The Super Busway concept
Delays due to traffic congestion in the peak period can more than treble the time it takes for buses to travel from the outskirts to any city centre compared with off-peak times. These delays are chiefly due to queues which build up at the approaches to junctions as the traffic flows reach, and then exceed, the capacity of those junctions. Bus lanes have been used before, but the benefits are greatly reduced because of misuse by vehicles.
The Super Busway strategy uses guideways to provide a more effective means for buses to by-pass these traffic queues.
How the guideway works
The guideway is shown installed on the approach to a congested roundabout, with the length of the guideway matched to that of the maximum observed queue. Additional sections of guideway can be introduced in the future if this proves necessary. As a bus approaches the guideway, the driver steers into a funnel section and this adjusts the path of the bus smoothly into the guideway itself.
Once in the guideway, the steering is controlled automatically by guide-wheels bearing against the vertical kerbs. As the bus by-passes the queue, the driver simply controls the acceleration and braking, staying alert to pedestrians crossing the guideway. A vehicle detector in the guideway prompts the traffic signal controller to give a green signal for the bus by the time it arrives at the end of the guideway and a red signal briefly for the general traffic. The bus leaves the guideway ahead of the traffic queues and progresses around the roundabout in the normal way.
To use the guideway sections, buses need to be specially adapted by fitting small guide-wheels ahead of the front wheels, attached to the steering arms. Even with guide-wheels fitted, the buses can travel safely along existing routes. It is a simple and relatively cheap operation to fit most existing buses with guide-wheels. However, in the context of a high quality SUPER BUSWAY service, operators have been encouraged to acquire new, specially adapted vehicles and to improve their marketing and customer care.
Advantages of the guideway
Unlike conventional bus-only lanes, the physical features of a guideway effectively prevent unauthorised use by other traffic as shown in the diagrams. The system is therefore self enforcing, giving this form of infrastructure a major advantage over conventional bus lanes.
Passengers who have to cross the road to reach the bus, or to leave it, have the benefit of improved pedestrian crossing facilities. At the stop itself, the kerb is raised so that there is a platform from which level boarding into the bus is available. The bus pulls up within millimetres of the platform edge, guided by its guidewheels. This helps passengers with walking difficulties and those with wheelchairs or pushchairs.
Although the time saving benefits of individual guideway sections will be somewhat different in each individual application, the Leeds scheme has demonstrated the following benefits:
- 450 metres of outbound guideway saves up to 3 minutes per bus in the afternoon peak
- 800 metres of inbound guideway saves up to 5 minutes per bus in the morning peak
- All sections create absolute consistency in bus running times peak and off-peak, thereby enhancing service regularity and punctuality.
- The final phase of 400m of guideway opened in July 1998. This has also achieved timesaving benefits.
Park and ride
The advantages in journey time, comfort and reliability which guided bus can offer will become increasingly evident as traffic levels generally rise, and there is much benefit in offering car drivers the choice of travelling on congested routes by car or taking advantage of guided bus. It is expected that 60% of car drivers who make the change will catch the guided buses near their homes. For the remainder, Park and Ride sites are being provided where suitable locations exist. The attractive and secure parking areas will enable motorists to use guided bus for part of their journey into and out of the city, thus helping to relieve congestion and improve environmental conditions within the city.
The Leeds Scott Hall Road scheme features a park and ride site to the north of the Leeds opened in July, 1998 and caters for 157 cars. The well lit car park is attractively laid out with landscaping and has security features approved by the police. The use of the site will be monitored and additional sites provided if sufficient demand exists.