Transport network optimisation

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3. International directions

• 3.1   Land use and transport planning integration
• 3.2   Attitudinal and behavioural measures
• 3.3   Optimising traffic operations
• 3.4   Public transport
• 3.5   Walking and cycling
• 3.6   Freight
• 3.7   Pricing and charging measures

Many techniques have been tried overseas to help optimise the transport system and its networks. Information in this section comes from an extensive international literature review of research and published papers and advice from the international panel. For the purposes of this project, these techniques have been grouped into seven categories, although there is some overlap amongst the categories.

3.1   Land use and transport planning integration

Land use has an important relationship with the transportation system. Good towns and cities with effective transportation systems require more accessible land use patterns and more multi-modal transport options, to reduce the amount of travel needed to reach activities and to give residents viable mobility options. A more diverse transportation system can provide many benefits by letting travellers choose the most efficient and appropriate option for each trip. Optimal transport systems result in each mode being used for what it does best, from an individual as well as a societal perspective.

Policies need to be developed to combat urban sprawl. In larger cities, land use policy- and decision-makers should encourage higher urban population densities and centralisation of the population and activities around passenger transport hubs. Higher densities give more people more potential destinations and activities within walking and cycling distance and make public transport more accessible. As patronage goes up, bus and train frequencies can increase, improving the level of service for public transport users and further improving patronage levels. Success breeds success!

But mixed use development is perhaps also as important as intensification and higher densities. Mixed use development allows people to find jobs, recreational opportunities and goods and services close to their homes, reducing travel demand and increasing the feasibility of travelling by more sustainable modes.

Smart growth is an urban planning and transportation theory that concentrates growth in the centre of a city to avoid urban sprawl. It advocates compact, transit-oriented, walkable, bicycle-friendly land use, including neighbourhood schools, streets that work for everyone and mixed-use development with a range of housing choices. “New urbanism” is a similar concept with its roots in architecture and urban design.

Smart growth values long-range, regional considerations of sustainability over a short-term focus. Its goals are to achieve a unique sense of community and place; expand the range of transportation, employment and housing choices; equitably distribute the costs and benefits of development; preserve and enhance natural and cultural resources; and promote public health.

Changing from minimum parking standards for new developments to maximum standards can reduce the amount of space devoted to parking (and increasing urban densities) while reducing the attractiveness of driving. Such practices often need to be introduced at a regional level to ensure consistency and to prevent one council compromising its parking policies and standards to attract inappropriate, low-density development at the expense of a neighbouring council.

Often the development of transport policies involves parties external to the transport sector. Government intervention will be required to achieve an altruistic outcome and multi-disciplinary, international teams can often add value to the development of policies. Citizen involvement is seen as essential in policy development.

3.2   Attitudinal and behavioural measures

A number of interventions are available to influence travel behaviour and travel demand. These include individualised marketing to reduce car use (often targeted at the workplace, household or community level), where travel planners visit willing businesses, individuals or households and develop options with them that may include assessing public transport and cycling options and supporting them as they make lifestyle changes. Some people may even consider moving house or changing job location to reduce total travel, with more time to do other more important things than travelling.

School and workplace travel plans are somewhat labour-intensive but effective interventions to influence travel demand and reduce motor vehicle use. Ride sharing has been promoted particularly through workplaces and can provide some reduction in single-occupant motor vehicle trip-making. These interventions do need to be supported over time; left alone they often become less effective as people lapse into earlier patterns. Ride sharing, for example, can diminish over time as key people in an organisation leave to work elsewhere.

Travel demand management (TDM, also called “mobility management”) is a term used to encompass a range of strategies that result in a more efficient use of transportation resources. These strategies generally involve changes in policy emphasis to maximise the capacity of existing roads and minimise travel, especially by private motor vehicle. For example, parking policies may evolve from the provision of parking spaces to the development of workplace travel plans and integrated transport assessments (plans detailing how the traffic requirements of a site will be met using a variety of modes).

TDM proponents note that accessibility (rather than mobility) should be the focus of optimisation processes and that planning should be truly multi-modal, as, when all impacts are taken into account and proper land use planning is applied, private motor vehicle use is less efficient than its alternatives. It has been said that “beyond an optimum level, increased mobility is harmful to consumers because it wastes resources – time, money, land and energy – with more beneficial alternative uses.”

Car clubs allow urban residents to share ownership and other fixed costs of cars, with booking schemes that allow them to pay for cars when they need them. They may then not need to own a car (or a second car). This results in reduced motoring costs for individuals and families and generally reduces total travel by those involved. Car clubs are increasingly common in Europe and North America.

Car clubs allow urban residents to share ownership and other fixed costs of cars, with booking schemes that allow them to pay for cars when they need them. They may then not need to own a car (or a second car). This results in reduced motoring costs for individuals and families and generally reduces total travel by those involved. Car clubs are increasingly common in Europe and North America.

