2.33
2.34
2.35
The double deck vehicle proposed for the upgraded tram system would be technically more advanced than any double decked vehicle previously built. It is a long, narrow vehicle into which would have to be packed a great deal of equipment, including air conditioning, with very limited space available under the floor. This in turn is likely to limit the number of doors that can be
provided.
A further practical point concerns boarding and alighting rates.
Calculations on the projected vehicle and the likely passenger
flows show that unless multiple unit operation is adopted, queues of trams would form at the main tram stops (especially in Central) due to the relatively low boarding/alighting rates. In part this stems from problems of internal circulation, but of much greater consequence are the difficulties of providing as many doors in relation to passenger capacity as on single deck cars. To the extent that dwell time is increased, journey times will rise, increasing the fleet necessary to satisfy a given passenger demand. Furthermore, long dwell times would give rise to delays as a result of vehicles queueing to get on to already occupied stops. Moreover, the variability of journey times would be increased as
a result of long dwell times and waiting to access stops, leading
to a less reliable service. A single deck Light Rail Vehicle,
which would be substantially longer than a double deck vehicle, provides facilities for a very high quality boarding/alighting
performance.
Despite the uncertainties of the double deck vehicle the Study
Team have concluded that if on-street operation were the only
consideration, it would be worth proceeding with the design of
such a vehicle. However if some tunnel operation is contemplated
and direct interchange with MTR is provided, then a single deck
vehicle is the preferred solution.
t
2.36
Two single deck Light Rail Vehicles have been introduced in the Study: a wide vehicle (Option C) and a narrower one (in Option D).
The issue of vehicle width is important because it affects
capacity, tunnel size and acceptability of on-street operation.
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