Annex A
TECHNOLOGIES AVAILABLE
A.1 The select Committee terms of reference
refer to light rapid transit systems (LRT). There is no universally
agreed definition as to what constitutes a light rapid transit
system, although a number of definitions have been proposed. However
the use of the term "light" is intended to differentiate
such systems from conventional higher capacity heavy rail systems
(including both main line and underground/metro systems). Similarly
the term "rapid" implies a service which provides significantly
shorter journey times than alternatives such as conventional bus.
LIGHT RAIL
A.2. The term "light rapid transit
systems" is most widely used to describe modes of transport
otherwise described as light rail or tram systems. There are some
300 such systems worldwide, including seven in the UK.
A.3 Modern light rail systems in the UK
are:
Tyne and Wear Metro (opened 1980
and extended 1991);
Docklands Light Railway (opened 1987
and extended in 1991 and 1994, extension to Lewisham due to open
2000);
Manchester Metrolink (opened 1992,
extension to Eccles due to open 2000);
Sheffield Supertram (opened 1994);
Midland Metro (opened 1999);
Croydon Tramlink (due to open late
1999).
A.4 In addition there is the Blackpool Tramway,
the sole survivor of the earlier generation of tram systems.
A.5 These systems exhibit a range of technical
characteristics. The Tyne and Wear and Docklands systems are both
fully segregated from pedestrians and road vehicles. The other
system, have long lengths which are similarly segregated, but
run on street either in dedicated lanes or with other traffic
elsewhere. The Docklands system is controlled automatically and
there are no drivers (in normal operation). On vehicle staff are
used on fare collection and customer care duties. The other systems
are all driver operatedpredominantly driven on "line-of-sight",
but the segregated sections of Manchester Metrolink are controlled
by conventional railway signalling.
A.6 In addition to the systems listed above,
a number of other towns and cities have considered the introduction
of light rail systems. Schemes which have gained authorisation
by means of Act of Parliament or a Transport and Works Order,
but have not yet been implemented include Leeds and Nottingham
and extensions to the systems in Tyne and Wear, West Midlands,
Manchester and Docklands. Award of a concession for the construction
and operation of the Nottingham system is expected very soon.
A.7 Light rail systems are expensive. The
cost (including route infrastructure, central facilities and rolling
stock) is typically £5-10 million per route km for at grade
systems. Systems with significant lengths of elevated or underground
routes are significantly more expensive.
A.8 In many European cities light rail systems
have been funded publicly, with no great requirement to demonstrate
value for money. In the UK context such schemes have to meet strict
economic and financial criteria, and as a consequence many schemes
which have been put forward are unlikely to viable under current
criteria.
INTERMEDIATE MODES
A.9 Recognition of the current position
has led a number of local authorities and passenger transport
executives to consider lower cost alternatives to light rail systems.
The aim is to provide most of the high quality aspects of light
rail systems, and hence to attract similar levels of patronage,
whilst reducing the cost. A range of potential technologies have
evolved to fill the gap between conventional bus and full light
rail. One approach has sought to reduce the cost of light rail
by an innovative approach to vehicle and track design. However
most seek to dispense with the fixed steel rails and use rubber
tyred vehicles with some form of guidance for all or part of the
route. Such systems are known collectively as Intermediate Modes.
Kerb Guided Bus
A.10 Kerb guidance can be fitted to any
conventional bus, and comprises small rubber guide wheels which
run on vertical upstands on either side of the route and steer
the standard vehicle steering system. Systems have been operating
in Essen and Mannheim in Germany and in Adelaide in Australia
for a number of years. In the UK a trial length of kerb guidance
operated in Birmingham from 1984-87. A short length of kerb guidance
has been introduced in Kesgrave, Ipswich between two separate
residential estates, as part of a wider quality bus initiative.
In Leeds kerb guidance has been introduced in Scott Hall Road
on a radial corridor to the north of the city. Kerb guided bus
systems are planned for Edinburgh, Leigh (in Greater Manchester),
Chester and the York Road corridor in Leeds.