Transport policies are often used to influence travel behaviour. Network optimisation relies partially on changing society’s habits, for example by encouraging less use of private motor vehicles. There are also merits in looking at human needs such as accessibility to influence the function of the transportation system.

3.3   Optimising traffic operations

Traffic operations are at the core of network optimisation, traffic congestion management and road safety. This includes how individual intersections are managed (and the form of intersection control, such as roundabouts, traffic signals, and Stop and Give Way controls). New Zealand has many practitioners who devote their careers to the “coal face” of traffic operations. Conferences (such as the IPENZ transportation Conference) concentrate on the art and science of optimising traffic operations.

However, the focus of traffic operations practitioners is changing from designing new facilities to managing existing infrastructure better. This means ensuring all roads and intersections are designed to better accommodate pedestrians, cyclists and public transport vehicles.

The concept of a hierarchy of users has been established in the UK for use in traffic planning and design processes. This hierarchy places pedestrians at the top, followed by cyclists, then public transport, then freight, with unaccompanied private car-users last. The objective of such a hierarchy is to ensure that the needs of the most vulnerable and most sustainable road users are fully considered in all schemes, but not necessarily to give priority to pedestrians and cyclists in every location.

Adoption of a hierarchy of users is recommended as one of the elements of good practice in the UK’s Local Transport Plans, and is one of the recommendations in the UK Government's Response to the Select Committee on Walking in Towns and Cities.

Intelligent transportation systems (ITS) provides ways in which technology can help improve traffic operations. ITS comes in many different forms. It can be divided into three categories: driver assistance systems, traveller information systems and traffic management systems. Systems that assist drivers of private motor vehicles can include devices that control speed, starting and stopping and lane positioning; these improve the efficiency and safety of individual vehicles and therefore improve the capacity of a network.

Providing information to motorists and empowering them to make decisions based on real-time information can improve the operation of a network. Variable message signs can improve the operation of a network by encouraging drivers to divert to less congested routes, although researchers found that, due to driver behaviour, the benefits were never distributed equally throughout the networks studied. Furthermore, improved real-time knowledge by drivers of traffic conditions on a network may simply allow more users to use the system at peak times, effectively “filling up” more roads to ever higher levels of congestion.

ITS can also be used to improve road pricing operations to help eliminate “pinch-points” in the transportation system and therefore increase its overall capacity. Various technologies are available such as automatic number plate recognition systems, electronic vehicle identification, open road tolling, multi-lane free flow and infra-red vehicle occupancy counters used in the implementation and enforcement of charging systems. ITS is very context sensitive and different systems are not necessarily interchangeable between locations. Research, monitoring and development are required to effectively implement ITS measures.

“Smart growth”, “new urbanism” and traffic calming support modifications to conventional urban road design standards to allow narrower roadways and to reduce traffic speeds. Streets can become more conducive to use by pedestrians and cyclists. Streets should be considered to be part of the open space resource of a town or city and available for passive enjoyment. Many streets are so clogged with traffic that they are unpleasant places for these purposes. Implementation of these practices requires technical and political leadership with the courage to challenge existing guidelines and standards, and to rewrite these over time.

Parking management is also a useful component of network optimisation. This includes on-street management, where parking may need to be removed in some locations to provide space for pedestrians, cyclists or public transport, or to help manage motor vehicle travel demand. But off-street parking supply management is also needed to manage travel demand.

3.4   Public transport

Increasing public transport use improves the capacity of a road network (as buses and trains take up less space per person than private motor vehicles) and is more environmentally sustainable. However, public transport is often seen by potential users as less desirable than car travel so public transport systems have to be carefully designed, managed and promoted to attract and sustain patronage. Road space may need to be reallocated to favour public transport over other motor vehicles.

Many new technologies and methods are being developed to improve public transport services. Flexible transport systems which offer non-conventional, demand-responsive passenger transport options are also emerging. Integrated ticketing systems allow passengers to transfer between public transport services of different modes and different providers while still using the same payment methods. The introduction of an integrated ticketing system to The Netherlands’ has been shown to provide a wide range of socioeconomic benefits which exceeds the total cost of implementation.

Planners and decision makers are beginning to apply forward planning to public transport projects, for bus rapid transit systems could be designed in anticipation that they would later be converted into light rail transit systems. The efficiency of a railway system can depend on specific regulations which determine whether the focus of the system is passenger or freight transport. The recent decision to buy back the New Zealand rail network into public ownership should help improve co-ordination and implementation of urban rail initiatives.

Improving public transport may require large investments, especially for rail systems. Such investment is most successful when the providers and users are supportive of public transport. Investing in passenger rail usually encourages more intense land development, particularly around the stations, but also along the corridors. Accordingly, such investment decisions should be based on sound land use and transport planning so that development occurs in appropriate places.

