In this article we explain how more compact bus facilities can better fit within constrained city centre locations and make for improved integration of transport and land use, essential to supporting the economic, social and environmental objectives of developed and developing cities.
Increasing urbanisation is putting pressure on infrastructure in cities around the globe. In the developed world, competition for space to serve the transport needs of city centres is increasing, at the same time as governments are investing in more sustainable transport modes, such as walking, cycling and public transport modes like light rail and bus rapid transit. Another clear trend in many cities is increasing pedestrianisation, which is often achieved by reducing space allocated for vehicles.
In the developing world, increases in vehicle ownership are leading to worsening traffic congestion and declining mode share for sustainable transport modes.
In many cities, particularly smaller ones, buses will continue to perform a critical role in supporting the economic and social life of the city.
In the developed and developing world, buses must compete with private vehicles (often by providing enhanced services and facilities), in an environment with increasingly less space. However, some relatively simple public transport operational and management approaches can substantially reduce the amount of space required for bus terminals and interchanges and provide additional passenger benefits. Where this approach has been implemented, savings of space of greater than 50 percent have been achieved.
In this paper, we document the operational and management methods that can be used, as well as the benefits; and illustrate with a recent case study.
The main beneficiaries of more compact bus terminals and interchanges are public transport passengers and transport and city managers. The former benefit from reduced walking and transfer distances, better integration of facilities with their surroundings and increased safety, while the latter from a better use of space for a critical function, making bus facilities more compatible with other city sustainable transport goals.
However, there are also benefits for operators and managers of bus services, though compact interchanges require more intensive use of space, and some changes to conventional bus operations that may involve additional management.
Tradeoffs in ease of bus operations will result in improved integration of bus facilities with their surroundings, increased ridership and better durability. In a space-constrained location, a compact bus facility will be more compatible with integration into passenger destinations and less likely to be exiled to the edge or ‘back door’ of a city or town centre (due to lack of space, or if bus facilities are perceived as semi-industrial facilities).
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A people orientated approach
The guiding principle for this paper is that we are planning and designing for people, not for vehicles. Many bus terminals or interchanges appear to be designed primarily for the convenience of bus operations and vehicle movements.
The approaches discussed below aim to improve facilities for passengers and other people using or living with the facility.
So, what characteristics of bus operations (that we can influence) affect space requirements in terminals and interchanges?
The second-last item — passenger boarding time — is subject to things like fare and ticket policies and procedures, as well as bus design (number of doors and the like), which are often beyond the scope of a facility planner to influence substantially, so we will focus on the first three.
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Demand for bus space in interchanges and terminals is strongly influenced by bus schedules, particularly when buses are scheduled to arrive or depart at the same time, or within a few minutes of each other. Simply changing bus timetables to reduce the peaks of demand can reduce the overall space needed, but this approach will not be possible in all circumstances, such as in intermodal transport interchanges where the schedules of different modes are coordinated to improve passenger transfer times (such as buses scheduled to ‘meet’ particular trains).
Minor changes to bus schedules (such as shifting an arrival or departure times by even a few minutes) can substantially reduce peak bus space requirements and allow reorganisation of bus stops, or more efficient use of bus stops by sharing stops among several routes, with little to no inconvenience to passengers.
The potential impacts other locations on the bus routes (such as bus links to another transport node or interchange) must be taken into account, as well as the possible operating cost impacts of schedule changes.
The potential for schedule adjustments to reduce space can be limited where bus schedules are coordinated (because of the potential impact on interchange efficiency if this coordination is broken), where scheduled departures are at deliberate times (such as ‘memory’ or ‘clockface’ schedules which are beneficial to passengers), or when bus services are infrequent (frequent services are easiest to adjust because the impact on passengers is lower).
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A major component of dwell time in bus terminals and interchanges is bus layover for scheduled recovery time, or meal and other breaks that drivers need to take. Scheduled recovery layover time varies with route length, time of day and the like but is typically five to ten minutes, while meal and other breaks can be 30 to 60 minutes (though these are rarely scheduled in peak periods when demands for bus space are highest).
Typical bus stop turnover in terminals and interchanges, where layover parking is taken at passenger stops, can be six to ten buses per hour, with buses using stops for passenger drop off (typically 30 to 60 seconds), layover (typically five minutes) and passenger loading (up to three minutes).
Relocating the layover function can double bus stop turnover, (to 20 to 30 bus movements per hour), by increasing the potential for each stop to be used by more buses.
Layover parking can be relocated to a dedicated bus layover area (which can be on or off-street) as part of a transport interchange or terminal, or off-site.
In Christchurch New Zealand for example, bus layover was relocated from a central city location at conventional on-street bus stops on the edges of the CBD. In effect, the bus routes were extended through the city centre so that layover space needs would be in places with fewer space constraints (so that the central city terminal became a ‘through’ stop and the peripheral stops became the terminals).
While this approach may require buses to drive beyond the terminal or interchange, the impacts of this (additional operating costs and schedule impacts) can be reduced in two ways:
Bus stop assignment has a major impact on space requirements in terminals and interchanges. Conventional terminal and interchange planning which allocates each bus route its own stop, may maximise system legibility for passengers (who will always find their bus at the same stop), but can result in inefficient use of space (and reduced convenience and safety for passengers because of greater walking distances and more dispersed bus stops).
Planning for bus stops to be shared by routes with common destinations, or which service common geographic areas, can substantially reduce the overall size of the bus facility and improve utility for passengers. This may mean several bus routes making use of a single stop at different times, or bus stops with space for more than one bus to use them at the same time.
Space requirements can be further reduced by allowing for dependent (or nose-to-tail stops) rather than fully independent stops where bus stops need to accommodate multiple buses at the same time. With dependent stops, the first bus into the stop usually must depart first, to allow buses behind to leave.
Using dependent stops can save substantial space compared with fully independent stops, which allow for space for buses to pull into and out of stops independently of other buses. In a bus stop accommodating three buses at once (the practical limit of a single bus stop for passenger convenience) a dependent stop can save one bus length (up to 15 metres) of overall length.
Dynamic and semi-dynamic bus stop allocation systems, as used in Christchurch New Zealand and to be introduced to Perth’s Wellington Street Bus Station, can further reduce bus stop space in terminals and interchanges. In conjunction with real-time passenger information, dynamic stop allocation (where Intelligent Transport Systems track bus movements and monitor bus stop occupancy to match arriving and departing buses to vacant stops) can minimise the number of bus stops needed in a terminal or interchange, but relies on active management of the facility to sustain the more intensive operation. However, the benefits can be extensive, with potential for facilities’ space requirements being more than halved compared with requirements under conventional operations.
The most efficient bus stop allocation for a terminal or interchange requires a detailed understanding of bus schedules, route structure, and passenger needs, to ensure sufficient capacity, ability to accommodate late running without causing congestion, and passenger understanding of the transport system.