A.11 As the guidance system relies on upstands
either side of the route, kerb guidance can only be provided on
segregated section of route. Elsewhere the bus has to be manually
steered. Special entry sections are required at the beginning
of guided lengths, and these may impose a speed restriction at
these points on higher speed systems, although short gaps in straight
lengths can be crossed at full speed. The Essen and Adelaide systems
have long lengths of segregated operations. By contrast, the Leeds
system utilises guidance only to pass the more congested parts
of the road network, and the Ipswich system is essentially a self
enforcing bus-only "gate" between two residential estates.
Electronic Guided Bus
A.12 This system can also be fitted to any
conventional bus. A pair of wires carrying an electronic signal
is laid in the road surface. An antenna mounted under the front
of the vehicle picks up the signal and an on-board computer controls
the steering to follow the route of the wires. This system is
in operation on specially built vehicles in the service tunnel
of the Channel Tunnel. A demonstration system was successfully
trialled in Newcastle. This technology was selected for the Merseyside
Rapid Transit System. The first application in service will be
the Millennium Transit linking Charlton Station to the Millennium
Dome at Greenwich, due to open later this year.
A.13 The system can operate on segregated
and shared alignments. Vehicles can be manually steered when not
on the guided section, and it is possible for vehicles to enter
or leave guidance at any point. Two sets of wires carrying different
frequency signals and following diverging routes can be used to
provide the equivalent of railway "points".
Guided Light Transit
A.14 Guided Light Transit (GLT) has a central
rail laid flush with the road surface which is followed by a double
flanged wheel which operates the vehicle steering system. A prototype
has operated in Rochefort in Belgium for a number of years and
the system has also been trialled in Paris. The system has been
selected for Caen and Nancy in France.
A.15 The system can operate on segregated
and shared alignments, but entry to guided sections can only be
made at special depressed "funnels", which must be located
on segregated sections and traversed at low speed.
Automated People Mover Systems, Monorails, Maglev
Systems
A.16 There are a number of people mover
systems, usually fully automated and which require special fully
segregated track. These are used over relatively short distances
at locations such as airports, shopping centres and theme parks.
They are not appropriate for urban transport and are not considered
further here.
Attributes of Intermediate Modes
A.17 The overall attributes and characteristics
of intermediate mode systems can vary widely. They can loosely
be divided into two categories: bus up and tram down.
Bus up schemes are essentially conventional bus with a
number of enhanced features. These are likely to be relatively
low cost options, but may suffer many of the disadvantages of
conventional bus operation. Tram down schemes aim to preserve
as many as possible of the successful attributes of light rail
systems, but with reduced cost. In this context the Leeds and
Ipswich kerb guided bus systems, and the Millennium Transit are
bus up whereas the GLT and Merseyside Rapid Transit are
tram down.
A.18 Features which move a system image
closer to that of the tram are:
high quality vehicle with distinctive
(non-bus) image;
quality stops with low-delay step-free
boarding, clean modern shelters, and good passenger information;
stops located to serve key destinations
and interchange points (including park and ride where appropriate);
regular, reliable, high frequency
service, with fast journey time;
a high degree of segregation and/or
effective priority over other traffic to minimise journey times;
a high degree of segregation and/or
effective priority over other traffic to minimise journey times;
smooth ride, low noise, environmentally
friendly traction (electric or "clean" fuel);
significant lengths of guidance.
Getting the Right Attributes
A.19 In principle any or all of these attributes
can be applied to any of the systems described above. The overall
combination of the right attributes is more likely to result in
a successful outcome than the application of a particular system
selected purely on the basis of its technology.
A.20 Where rapid transit is to be implemented
by upgrading existing bus systems the bus up approach is
often appropriate. Bus priorities and short lengths of kerb guidance
can be introduced at key locations, together with a modest upgrade
of stops and vehicles, together with the introduction of system
branding and marketing. This was the approach in Leeds, where
it has shown a significant increase in patronage and mode transfer
from cars.
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