Guided bus systems evidence on performance

Evidence on performance
The Adelaide O-Bahn
Leeds Superbus – A61 (Scott Hall Road)

Empirical evidence of the impacts of guided bus systems comes principally from Australia, Germany and Britain. this is further supplemented by anecdotal evidence from other existing and planned systems in France and the US.The first kerb guided bus system in the world was introduced in 1980 in Essen, Germany. Then, in 1984 a system was introduced in Birmingham, England, though this closed in 1987 in the wake of British bus deregulation. In 1986 a system was introduced in Adelaide, Australia, in 1992 a small system was introduced in Mannheim, Germany and in 1995 systems opened in Ipswich and Leeds, England. A second system opened in Leeds in 2001 and, most recently in 2002, a system opened in Bradford, England.

The Adelaide O-Bahn

Context

The O-Bahn in Adelaid was opened in 1986 and is the world’s longest guided busway. It traces a 12km north-easterly route from 3km north of the centre of Adelaide out to a major regional shopping center at Modbury, 15 km from the city center. It is grade Separated from the road system and has only two intermediate stations so as to minimize travel time. Both intermediate stations are at locations where the corridor intersects major cross-town roads: at Paradise (9km from the city) and at Klemzig (6 km from the city [figure?]. Park-and-ride [link to ‘park and ride’] facilities, with total parking for approximately 1000 cars, are provided at Modbury, Paradise and Klemzig. The system was opened in two stages, the first of which - between the city boundary and Paradise - commenced public operation in March 1986, with the full system then opening in August 1989.

Buses start their inbound journey at a suburban terminus, spend approximately a third of their journey on suburban streets, join the O-Bahn at either Modbury or Paradise for travel to the edge of the city; buses then leave the guideway and continue the 3km into the city centre along public roads, on which bus priority is provided. The O-Bahn group of services are privately operated under contract to the government by a single franchisee.

For more information see http://www.adelaidemetro.com.au/guides/obahn.html

Impacts on demand

Overall travel, journey length and destination

Before-and-after surveys, undertaken in 1985 and 1991, indicated that weekday public transport patronage in the O-Bahn corridor rose by 8.5 percent immediately following opening of the first stage and rose a further 9.4 percent immediately following opening of the second stage. In total, patronage increased by 22.2 percent over that whole period. it is estimated that, in 1991, public transport patronage on bus services in the O-Bahn service area were 50 percent higher than would have been the case without the O-Bahn.

Patronage on bus services using the O-Bahn remained broadly constant between 1991 and 1998, whilst patronage on the remainder of Adelaide’s public transport system over this period has declined. In 1998 there were approximately 20,000 passenger trips on the 0-Bahn each weekday and it was estimated that about 20 percent of passenger trips on the O-Bahn use one of the three park and ride facilities.

Choice of mode

The final After survey, in 1991, indicated that 14 percent of users of the O-Bahn had previously been car drivers and 5 percent had been car passengers. The same survey indicated that 65 percent of O-Bahn users had previously been bus users, and 10 percent were new trips.

Time of travel No impact recorded

Route

The final After survey, in 1991, indicated that 6 percent of users of the O-Bahn had transferred from bus services in neighboring areas.

Impacts on supply

Several bus routes enter the busway at Modbury and at Paradise. Average peak period headway between the Paradise interchange and the city is approximately 50-s, whilst in the daytime off-peak, a five minute headway is operated on the busway, with feeder buses serving the Modbury and Paradise interchanges on routes with less traffic. Headways during the late evening and weekends range between 12 and 15 mins, during which time extensive use is made of feeder services. Most services stop at both Paradise and Klemzig, though some services operate express.

Buses using the O-Bahn have travel times around 10 mins faster than when they used the arterial road system (on which considerable bus priority [link to ‘bus priority’] had been provided). Travel time between Modbury and the city is 22 mins on stopping services and 20 mins on express services. The bus fleet using the O-Bahn comprises approximately 110 buses, half of which are articulated.

Importantly, the O-Bahn represented a significant increase in public transport capacity within Adelaide. It is thought that the capacity of the O-Bahn is unlikely to ever be a constraint, as it has been estimated that with a 20-s headway and use of articulated vehicles an hourly capacity of 18,000 passengers in each direction could be provided.

Contribution to objectives

Objective	Scale of contribution	Comment
		The reduction in bus journey time and increases in bus patronage and capacity demonstrate an efficiency improvement in the operation of the bus service. Also, a significant transfer from private car to public transport has been observed. However, no comprehensive cost benefit analysis was conducted.
		Much of the busway is ‘off-street’, nevertheless the route has been developed with a visually prominent environment with large forest trees, increased bird life, and a system of pedestrian and bicycle trails, resulting in an attractive corridor. In addition, traffic on local streets willhave decreased slightly.
		No specific assessment of environmental impact, though it is likely that there will have been some benefits in terms of the transfer from private car to public transport
		Any improvement to public transport will tend to benefit lower income travellers as they tend to have a higher propensity to use public transport
		This was not a key objective and no attempt was made to assess impacts. However, there have only been two accidents on the facility and no incidents for almost a decade.
		No specific assessment has been made but, by increasing the capacity of the corridor and facilitating more movement of people into the city centre, it might be expected that it has had a minor positive impact on city centre viability, as well as perhaps helping to develop Modbury as a suburban centre.
		The total cost of providing the O-Bahn was estimated as 63mn USD (in 1988 prices), two thirds of the cost of providing a comparable LRT system (all costs include allowances for rolling stock, physical contingencies, and design and supervision but exclude land acquisition) *. Operating costs are, on average, broadly similar to those for standard bus services.

