Bus rapid transitFirst principles assessment Why introduce Guided Bus? Demand Impacts Supply Impacts Financing requirements Expected Impact on Key Policy Objectives Contribution to Objectives Expected impact on problems Contribution to Alleviation of Key Problems Expected Winners and Losers Barriers to Implementation Bus Rapid Transit is intended to improve the image of public transport bus services by improving the quality of public transport provided. It attempts to accomplish this through a package of measures including the provision of partial or wholly dedicated running lanes, attractive bus interchange designs and stops, using buses that are comfortable and have a distinctive livery that are provided frequently. In addition, a wide variety of transport telematics (e.g. signal priority for buses) and off board fare collection are used to reduce the journey time for the bus journey. These measures are combined such that the capacity and the quality of service approaches that of rail based systems but at a capital cost that is usually much lower than that of constructing a brand new rail system (Wright and Hook, 2007). One specific way BRT systems achieve their journey time savings is through the provision of dedicated busways using guidance systems. Guided Buses provide increased opportunities to implement dedicated busways where road space is in short supply and, hence, where conventional bus lanes could be impractical. This means that they are particularly well-suited to congested conditions, as they represent a means of increasing bus speeds and reliability for the minimum loss of road space to other vehicles. Two further reasons for implementing kerb guided bus systems, specifically, are that they provide opportunities to improve physical access to the bus by minimising the vertical and horizontal gaps between the bus and the kerb at the bus stop and that the physical segregation from other traffic provided by the kerbs means that it is impossible for other vehicles to block the guideway. In this way, kerb guided bus systems are 'self-enforcing', as opposed to interventions such as bus lanes Bus Priority and street running light rail which require some degree of police enforcement in order to protect the rights of way for the vehicles for which they are intended. They also provide for considerable flexibility in operations, in that a suitably adapted bus can travel on a guideway where this is available but can also travel on any other part of the road network as required. This means that, in contrast to light rail, distributed access to the guided bus corridor can be provided easily in outer suburbs using the same vehicles. They are also very flexible in that guidance need only be provided where and when traffic conditions deem it appropriate. For example, guideways may be constructed at particular congestion 'hot spots' to allow suitably equipped buses to enter the guideway, advance to the front of a traffic queue, and then leave the guideway to re-enter the main traffic stream. This allows for incremental implementation, whereby self-contained, perhaps relatively short, sections of guideway may be constructed ready for use by suitably equipped vehicles straight away, rather than having to wait for a network of guideways to be constructed. This means that benefits can start occurring early on in the process. It also means that, as congestion becomes worse, or as it changes its location, new sections of guideway may be added relatively easily. Demand impactsThe BRT system is intended to provide a high quality public transport alternative to car travel so they are likely to impact on the demand for travel by car, as people switch from car to guided bus, and by other forms of public transport, as people switch from lower quality public transport services to BRT. The attraction of public transport users from other, lower quality public transport on that, or other, corridors may, however, detract from the viability of those other services and result in a reduction in their supply. The extent to which BRT will draw its demand from car as opposed to from lower quality public transport services will depend on whether BRT is viewed as being on a par with existing bus services or more closely related to a rail service. This is an important question but one on which the answer is not yet clear. The increased physical accessibility of BRT systems and kerb guided bus systems will provide new travel opportunities for people who have difficulties with conventional bus services (e.g., older people, disabled people, parents with buggies etc). These public transport quality enhancements are also likely to generate new public transport journeys. Hence, BRT will not only impact on the demand for car travel and the demand for other public transport travel, but will impact on the total demand for travel within the area.
Short and Long Run Demand Responses
Bus Rapid Transit Systems have the effect of reallocating road space from general traffic to bus traffic at particular points in or along particular stretches of the road network. However, in order to provide additional priority to the buses, certain roads may become bus only streets along the routes of the network. A guided bus service will tend to replace, or represent an enhancement to, existing bus services along the corridor in question. So again in this sense they do not necessarily increase the supply of buses within the affected corridor. However, by freeing up buses and their drivers from delay due to congested traffic conditions, they allow for a more efficient use of the bus fleet and driving crew. These efficiencies may then be passed on to the travelling public in the form of cost savings or service improvements, eg increased service frequencies along the route (or along other routes via redeployment of buses and drivers); alternatively, the efficiencies may be recycled within the bus operating company, eg in the form of higher wages. Another way in which kerb guided bus systems affect supply is via their provision of step-free access on to and off the bus. In doing this, they increase the share of physically accessible public transport services within an area and, hence, change the nature of the public transport network. Bus rapid transit systems in general, and guided bus systems in particular, will tend to be considerably less expensive, in terms of capital costs, than rail-based systems, though operating costs for bus-based and rail based systems will tend to be relatively similar. A US study showed that the capital cost of constructing dedicated busways ranged from 7m dollars per mile to 55m dollars per mile, with an average cost of approximately 13m dollars per mile (General Accounting Office, 2001). Remembering that guideways will typically only be provided at certain key points along a bus route, a guideway can have a relatively significant impact at a relatively low cost. For example, some projects involve guideways along less than 10% of the bus route. For comparison, the same study showed an average cost for constructing a light rail line of 34m dollars per mile. In contrast with guided bus, a light rail line must be provided for the full length of the route.
The diversion of car journeys to guided bus will contribute to economic efficiency, environmental and, to a lesser extent, safety objectives, whilst the new travel opportunities will contribute towards accessibility-related objectives and towards economic growth. The attraction of public transport users from other, lower quality services will represent benefits for those people switching, but any reduction in the supply of those other services will, at least partially, offset these benefits and may detract from accessibility-related objectives and economic growth. Whilst guided bus systems are likely to have positive equity implications, since they offer a service which can be used by all, these benefits are limited to the corridors directly served, and any corresponding reduction in bus services may disadvantage certain groups of travellers. The positive impacts of guided bus systems depend critically on their ability to attract patronage. As noted above, if guided bus is perceived by car users as a slightly improved bus it will be unlikely to contribute significantly to key objectives and will perform much as bus priority measures do Bus Priority. If it is seen as a higher quality service approaching that of rail, its impact will be much greater.
Expected impact on problems Where they attract car-users, BRT systems have considerable potential to contribute to the alleviation of congestion-related and environmental problems; where they re-allocate road space away from the car there may also be some adverse impacts on congestion, though these should be less than in the case of light rail which requires more road space than does BRT. In addition, there may be some adverse impacts on community severance unless stringent efforts are made to assist people to cross the guideway, e.g. via the use of pedestrian controlled crossing facilities. Again, impacts will depend on the extent to which it is perceived as a slightly improved bus or as a higher quality service approaching that of rail.
Expected Winners and Losers
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