Kevin Slaughter didn't know the exact location of his 1,500 trailers at any given time. The vice president of operations for James Brown Trucking of Lithonia, Ga., a regional dry-van and flatbed carrier, says his company relied on drivers to jot down trailer locations when they dropped off or picked up cargo from customers. "We also had someone who worked 40 hours a week doing nothing but chasing trailer locations," he recalls.

That method clearly was inefficient and costly, and Slaughter was anxious to change that situation. "One of our goals was to find out where our trailers were so we could reduce our number of trailers or create more revenue from our existing trailers," he explains.

Since Brown implemented tracking technology from Ottawa, Ontario-based Vistar Telecommunications, drivers no longer need to record which trailers are sitting at customers' facilities. Instead, the carrier electronically receives location data every 15 minutes from devices attached to its trailers. That information flows from Vistar's system into the motor carrier's internal information system. "The integration into our software is as important as the information itself," notes Slaughter.

That newfound ability to get up-to-date location information has had a noticeable impact on Brown's efficiency and costs. "What took 1,500 trailers before may take only 1,300 trailers now," Slaughter says. When the full-time equipment tracker left, moreover, that position was eliminated.

Implementing tracking technology, moreover, may have done a lot more for James Brown Trucking than improving the carrier's own efficiency and cost control. It may well have made the difference between keeping and losing customers, or even getting new customers. A recent study by Edward Frazelle, director of the Logistics Institute at Georgia Institute of Technology, found that tracking and communication capabilities ranked among the top five priorities for shippers when picking carriers—right up there with on-time delivery, cost, and safety.

As more shippers seek real-time visibility of their over-the-road shipments, they are pushing their carriers to incorporate tracking technologies. One of the hottest areas for equipment tracking these days is wireless technology, which has gotten a boost not only from increasing demand for inventory visibility but also from the need to better manage drivers' activities and more carefully monitor cargo security.

Wireless tracking technology has made considerable strides since it was introduced more than a decade ago. At first, motor carriers equipped their tractors with Global Positioning System (GPS) equipment. GPS is a radio navigation system that uses orbiting satellites to fix ground locations and facilitate communication between drivers and dispatchers through a central data management center operated by the technology vendor.

Later on, the adoption of cellular telephone technology enhanced driver communications. Low cost has made cellular technology especially popular as a way to send satellite information to data centers. "[The cost of] cellular technology keeps coming down, driven by consumer demand," says Thomas Doyle, vice president of business development at Qualcomm, the San Diego provider of communications technology. "It's finally hit the point where it can be delivered inexpensively."

The latest trend in transport communications involves tracking untethered trailers—that is, trailers that have been separated from a power unit. "Shippers used to think it was important to track the truck, but when a shipper can track a trailer that is carrying its cargo, the company gets interested," explains Todd Felker, vice president of marketing for Terion Inc., a tracking technology company in Plano, Texas. "The cargo information is important for security and for tracking inventory. Shippers are beginning to say, 'If you want to carry our cargo, you need to have trailer tracking'."

For companies that simply want to know a trailer's location, the full GPS navigation processing system isn't necessary. Instead, many are turning to low-power global location systems (GLS). A GLS device picks up a satellite signal and relays it by "Wi-Fi" to a processing center, where its location is calculated. Wi-Fi stands for "wireless fidelity." It refers to the transmission of computer data by means of radio waves at high speeds over distances up to 300 feet. Wi-Fi products operate on the so-called IEEE 802.11 specification for radio transmission.

Since the devices used to monitor trailers only transmit a signal and do not process location information, they require very little power. That keeps the cost per unit low. Devices provided by SkyBitz of Dulles, Va., for instance, use simple AA batteries. "At one message a day, the batteries inside the device last seven years," explains Andrew Wood, chief executive officer. "So the carriers only have to touch the asset once in its life."

