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Still in a Class of Its Own

Since the 1970s, Morgantown's Personal Rapid Transit system has shuttled millions of students between campuses at West Virginia University. It still ranks as a model computerized mass transit system.

By Tom Gibson

After exiting Interstate-68 and driving into Morgantown, West Virginia, it doesn't take long to get a feel for the area's unique terrain. The Monongahela River snakes through town, and that's about the only flat feature. Rugged hills rise from the river banks, and streets wind through them taking convoluted paths.

I make my way to the Friend's Inn between West Virginia University's Evansdale Campus and Medical Center Campus, both on a plateau overlooking Morgantown and the river. Morgantown's Personal Rapid Transit (PRT) system passes in front of the hotel, offering a strange juxtaposition. The track and steel structure are rusty and drab, the concrete discolored and streaked, each showing years of use. But then, colorful and modern-looking blue and yellow cars, each the size of a small delivery van, cruise by silently. They have no drivers (and sometimes no passengers) in them.

Over a quarter century old, the PRT system ranks as the first fully-automated rapid transit system in the world. Amazingly, in an age where mass transit systems advance in technology about as slowly as airplanes (we still fly B-52s), it's still on the cutting edge. The computerized system connects downtown Morgantown and WVU's main downtown campus with the Evansdale Campus and the Robert C. Byrd Health Sciences Campus, providing transportation for WVU's 19,000 students and 7500 employees as well as community residents. In the process, it helps tame the hilly terrain.

Expansion Brings Traffic
As Bob Hendershot, systems engineering manager for the PRT system, tells it, the original idea for the system came from Dr. Sammy Elias, then-chairman of WVU's industrial engineering department. "By the late 1960s, this university had gone through a growth spurt," Hendershot relates. It originally had been located entirely downtown, but increasing enrollment dictated expanding to the Evansdale Campus, about a mile from the main campus. Several new buildings, such as the college of engineering, college of creative arts, and college of agriculture and forestry took shape there along with a large dormitory complex, and the medical center complex was built further up the hill. "Great idea, but the terrain of Morgantown and having only two roads connecting these two areas brought severe traffic problems."

WVU operated buses to shuttle students back and forth, but this only made matters worse. Jim Hatcher, systems programmer and computer engineer for the PRT system, recalls, "In the early 70s, we would actually achieve total gridlock." Hendershot adds, "At one point, the university had to not allow students to take classes at different campuses. Even in a 20-minute class change, there was no way to get to class on time."

Although an industrial engineer, Elias was more of a transportation specialist and had an interest in fully-automated transit systems. He garnered a Housing and Urban Development grant in 1969 to study the feasibility study of a system connecting the campuses. The Department of Transportation established the Urban Mass Transportation Administration (UMTA) in 1970 with a mission to explore, implement, and demonstrate new technology in transportation. Hendershot says, "Having already taken steps in this area, WVU wound up being in the right place at the right time." WVU secured a grant from UMTA to continue studying the concept and accept formal proposals for it. Several major companies submitted them.

Then came real paydirt. WVU got a grant to implement a system as a research demonstration project, being selected over other proposals largely because "a college campus was a good location to demonstrate a system like this," as Hendershot explains. "We have a captive audience. We require the students to use the system to get back and forth. We wound up having peak periods of demand every hour versus seven in the morning and five in the evening like in a city. Morgantown has the extremes of environment to test the system, from warm summers to winters with extreme cold. It's hilly area around here. The system experiences pretty much all the demands that can be placed on it. We were judged a very good test bed for a system."

Hendershot says the system mushroomed from its original design and cost estimates. "Every conceivable thing was put into it. The biggest improvement was the onboard switching capability of our vehicles, which allows stations to be bypassed. This allows direct origin-to-destination travel."

They selected a proposal submitted by Alden Self Transit, a small company in Boston. This was for a small circular test track and one vehicle, but it was the one system that featured the onboard switching capability, which formed the crux of what became known as personal rapid transit. Alden wasn't established well enough to carry out such a large-scale project, so contracts for system design went to the Jet Propulsion Laboratory (JPL). But JPL became more enamored with projects like sending a man to the moon, and they decided not to pursue it. Boeing Aerospace Company came along and obtained rights from Alden, taking over design of the system. Frederick R. Harris, a civil and transportation engineering firm in Fairfax, Virginia, served as the prime contractor for the guideway and stations. The project was built in two phases, the first coming on line in 1975 and the second in 1979.

Five stations comprise the PRT system, with the Walnut Street station at the downtown end and the Medical Center station at the other end and Beechurst, Engineering, and Towers stations in between. The circuitous guideway covers 3.6 miles between the two end stations.

Smooth and Easy
After walking a quarter mile to the Medical Center station, I embarked on a ride to the Walnut Street station downtown in search of dinner. Even as a neophyte, I found the system easy to use; you climb or descend stairs to a loading platform, insert coins in a turnstile, punch a button for the station you want, go to a loading gate, and follow directions on a sign overhead. All trips cost 50 cents for the uninitiated, but locals swipe a pass card through the machine. Soon, a car rolls into the station and eases to a stop.

My vehicle passes the Evansdale campus and then heads down a 10% grade toward the Monongahela River. Riding in a concrete trough this steep gave the feeling of riding on a luge track without the banks. After 15 minutes, I arrive at the Walnut Street station and then proceed to High Street, the main street in the business district.

