London Heathrow CTA Study Assessment
A summary of the following is available on the London Heathrow CTA Study page.
This case study was made as part of a project for the Department for Transport, with the collaboration of the British Airports Authority. The new Terminal 5 is scheduled to open in 2008, and this will provide a window of opportunity for redevelopment of the Central Terminal Area (CTA), since activity at Terminals 1, 2 and 3 will decline because of transfer to T5, though it is expected to grow back to current levels within a few years.
The application studied was of a PRT network linking the Pink Elephant and Park1 business car parks north of the CTA access tunnel, plus the N4 staff car park, with the three terminals plus the Queens Building for administration staff. At present the car parks are linked to the CTA by shuttle bus services: Park1 has a dedicated limousine service to Terminal 1 only, Pink Elephant has a 5-minute bus services which drops passengers at the three terminals in turn and then reverses the process to pick up passengers, while N4 staff buses call at the central bus station and, at some periods of the day, at Queen’s Building.
Figure 1: London Heathrow Central Terminal Area ULTra network.
The Network
The network is shown in Figure 1 on the right. It has several stations in each of the Pink Elephant and Park 1 business car parks, and in the staff N4 car park, on the perimeter road north and northwest of the main Heathrow access tunnel. These are then connected by a guideway running through the access tunnel into a loop around the three airline Terminals of the CTA. The access tunnel has two full-height road lanes in each direction, but also a single lane on each side running in a sidebore which is too low for vehicles taller than cars or taxis. Each sidebore is wide enough to accommodate two ULTra guideways, and the lesser-used west sidebore is proposed for the system. It seems practicable to install the guideway at mezzanine level between departure and arrivals halls in all three Terminals, and if required to integrate some of the stations within the buildings, which it is planned to redevelop in conjunction with the opening of Terminal 5 in 2008.
Data on passenger demand to and from the car was obtained from BAA and from Atkins Planning, who are currently studying a number of redevelopment options for the CTA. Limited surveys were carried out of arrivals at the car parks to establish the shape of peak demand, and to measure passenger travel times on the shuttle buses: the journey times and waiting times assumed in the appraisal refer to relatively uncongested times of day, and are therefore favourable to the existing bus services.
The system studied has 7.6km of single-track guideway, and uses 78 vehicles to carry 8,300 passengers per day to and from the CTA. Since one guideway offers a capacity of 4800 seats per hour the system operates well below capacity. There are 24 at-grade stations in the car parks and one station per Terminal in the CTA, though these could be expanded at relatively little cost to bring passengers closer to their actual destinations, at their check-in desks, for example. Simulation of the system suggests an average waiting time of only 12 seconds.
Financial and Social Assessment
Although the existing shuttle bus system has low capital costs, its operating costs are estimated to exceed the ULTra operating costs, providing a Net Present Saving on operating costs over 30 years at a 6% discount rate of £12.5M (€19M). The PRT system provides both business passengers and staff with a much higher level of service, cutting in-vehicle times by an average of 4.4 minutes, walking times by 1.3 minutes and waiting times by 2.7 minutes. These passenger benefits have a 30-year Net Present Value of £88M (€132M), providing a total Net Present Value of £73M (€110M). Note that here, unlike the other case studies, there is no direct revenue, since passengers pay as part of their parking package. However, the large user benefits imply that, if necessary, passenger would be willing to pay more for the improved level of service.
Environmentally, the system will reduce the local air burden by 2.9 tonnes of carbon monoxide, 0.9 tonnes of hydrocarbons, 12.9 tonnes of oxides of nitrogen, and 1.7 tonnes of particulates. Although the absence of carbon dioxide emissions at the vehicle is compensated to some extent by emissions at the power station, there is a net saving of 311 tonnes of CO2 per year.
