feasibility study of real time parking information at ... - WMATA.com

WMATA Real-Time Parking
Information Feasibility Study
Chapter 5: OPTIONS AND PREFERRED
SYSTEM FOR WMATA
they would be managed from the local controller cabinet as well. The local staff must
have the ability to monitor the system. This should either be from a terminal located
somewhere on the premises, or through wireless devices. Again, all distribution of this
information to the local field equipment should be handled locally.
The local controller will also be responsible for all communications within that facility.
This includes communications to individual devices, as well as communications with the
central servers. Communications from the devices to the local controller can be either
wireless or wired. Communications between servers will almost always be by fiber.
The local controller must have some limited ability to archive data for use in future
planning. While the primary analysis would be conducted at the WMATA central offices,
in order to assure no loss of data, at least one or two weeks worth of information should
be stored locally.
On-Site Traveler Information
In addition to the means of providing information discussed above, the system must be
able to provide information to motorists as they approach the parking facilities. Two
methods currently in use elsewhere are highway advisory radio and dynamic message
signs.
Highway Advisory Radio (HAR)
One of the options for informing motorists is to use HAR. The biggest advantage of HAR
is that it covers all local approaches, as opposed to DMS that can only inform motorists
on selected approaches. HAR does have the disadvantage that the motorist must tune
to the correct radio station to hear the messages. This is sometimes matched with
several static signs to help promote the service.
A HAR transmitter would be located somewhere on the WMATA property. While low
power, there may be licensing issues with the FCC that must be addressed. This should
provide coverage of at least a five-mile radius, which should be sufficient to reach all
potential patrons at least ten minutes before they would arrive at the facility.
Messages are created in one of two ways – manually, or through an automated process.
Manually, a person records a message, uploads it to the controller, which then transmits
the message. This requires a person to be recording new messages every few minutes,
which would not be practical for this application. Through an automated process, after
an initial set up a computer generates the message. Standard message fragments
would be used along with the number of available spots or percent available. In this
mode, a HAR system could be very effective for a station. This automated process is
the only one that would meet the requirements – the manual process would be
extremely cumbersome to operate and very labor intensive. However, it should be noted
that the automated systems is a more expensive system to design, procure, and
operate.
There does exist the potential for different messages from different stations to interfere
with each other. The two typical solutions are to change frequencies and to synchronize
the transmissions. A different frequency does not make sense for WMATA. It would be
difficult for a driver to know which station to tune to depending on which station they
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