A different solution from GE TIP in Devon, Pa., blends new and existing technology to track a wide variety of data on trucks and trailers. The General Electric subsidiary utilizes GPS, low-orbit satellite, and Wi-Fi to manage data. "The tracking device is talking to both a GPS satellite and a low-earth satellite, which transmits the signal to a Wi-Fi ground receiver and sends it to a network data center," explains Patrick Brennan, communications leader. Once the network has been set up to gather and deliver data, whether by GPS, low-earth satellite, or by Wi-Fi, virtually any type of sensor can send information to GE TIP's system.

Brennan predicts that shippers and carriers will soon use wireless technology to control trailer movements. "You'll see the development of 'geo-fences' that let a company determine where its trailers are authorized to go," he says. A system including a geo-fence—in essence, a predetermined geographic parameter— would send a message to the company's data center if a trailer left its authorized geographic area.

Providers of tracking technology already have found a host of other uses for their versatile products. For example, the combination of geosynchronous (or fixed) satellite technology, low-earth satellites, and Wi-Fi lets companies monitor vehicle location, drivers' activities, and cargo data with a single application.

This type of solution blends passive GPS map location and active automatic vehicle location to give drivers directions to the next stop. The network that exchanges information with the driver uses Wi-Fi technology. Sensors gather information about a vehicle's location and send it to data centers, which process that data and furnish dispatchers with information about drivers' activities. Drivers and dispatchers can then interact through a display terminal mounted in the cab, explains Tim Van Cleve, chief operating officer of Los Angeles-based Teletrac Inc., a tracking technology company.

That's a benefit for shippers and carriers that track the activities of drivers who perform multiple pickups and field-service calls each day. "This technology removes the clipboard from the driver's hand and creates a virtual clipboard," says James Quigley, director of business development for the Enterprise Solutions Division of Aether Systems Inc. in Owings Mills, Md. "Now the driver's day is managed by the virtual clipboard, and the back office has a peek into the driver's activity," he says. "Customer support is right in the truck with the driver."

The increasing emphasis on cargo security also has provided fertile ground for new wireless applications. Vistar's system, for example, can tell users much about what goes on inside their trailers while they're on the road. "For high-value or high-security loads, we apply a number of sensors," explains Vistar President Neil Knudsen. Those sensors can tell whether the temperature is rising in a refrigerated unit, whether cargo has been removed before it's time to unload it, and whether the trailer is empty when it's supposed to be full, he says. GE TIP's service offers similar capabilities.

Wood of SkyBitz says the added security provided by wireless tracking technology can make it easier to get cargo insurance coverage. "Some insurance companies won't insure the load unless it has good security," he says. But Slaughter says that although wireless tracking technology has helped locate stolen trailers and cargo, that hasn't yet translated into lower insurance costs.

Shippers that are concerned about security also like the reliability of satellite-based systems. During the mid-August blackout that covered the Northeastern United States and Eastern Canada, for example, Vistar's offices in Ontario went black. But back-up generators kept its data center live and the satellites weren't interrupted even as cellular networks collapsed. "We were not out at any time during the blackout," Knudsen says.

Not all loads, of course, are valuable enough to warrant the cost of sophisticated tracking technology. That cost varies depending on the amount of data required, the breadth and depth of the coverage area, and the frequency of transmission. Per-unit costs (excluding hardware installation) can be as little as a few dollars per month if a company only needs a location reading once per day. Costs increase as companies add requirements such as additional sensor readings and increased data-transmission frequency. Additional expenses come with systems that take incoming data and integrate it into software such as an enterprise resource planning system.

Even if a shipper is moving cardboard boxes, though, there's a benefit in knowing where each trailer is located. For that purpose, inexpensive devices that send a signal once per day may be sufficient. Fortunately, the variety of technologies available today lets carriers match their technology investment to the needs of their shipper customers.

Many experts believe that in the future, wireless tracking technology that's now being used to keep tabs on tractors and trailers will be applied to smaller unit loads. "The progression will go from trucks to trailers, to pallets, to cartons, to products," forecasts Terion's Felker. Wireless trailer tracking, in short, may lead to a host of applications that will make it possible for shippers and carriers to "see" their transportation and logistics activities like never before.

Robert Spiegel is a freelance writer who specializes in technology and the electronics industry.