A variety of complementary policies and programmes can increase the cost effectiveness of such investments by encouraging ridership and improving operating efficiency. Examples include public transport priority in traffic management, road and parking pricing, public transport oriented development, and improved conditions for walking and cycling around public transport terminals and stations.

Transport policies regulate other elements of the transport system; it has been suggested that the optimal strategies would be those involving higher toll charges and increased public transport frequencies.

For large overseas cities, a decentralisation of population and activity locations is expected to occur. Cities will move from being mono-centric to poly-centric, with their centres based around passenger transport hubs. The lesson learnt from previous public rapid transit systems is that it is important to invest in rail but major controlling actions (zoning and road pricing) are required to induce supportive changes in land use.

New Zealand may be able to position itself more competitively in the global market by having smaller cities where walking, cycling and buses provide ample travel choice without the need for much more expensive light or heavy rail systems. Auckland is of such a geographic size and elongated shape that rail is necessary, and Wellington is fortunate in already having significant rail infrastructure. Other cities may, however, be much better placed with the cheaper and more flexible option of buses, supplemented by comprehensive efforts to support walking and cycling. Buses can be more heavily subsidised in central or heavily congested areas to induce mode shift away from car travel.

Accurate data collection and analysis are important when planning public transportation services. Data collected from automatic fare collection systems on public transport services can be analysed so that planners can adapt the services to suit passengers’ journey needs.

3.5   Walking and cycling

Walking is important as the original sustainable transport mode. The concept of “walkability” is used to describe the ease with which it is possible to walk in a particular area or city. Walkability is important, not just for people making walking trips, but also as a way for motorists to travel between parking areas and origins and destinations and for bus and train users to access public transport stops and stations.

People walking (or “pedestrians”), in a transportation planning sense, includes a wide variety of people. Those using mobility aids, those with vision impairments and those of limited cognitive ability (including younger children) are all pedestrians and users of walking facilities. Provision and continued maintenance of footpaths, tracks and road crossing facilities are essential for pedestrians. Many other design, infrastructure, information, encouragement and policy provisions can be made to enhance footpaths. But there is more to making towns and cities more walkable than providing good footpaths. A predominance of motor vehicles and higher speeds in a city reduces walkability. Conversely, a culture of restraint in motor vehicle use and speed fosters walkability.

Some European towns and cities are adopting the “naked streets” approach. Traffic control devices, road markings and footpaths are removed in favour of creating shared spaces or slow zones, where motor traffic, cyclists and pedestrians all make use of the entire roadway, albeit at slow speeds.

Walking and cycling are the most sustainable transport modes as they do not require external energy inputs. The Netherlands, Denmark and Germany have increased cycling patronage by providing cycle facilities (both on- and off-road), treatments at intersections, implementing traffic calming or area-wide speed limit reduction, giving right of way to cyclists in many locations and providing cycle parking and integrating cycling with public transport. These measures have been complemented with increased education, promotional ventures and restrictions on car ownership and use. Incentives can also be offered by employers, for example businesses providing showers and cycle lockers in workplaces.

3.6   Freight

It is likely that the demand for freight transport will increase in the future. Increases in e-commerce increase the levels of freight transport on the road network. It is predicted that goods movement between countries will increase in the future which will result in the movement of more containers, both at sea and on land (road and rail). This international trend will have similar effects on New Zealand.

Different methods of accommodating freight on the road network are available. Some researchers suggest that network capacity can be improved by offering financial incentives to freight operators to distribute their goods during off-peak periods. Others suggest that the increases in freight due to increased e-commerce activity can be accommodated by improving freight provisions on the network, for example by using cooperative freight transport systems (where individual vehicles carry goods from several sources), pickup points and consolidated time windows (i.e. freight can only be delivered at certain times).

Similarly, some researchers advocate a system of short term parking spaces for delivery trucks, along with staff at delivery destinations employed specifically to help unload trucks. Collaborative hub networks, where goods are distributed among modes suited to handling different volumes of freight, can improve freight utilisation and therefore system optimisation.

As sustainability becomes more important as a global objective, researchers are also looking at ways of managing transportation to mitigate the environmental effects of freight and thus improve the liveability of surrounding areas. Australian researchers have shown that the best method of reducing emissions from urban freight transport is to increase the vehicle load factors (higher load factors correspond to trucks travelling with a higher proportion of their carrying capacity being used). However, there is a large hidden cost incurred by increasing load factors. Heavier loads break up the road surfaces (which in some cases have not been designed to take those loads) much quicker. Increased road maintenance costs will probably end up being passed on to taxpayers and ratepayers.