	= Weakest possible positive contribution,		= strongest possible positive contribution
	= Weakest possible negative contribution		= strongest possible negative contribution

= No contribution

* Readers are cautioned against using the cost of the O-Bahn as a guide to the cost of constructing a guided busway in other circumstances. Three factors, in particular, increased the cost of the project

(1) the highly expansive clay soil in the corridor;

(2) the large number of bridges resulting from location of the busway in a river corridor; and

(3) the development of a linear park together with the O-Bahn project.

Leeds Superbus – A61 (Scott Hall Road)

Context

The guided bus system on Scott Hall Road in Leeds, branded as Superbus, was launched in 1995. Scott Hall Road is a well-defined, radial corridor of dual carriageway status to the north of the city. Bus was not traditionally regarded as a significant mode along the corridor. In contrast with the O-Bahn in Adelaide which uses a continuous guideway along a wholly separate right of way, the Leeds scheme uses a series of relatively short stretches of guideway on or immediately adjacent to an existing road at particular points where traffic congestion occurs. The guideway was completed and opened in sections, the first of which opened for operation in September 1995 and the third and most recent of which opened in 1998.

Impacts on demand

Overall travel, journey length and destination

The operator has recorded increases in patronage of over 75% and 50% reductions in peak journey time since the opening of the first section of the guideway in 1995 (Dark, 2001; and Bain, 2002), whilst patronage on other services has been in decline. However, only around 6% of passengers reported using the bus as a result of the guided bus facility. It appears that others have been prompted to do so when changing job or home (Daugherty and Balcombe, 1999).

Choice of mode

The operator estimates that between 10% and 20% of new passengers have shifted from car (Bain, 2002) and that this equates to approximately 500 car drivers per week (Firstgroup, 2000).

Daugherty and Balcombe found little direct evidence of a reduction in car use (Daugherty and Balcombe, 1999), but it may well be that those using the bus after changing job or home would previously have travelled by car.

Time of travel No impact recorded

Route

There is some anecdotal evidence to suggest that some passengers have diverted to the guided bus service on Scott Hall Road from nearby parallel bus corridors, perhaps abstracting from patronage on those parallel routes.

Impacts on supply

It has been estimated that travel times were reduced by an average of 70 seconds over a 4km length, but some buses were faster than cars over the route. Furthermore, variability in bus journey times fell by 75% (Daugherty and Balcombe, 1999).

In addition to the guideway itself, the scheme included new state of the art accessible vehicles for operation of the service, special ‘tailor-made’ information at stops, new shelters and a park and ride site towards the outer end of the route. Furthermore, in response to the increased patronage and reduced journey times experienced since the opening of the scheme, the operator has introduced a revised timetable with more frequent buses. Only minor adjustments were made to the vehicular capacity of the road, as guideway was only installed along a limited number of key sections of the route and some of these run along the central reservation. However, in contrast to the O-Bahn in Adelaide where the guideway represented an increase in public transport capacity without any reduction in road capacity for other traffic, the Leeds scheme has involved a slight reduction in road capacity for other traffic.

Contribution to objectives

Objective	Scale of contribution	Comment
		The reduction in bus journey time and increase in bus patronage demonstrate an efficiency improvement in the operation of the bus service. However, no comprehensive cost benefit analysis was conducted.
		The guideways have been accused of being unattractive – sometimes replacing former green space - and presenting a barrier to lateral movements.
		No explicit assessment has been undertaken but it is expected that the impact willhave been minor
		The up-grading of the service incorporated new, accessible vehicles with level boarding at bus stops; making the service accessible to disabled people and parents with prams. Furthermore, any improvement to public transport will tend to benefit lower income travellers as they tend to have a higher propensity to use public transport
		This was not a key objective and no attempt was made to assess impacts. However, the guideway tends to be associated with higher levels of safety by virtue of it segregating the bus from the rest of the traffic.
		No specific assessment has been made but, by increasing the capacity of the corridor and facilitating more movement of people into the city centre, it might be expected that it has had a minor positive impact on city centre viability.
		The total capital cost of the scheme was approximately £4m, with an average cost of around £1.5m per route km. *

	= Weakest possible positive contribution,		= strongest possible positive contribution
	= Weakest possible negative contribution		= strongest possible negative contribution

= No contribution

The financing was via a Public Private Partnership (PPP) which involved First Leeds (the bus operator) who provided the new, high quality accessible guide-wheel equipped vehicles, Leeds City Council (the local highway authority) who provided the guideway and associated bus priority measures and Metro (the local public transport planning authority) who provided information, new shelters and stops.

Text edited at the Institute for Transport Studies, University of Leeds, Leeds LS2 9JT