Real-Time's Rapid Growth

Los Angeles County’s new red-themed priority bus service known as Metro Rapid has the green light to expand after proving the success of its program for attracting new riders: bus service that is significantly faster and more reliable and eye-catching electronic displays that tell passengers waiting at stops precisely when buses will arrive.

Increasing bus ridership is a top priority for greater Los Angeles—the home of more than one-third of California’s residents and the birthplace of such terms as smog and gridlock. More than 90% of home-to-work travel takes place in passenger cars, according to the Auto Club of Southern California. And population growth far surpasses the capacity of the street and highway network to absorb more traffic. While the region continues to expand its rail system, buses remain the dominant mode of public transit and are the best hope for relieving the ills of traffic congestion.

Buses, however, have not always earned a very good reputation with the traveling public. A 1995 study by the L.A. County Metropolitan Transit Authority (MTA) confirmed passengers’ frustration with slow-moving buses that leave riders waiting at stops without a clue when the next bus will come along. The same study found that MTA buses were actually in motion only 50% of the time; they spent as much time stopped at traffic lights and at bus stops as they did traveling along their routes.

The MTA designed Metro Rapid to make riding the bus more attractive. The new service uses the city’s computerized traffic signal control system to move special red-painted buses through intersections faster. Just as important, it has developed a new passenger information system that uses wireless electronic displays at a majority of its bus stops to improve rider morale.

Since a demonstration project on two of L.A.’s most heavily traveled corridors began in June 2000, the Metro Rapid service has achieved 25% faster travel time and increased bus ridership by 30%. Based on that success, county transportation officials have given the green light to expand Metro Rapid service throughout Los Angeles.

The project’s goals were achieved by applying crossover technologies and forming a working partnership among several public and private organizations. The key was leveraging the Automated Traffic Surveillance and Control (ATSAC) system operated by the city of Los Angeles Department of Transportation (L.A. DOT) to create a real-time solution that coordinates bus movements and rider expectations. The ATSAC system controls the lights at more than 3,000 intersections, monitors the location of each Metro Rapid bus and relays arrival information messages to bright light-emitting diode displays mounted on each Metro Rapid bus station.

Every morning the MTA gives the L.A. DOT command center staff the schedule for each Metro Rapid bus that day. A transponder mounted on the chassis of each bus documents its route progress via sensors installed at each intersection. Throughout the day an ATSAC computer compares that schedule with the actual location of each bus. If the bus falls behind schedule the computer can hold the traffic signals at green in its immediate path so it can catch up. Since the computer knows the location and speed of the bus, it can calculate the time the bus will take to reach its next stop and transmit that information for display to waiting passengers.

Among riders accustomed to waiting at stops without much idea when the next bus would show up, the electronic displays that count down the approach of the next Metro Rapid bus are information beacons that reduce anxiety.

"Bus passengers have been excited about the displays because they present brand new information and they’re accurate to within 60 seconds," said Rex Gephart, Metro Rapid’s project manager. "They love the idea that they can tell when the next bus is coming."

The signs, specially modified versions of InfoWall electronic displays manufactured by Trans-Lux Corp. of Logan, Utah, are driven by information from the ATSAC system. The one-line panels mounted 9 ft above pavement level display a simple, powerful message in 2-in. bright red characters. An example may read: "NEXT BUS IN 5 MIN."

Each message travels from the ATSAC center to AT&T’s nationwide cellular data network, which relays it to a wireless cellular digital packet data/Internet protocol modem built into the electronic display at the target bus stop.

Each modem-display unit has its own unique IP address so a series of stop-specific messages can be cascaded along the route to update passengers when a Metro Rapid bus will arrive at their particular location. The modems re-encrypt themselves after each message to deter hackers, and a software interface written by Trans-Lux sends a real-time mirror image of the currently displayed message back to the ATSAC center for verification. Both message and mirror image travel back and forth in nanoseconds. The bus stop displays can be programmed to show a default message in the event communications with the ATSAC center are lost.

Using wireless modems to communicate with the InfoWalls holds a lot of appeal for the L.A. DOT.

"We have tested and evaluated packet data technology for traffic signal applications. It is very valuable and reliable," said An Nguyen, L.A. DOT project manager. "And we don’t have to dig up the streets."

The department evaluated five suppliers of LED displays before selecting Trans-Lux, which constructed a prototype InfoWall unit that incorporated the designated cellular modem supplied by SafeTran Traffic Systems, Colorado Springs, Colo. The displays have hi-brite characters that are easy to read from a distance in any lighting conditions and comply with the Americans With Disabilities Act. The display housing, configured to fit the design of Metro Rapid’s new bus shelters, is made of 11-gauge steel housing for extreme durability and accommodates a low-profile "hockey puck"-style modem antenna.

The chief benefits of wireless versus wired implementation include faster, cheaper installation and lower operating costs. The InfoWall-CDPD/IP modem units are entirely self-contained and can be easily installed, relocated or replaced. Each modem incurs an $8 monthly charge from AT&T, but the cost of usage is low because data is transmitted in one or two seconds every two minutes on average.

For the Metro Rapid demonstration project, the MTA constructed 48 new high-tech bus shelter/kiosks along the Wilshire-Whittier and Ventura Boulevard routes. Besides real-time displays, the shelters provide maps of the entire Los Angeles County public transit system and information on fares, transfers and schedules.

In its first two months of operation, nearly 70,000 riders a day were drawn to the gleaming new Metro Rapid shelters.

"The Metro Rapid program has been outstanding," said Gephart. "It has been one of the bigger hits of the city of Los Angeles in the last 10 years."

Metro Rapid’s new Public Information System has already drawn the interest of other transit agencies, including Los Angeles International Airport’s parking lot-to-terminal bus service. It may be particularly valuable in situations where a set schedule cannot be maintained and passengers would be greatly reassured to see continuously updated messages showing the progress of a bus or train to where they are waiting. The underlying technology—cellular modem, data network and electronic display—can be applied almost anywhere that dynamic information is needed in remote locations and running cable is not an option. Portable message displays alongside highways and signs to direct people at public events are examples of the potential for timely, accurate information delivered to remote locations.