chapter 11 buses guidelines for passenger transport in south africa a multi modal analysis

CHAPTER 11Buses

GUIDELINES FORPASSENGER TRANSPORT IN SOUTH AFRICA

A MULTI MODAL ANALYSIS

11.1 Introduction

• Most widely used form of public transport• Technical and operational characteristics– Most buses have two axles and a total of six wheels– Bus capacity, typically about 70– may vary between about 25 (midibus) and 125

spaces (articulated bus)– most common propulsion is by diesel motor– Electric propulsion from overhead wires (trolley

bus) is much less common

• vast majority of buses operate on streets, in mixed traffic

• increasing number of cities have reserved and separated bus lanes for heavily travelled routes– highest category is the busway, a roadway used

exclusively by buses.

11.2 General Characteristics of buses

a) Ability to operate on most streets– contain their own power plantAdvantages of buses over other public transport

modes – routes can be placed on any street as demand

requires – stops can be placed at many points.– Temporary reroutings are also relatively easy

• Disadvantages of buses over other public transport modes – ability of buses to mix with other traffic makes it

more difficult to separate buses where their operation would require such treatment than is the case with guided modes

– Because they “blend” with other traffic and their routes have no fixed facilities

– diesel buses have a weak identity and image.

b) Low investment cost– minimal route infrastructure makes rapid

introduction, changes, and extensions of bus routes and stops easy

– Also low permanence and usually little influence of (diesel) bus lines on land use and urban form

c) Moderate capacity – transport units (TUs) make buses the ideal mode

for lightly to moderately travelled public transport routes• services that require TUs with capacities of 15 to 60

spaces

– But when passenger volumes are high, buses become uneconomical because of their limited vehicle capacity

11.3.1 Classification by propulsion systems

• the diesel motor (diesel bus / motorbus), and electric motor (trolley bus).

(a) Diesel buses

• Superior characteristics: – ruggedness, – simplicity, – economical operation and – easy maintenance.

• Disadvantages:– exhaust, – vibration and – noise production.

• Note: Recent models have been produced which have greatly reduced negative effects: some of them meet rigorous air pollution standards, produce low noise levels, and have very little vibration.

(b) Trolley buses / Duo-buses

• Electrically powered vehicles which obtain power via trolley poles from two overhead wires (+ and -)

• excellent operating characteristics of electric traction: – rapid and smooth acceleration and deceleration, – no noise or exhaust fumes, – low vehicle maintenance costs and– high durability

• Disadvantages: – they require a higher investment and – line maintenance cost.

11.3.2 Classification by type of body

(a) Standard single-deck bus• The most common type of bus (and trolley bus)

is a single-deck body• two axles• six wheels• capacity of 50 - 60 seated passengers. • The allowance for standing passengers can vary

from 0 to 50 depending on circumstances.

(b) Articulated busArrticulated bus, compared with a standardbus, provides:+ Higher line capacity.+ Higher labour productivity (lower cost per space-km).+ Similar geometric movement characteristics. - Sometimes lower acceleration and climbing abilities

(depends on motor power). - Lower riding comfort, particularly in the rear section. - Somewhat lower stability at high speeds and/or in

sharp turns.

The main factors for their introduction are: 1. required capacity and 2. operating costs per space-km: • their inherent advantage over standard buses

in both of these makes articulated buses the best vehicles for heavily travelled routes.

(c) Double-decker busDouble-deckers, compared with standard buses, have:+ Higher capacity, particularly seating, for the same

vehicle length.+ An attractive view for passengers on the upper

deck.+ Little disturbance on the upper deck from

passenger movements, particularly useful for longer trips.

- Greater vehicle height, requiring higher clearances.

-Inconvenience of ascending and descending the stairway during bus movement.

- More difficult supervision of the upper deck (possible by driver via a periscope).

- More constrained passenger circulation, making doubledeckers less convenient for routes with heavy passenger turnover.

(d) Midibus• The midibus is a 5 to 7 metre long vehicle • total capacity of 20 to 35 passengers• no trolley buses of this type.• Note: In 1999, the South African Government

announced a large ‘recapitalisation” programme to replace minibus-taxis with midibuses. This programme, which involved an initial funding of R3,2 billion, (later raised to R8 billion) is discussed in the chapter on minibus-taxis.

11.4 Diesel Buses - Some Operational Issues

• Decline in market share (in terms of the journey-to-work) of the bus mode, from 12% to 9% between 1998 and 2003. Result– higher levels of traffic congestion, – longer journey times and – higher costs in general

• Factors that are relevant to the problem. They include:

1. The image of bus operations in general2. Environmental characteristics3. The poor organisational performance of bus

management

11.4.1 The image of bus operations in general

• communities that they serve take them for granted and regard them as part of the ‘street furniture”.

• The fact that they also operate virtually everywhere under category C conditions reduces their operational performance.

• In addition to the noise problem is the effect of gear changing, which is always accompanied by a change in engine pitch.

11.4.2 Environmental characteristics

• revving engines and • overpowering exhausts• other factors such as the presence of litter,

beggars and a lack of security

11.4.3 The poor organisational performance of bus management

• ineffectiveness of transport management • general lack of enthusiasm for promoting the

cause • for many years the bus industry has been a

target for subsidy cuts.– demoralised bus transport managers– lead to reductions in service and a tendency to

buy the cheapest vehicles or to rebuild older ones

11.5 Diesel bus developments and improvements

• Diesel bus manufacturers have raised quality standards.

• Many new developments have shaped the modern diesel bus. These have included:– modular concepts– combination of different materials– low-floor construction– improved shapes– more comfort features cont’

– driving position with better ergonomics– more safety features– new motive power solutions.

• Going modular has also made it easier to meet the requirements of different customers.

• Most buses and coaches are now characterised by innovative combinations of:– steel (which is now less than 50% by weight), – plastics (front and rear end, roof),– aluminium (doors) and other materials.

• Low-floor construction – originally for mothers with push chairs, elderly and

handicapped people. – also speeds up the loading and off-loading of

passengers, allowing operators of urban bus services to use fewer vehicles and drivers.

• Increased comfort– better seats and backrest support

• Ticketing and other passenger aids are now all within easy reach

• Information systems have been greatly improved

• Exhaust emissions have also been considerably reduced

11.6 Conclusion

• While technical improvements to diesel buses, such as quieter engines, automatic gears and other refinements are desirable, in themselves they will not solve the problems of the mode.

• Holistic approach is necessary – bus role within the hierarchy of modes transport modes.

• Better frequencies, many new routes and better marketing are also required.

• This study suggests that the presence of high-image modes in an integrated system will help to improve the image of the diesel bus component.

• The role of trolley buses and duo-buses should receive attention from planners and operators.

• This is an area which has been neglected up to now.