Later, Jim Hatcher showed me the nerve center where computers control the system. Three people sat at control panels working in a deliberate, almost casual fashion. "This is the way we like to see it," Hatcher remarks. He explains that they operate in a form of the hours-of-boredom-interrupted-by-a-few-minutes-of-sheer-excitement mode. A lighted overhead schematic diagram shows locations of cars in the system. They were watching customers on closed-circuit TV cameras. "Our concern is not security. Our prime concern is safety." They watch for people getting into the guideway and in harm's way. They can stop a car in the area if something happens.

Ongoing Engineering Work
You might think all this is a product of the modern microprocessor age. But Hendershot says that though the system has changed since it was first built, "it hasn't to the extent one might think." For example, "Three years ago we upgraded our computer control system, but not because it didn't work. Up until 1997 or 1998, we operated with computer equipment that was installed back in 1971 and was still doing the job as it should. Maintainability was our only problem with it -- being able to buy spare parts. We have modernized a lot of the equipment over the years, but the system itself operates almost in identical fashion to when it was first installed."

"I've been here almost since day one," Hendershot reveals in detailing his history with the PRT system. He came to WVU in 1972 to get his master's degree after getting a B.S. from Ohio State in industrial engineering. "I really wasn't aiming toward a career in the transportation field." After receiving a graduate assistantship to research the software aspects of the system, "I got very interested in it. I worked here initially during the test and checkout of the software, and I've worked on every aspect of the system since then."

Besides Hendershot and Hatcher, the technical PRT staff includes a mechanical and civil engineer, two electrical engineers, and a host of technicians. Many have put in 20-plus years, resulting in a deep base of knowledge. "I think one reason people stay is that we're challenged by all the problems you could possibly imagine. You're never bored with doing the same task over and over. It really goes the full gamut," Hendershot says. Hatcher reinforces that: "This is a machine that's eight miles long and has thousands of parts. It's like a big video game."

The PRT staff usually has a few major engineering projects in progress, and they like to involve WVU engineering students in them. They assign year-long senior design projects to groups of three or four students, and graduate research assistants also work on various aspects of the system.

So how well has the PRT system worked as a research and demonstration project? When school is in session, 55 vehicles transport about 16,000 passengers a day, resulting in the system's 73 vehicles traveling about 1.56 million miles a year. With such a prolific track record, Hendershot says outsiders come in to see the system "all the time." They're mostly from cities and colleges that started with one metropolitan campus and expanded. "This type of system is really good for certain applications."

Some transportation experts don't consider the system truly PRT since the vehicles carry many people, and not all rides are non-stop from origin to destination. They label it a Group Rapid Transit system but also point out that it's the closest to a true PRT system the U.S. has seen.

In driving through Morgantown, traffic bustles in town, and it seems to have the same congestion problems as other thriving communities. But Hatcher says traffic has improved with the PRT system. "It has really helped traffic much more than the local people understand." He knows it would be a lot worse without the blue and yellow cars shuttling back and forth between campuses smoothly over the rugged terrain, as they have since the mid 1970s. It's only a matter of time until other colleges and towns copy the system.

Technical Lowdown on the PRT System

The system has 8.65 miles of guideway, which consists of a concrete running surface with sides on it. Cars travel both ways along a parallel set of tracks, turning around on loops at the ends of the track or at the stations in the middle. The guideway goes overhead on concrete piers about 20 feet high.

The vehicles run off 575-volt AC three-phase power, rectified and controlled to power the 70-horsepower DC motor that drives the rear wheels of each vehicle. A power collector mounted on the front wheel spindle of the vehicle rides on a power rail running along the guideway. Power is transferred by sprung sintered carbon/copper brushes.

Each car can carry eight seated and 12 standing passengers. Average speed of the vehicles is 14 mph, and top speed is 30 mph.

Every vehicle has a guide wheel on each side. A wheel on one side follows a guide rail in the guideway; the wheels are oversteered a half degree so they follow that side in a concept known as curb following. Both front and rear wheels steer. The steering is switched from one side to the other hydraulically to steer the vehicle. Having no physical connection with the guideway allows onboard switching, meaning when it comes to an intersection, the vehicle can follow one of two paths without the guideway itself having to physically switch and guide the vehicle.

The central control room has dual computers that automatically send cars to stations where they're needed and otherwise control them. System operators control the system during initialization, failure, or shutdown, but at other times, they merely monitor operation. Onboard vehicle computers receive instructions through two antennae by means of frequency shift key digital signals sent through inductive wire loops embedded in the guideway surface. An odometer and tachometer in each vehicle measure distance traveled and speed, supplying data to the computers. A control unit controls brakes, steering, doors, and propulsion. Four-wheel disc brakes on the vehicles are hydraulically operated in response to input commands.

By day, or in periods of high passenger demand, the system operates in demand mode, with vehicles dispatched in response to passenger requests. At night, or in periods of low demand, the system operates in schedule mode, with vehicles dispatched on a preset schedule. Vehicles are assigned to groups of passengers based on the number of people waiting for a particular destination and the length of time they've been waiting.

Each station houses control and communications equipment, including dual computers, required for controlling vehicle operations within the station area.

The guideway surface is heated in winter to remove snow and ice so vehicle tires don't slip. This can cause a collision, and wheel slippage can throw off the tachometer pulses that indicate the vehicle's speed. A heated water-propylene-glycol solution circulates through pipes embedded in the running surface. Four boiler plants along the route supply pressurized fluid using a system of pumps and expansion tanks charged with nitrogen.


Progressive Engineer
Editor: Tom Gibson
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©2004 Progressive Engineer