the
queue of any zone), and complete lack of human intervention in assigning
cabs.