The SMS should also include:
- a record-keeping system,
- inspection programs (day and night),
- reflectivity tests,
- quality control, and
- warehouse and field inventories.
Radio Frequency Identification
A radio frequency identification (RFID) sign management system uses tags and a
reader that are linked via radio frequency (RF). Because the user can detect
information, read tags, or write on tags from a distance, RFID is useful when the reader
is remote, such as for signs placed in ditches.
The tags can:
- store up to 40 bytes of data;
- tolerate extremes of temperature, noise, and contaminants;
- communicate bidirectionally and multidirectionally;
- be combined with other auto ID and non-auto ID technologies; and
- track products through production, placement, and use.
Some RFID limitations are a lack of standards among manufacturers and possible
negative effects from metals and other RF-linked systems in the area. Other barriers
include concerns about privacy, extended implementation time, high cost, and added
efficiency causing a reduction in staff.
The cost of an RFID system ranges from $1,600 to $5,600.
Bar coding contains printed information in bars and spaces of different widths and
patterns. It allows quick scanning and a low rate of error compared with manual data
entry. Bar code systems include:
- scanners and decoders to read and interpret label codes,
- symbologies, the display types for bar code bars and spaces, and
- bar code labels and label printers.
Labels are available from distributors, or you can buy software and a printer to produce
them yourself. This equipment is usually inexpensive, easy to use, and compatible with
existing computer systems.
Bar code labels have limitations:
- High print quality is necessary to produce a clear contrast between the bars
- Durability is a factor, as labels must remain readable when exposed to dirt and
- An eyes-free or hands-free environment is not possible because bar codes
require line-of-sight reading.
A bar-coding system costs from $1,000 to $15,000.
Video logging uses camera systems in a mobile unit, usually a van, to record data
along a selected route. Within the vehicle are camera, control, recording, playback,
and processing units. Limitations include high cost and a requirement of good visibility
for recording. A video logging system, including support equipment, can cost $50,000,
not including the vehicle.
Global Positioning Systems
Global positioning systems (GPSs) identify locations through ground-based receivers
that use satellite signals to define the positions. These systems can replace labels to
A standard GPS uses a receiver. For more precise (differential) positioning, the system
requires a base station or a subscription to a commercial service. Data may be
downloaded later into a computer for further analysis. Receiver costs range from $750
for accuracy to within 328 feet to $30,000 for accuracy to within one-fifth inch.
Limitations of GPS are less accuracy (at the lower cost) and the high technology speed
needed for survey quality.
Voice recognition systems convert speech into electrical signals that the computer
translates into data. These systems allow eyes-free and hands-free work
environments, with advantages such as increased productivity and worker satisfaction,
less paperwork and keyboard input, real-time reporting, and procedure standardization.
Speaker-independent systems (allowing more than one user) are costly and may be
unreliable. These systems range from $100 to $10,000. Limitations of voice-
recognition systems include limited applicability and vocabulary and speaker
Optical Character Recognition
Optical character recognition (OCR) converts human-readable symbols to
machine-readable code. It includes the ability to interpret images and is most useful in
the area of data transfer to computers. OCR allows less human involvement and may
result in more accurate data. Both humans and computers can read OCR output and
can use the data with video logging to identify signs and determine their condition in
The cost of an OCR system depends on the desired camera quality and ranges from
$8,000 to $40,000. Software prices vary also.
Radio Frequency Data Communications
Radio frequency data communications (RFDC) systems transmit data collected through
bar codes, RFID, or other sources to a central controlling computer. RFDC allows the
operator to move freely during short-range data communication. It is useful when data
verification from the host computer is needed. Physical means of data transfer, such
as cables, are not needed.
Advantages of an RFDC system include real-time data transfer and the elimination of
paper, resulting in less data loss and fewer entry errors. RFDC allows direct
communication to the home office or warehouse.
One limitation of RFDC is a need for careful system design to allow for communication
between remote terminals, base stations, and the central computer. Also, the signals
may be subject to interference.
Costs for an RFDC system range from $2,600 to $4,900, with base stations around
$5,000. This does not include the cost of computers.
Three types of computers are useful in sign management.
- Pen-based computers allow you to take notes, keep calendars and
appointments, and send and receive data, fax, and e-mail. The pen eliminates
the need for a keyboard and can also draw or point to items on the screen.
Designed for field use, these systems must have an adequate power supply,
storage, screen resolution, and communications. They must also have
handwriting recognition. Costs range from $2,000 to $4,000.
- Laptop (notebook) computers provide all the versatility of desktop computers
but are compact and lightweight. They require a surface to rest on and both
hands of the operator. Laptop costs range from $1,000 to $3,000.
- Handheld computers are smaller computers that fit in one hand and include
a keypad, display, function keys, and various ports. Printers, modems, and bar
code scanners plug into the ports. Handheld computers are sealed against dust
and moisture and are designed for field applications. Costs range from $300 to
Geographic Information Systems
A geographic information system (GIS) is a computerized database management
system capable of automated mapping technology, database management, and other
Vector GISs use points, lines, and polygons to represent features. A point, or node, is
shown by a single coordinate location. Computers usually store signs as point
features. Low-accuracy scales generally represent large land areas, and more
accurate scales show detail for designers and engineers.
A GIS requires hardware, software, trained analysts, and established procedures. The
system can handle only spatially related data, and startup time, data maintenance
requirements, and data complexity define system needs.
Software can range from $100 for a single-purpose package to $100,000 for a package
that can analyze, display, and interface with other systems. Hardware costs range from
$2,500 to $50,000, excluding system maintenance.
Electronic Data Interchange
Electronic data interchange (EDI) quickly exchanges data between computers in a
structured, machine-processible form. EDI requires a communication network,
information guidelines, data standards, and "enabling software" for moving the data.
The system can use either a PC or a mainframe.
Advantages include accuracy and error reduction, less physical data entry, faster data
transmission, lower inventory-related costs, improved productivity, and reduced
personnel. An EDI system allows a direct connection with the sign manufacturer to
make ordering faster and more efficient.
Some EDI disadvantages include a high initial cost, the need for large volume to
achieve benefit, and the impact on organizational structures and cultures.
A simple PC-based EDI system costs about $700, while a complex system will run
Sign Management Systems
The researchers studied sign management programs of various sizes and their
relationship to advanced information technologies. The following table summarizes
technology needs by three agency types (small populations of less than 50,000;
medium, 50,000 to 200,000; and large, more than 200,000).