New World First Bus started a pioneer trial test of a global
positioning system, which it hopes would help improving its service.
China Aerospace International is a company which provides technical support to the bus company.
Mr. Hui Wing Hong, the Assistant General Manager of the Research and Development Department of China Aerospace, introduced the framework of GPS.
"What we have to install in buses are small receptors that can transmit signal via satellites to a control centre," said he.
"With data received from at least three satellites through the wireless network, the whereabouts of buses could be located."
The estimated bus location would be displayed on a scrolling map in a 24-hour computer control centre.
Other useful details for fleet management, such as the route, fleet numbers and speed can also be obtained and analyzed.
Ms Kian Ng, the Public Affairs Manager of the New World First Bus, explained the functions of the system.
"The travel time of buses can be obtained through the system. It is helpful in deciding how many buses and drivers are necessary for each route to meet the bus timetable. Labour costs would thus be reduced to an economical level.
"Traffic jams could also be detected when the speeds of the buses in a particular segment of the road are far below the norm," said Ms Ng.
The company could then send vacant buses to the succeeding bus stops through other routes to ease the long queues.
On the other hand, safe speeds could also be ensured by the new system.
"The routes of buses were entered into the computer. The computer would continuously compare the position of the bus along its route to decide the safe driving speed for that section.
"Monitors are fitted into the buses. Warnings would be given if the speed is excessive. The speed would be limited to under 70 km per hour," added Ms Ng.
Besides, the in-vehicle units also serve as "black boxes", like those on aeroplanes, in which data are refreshed every five m minutes. In case of accidents, causes could be traced back.
The in-vehicle units would define the position of the buses and automatically activate the bus information announcement system. Announcements about the next bus stop would be broadcast and displayed.
This arrangement provides passengers, especially those who are visually impaired or deaf, more convenience. The time of arrival can be estimated.
This estimate, though with an error of about two minutes, would be displayed on the bus stop acknowledging the waiting passengers.
But in operation, the pilot system ran into several problems.
One problem originated from the urban road system and city layouts of Hong Kong.
"The densely-distributed tall buildings and the narrow streets blocked the transmission of signals," said Mr. Hui from the China Aerospace International.
To overcome this problem, equipment including odometer and electronic gyro was introduced to work as a complement for the satellites.
"An odometer is installed to calculate the distance a bus had travelled, while an electronic gyro can figure out the direction when no satellite signal is available," said Mr. Hui.
Another problem is deliberately placed by the US government. The US government has imposed an interference on non-military use of the system, creating an distract up to 100 meters.
"This distract is not that significant in foreign countries as cars run on straight highways there. But it is intolerable in places like Hong Kong," he said.
Nevertheless the improvement in technology has pulled the distract down to about 10 meters.
According to Ms Ng, there will be reviews on the trial test by mid 1999.
"Two or three years are necessary for our whole fleet to be operated under the GPS," said Ms Ng.
However, whether the GPS could be applied to all buses in Hong Kong remains uncertain, as other public bus companies are rather passive towards the adoption.
According to the Head of Public Relations of the Kowloon Motor Bus, Mr. Peter Kuk, they are now only conducting preliminary feasibility studies on GPS.
Citybus, which once carried out a pilot GPS program, decided to suspend the plan temporarily because of the problems in the current system.