Alternatives to using the land transport network for freight transport exist. Sea shipping can help reduce the congestion of the land transportation network by moving goods offshore. Therefore, the efficiency of shipping operations also affects the land transport network. A study of shipping in Eastern Asia found that pendulum-direct coastal shipping services (i.e. goods are shipped directly between origin and destination) are more efficient than services that stop at many ports along the route, as they save transhipment costs and reduce transhipment risks.

The Alameda Corridor Project in California is an example of major intermodal infrastructure that involves a 20-mile (32 km) grade-separated intermodal freight rail corridor. It links the ports of Long Beach and Los Angeles to the transcontinental rail network near downtown Los Angeles. It is a series of bridges, underpasses, overpasses and street improvements that separate freight trains from street traffic and passenger trains, facilitating a more efficient transportation network. This resulted in 200 railway grade crossings in the urban area being eliminated, resulting in decreased congestion and air and noise pollution.

Pricing measures applied to the road network have significant effects on freight transport. Internalising road user costs such as road wear, congestion and traffic crashes by applying distance-based charges can make road freight transport more expensive and therefore rail and shipping become more commercially attractive modes. Alternatively, if pricing measures are focused on private motor vehicles (especially those with single occupants) the congestion relief on the road network can increase freight transport efficiency.

Network capacity and environmental sustainability can be conflicting goals for the freight industry. Research has concluded that, for the Japanese transport network, rail is more efficient than ship transport in terms of carbon emissions. Japan, while being an island nation of similar size to New Zealand, has much denser development and more extensive rail coverage, however.

Appropriate, enforceable regulations regarding freight access to cities by location, time of day and vehicle type, for example, are seen as important [43]. Freight utilisation can be improved by combining different modes and creating collaborative hub networks where goods are transferred between these modes.

3.7   Pricing and charging measures

Appropriate, enforceable regulations regarding freight access to cities by location, time of day and vehicle type, for example, are seen as important [43]. Freight utilisation can be improved by combining different modes and creating collaborative hub networks where goods are transferred between these modes.

An efficient market should have a variety of options available to consumers, competition amongst these options, efficient pricing and economic neutrality (i.e. subsidies and taxes applied consistently between options) [23]. Efficient road pricing schemes are those which accurately reflect the true costs of travel; implementing these can help optimise the system as trips that are seen to be of higher value to society are prioritised over those of lower value.

Road pricing is an economic tool whereby various direct charges are applied for the use of roads. These road charges include fuel taxes, licence fees, parking taxes, tolls and congestion charges, including those which may vary by time of day, by location, or by specific vehicle type. Road pricing has two distinct objectives: revenue generation, usually for road infrastructure financing, and congestion pricing for managing travel demand. Toll roads are an example of revenue generation. Charges for using highoccupancy toll (HOT) lanes or urban tolls for entering a restricted area of a city (such as London) are typical examples of using road pricing for congestion management purposes.

The amount and mix of transport activity that consumers would choose in an efficient market has been studied. Researchers concluded that “in a more optimal market consumers would choose to drive significantly less, use alternative modes more, choose more accessible land use options, and be significantly better off overall as a result.”

Different methods of pricing are currently used in schemes throughout the world and include congestion charging, parking pricing, fuel taxes, distance-based insurance measures and subsidies to public transport measures. Pricing and control measures are generally aimed at either creating revenue or deterring traffic in order to reduce congestion and achieve sustainability.

People’s perceptions of pricing systems are very important factors in determining the system’s success. Some researchers have concluded that a properly devised charging scheme could lead to real differences in future traffic growth and congestion relief, whilst relieving pressure to build new roads and reducing environmental damage. They showed that cities densely concentrated around a single centre tend to achieve larger welfare gains than more dispersed cities with multiple centres, under pricing schemes that involve cordoned areas (generally the central city) which users must pay to enter.

Consistency across modes and locations helps improve the efficiency and public acceptability of pricing schemes. The UK is moving towards a national charging scheme to replace taxes on car ownership and petrol consumption. Some researchers see the need for a consistent pricing scheme that includes rail, air and waterborne transport throughout all the countries in the European Union.

A pricing scheme must be reflective of the actual costs imposed on the transportation system by its users. Some researchers have shown that the optimal tolls for a road network are independent of the actual fixed costs (e.g. construction and maintenance) of the roads. Others suggest that the marginal social cost (the additional cost to the network resulting from one new user) would be a more equitable and efficient method of pricing. Some pricing schemes aim to increase equitability between modes by introducing distance-based costs to private vehicle users. By paying for road use, insurance and environmental effects according to the amount of travel, private vehicle owners are encouraged to drive less. Travel patterns and network performance would be better optimised if externality costs were charged.

Pricing measures can be applied to encourage use of modes previously considered less desirable than private vehicles. For example, a road user charging system can be implemented to provide higher funding and patronage for the rail system. As well as pricing measures that aim to provide users with disbenefits to travel, some measures offer incentives to other kinds of travel (e.g. a change in mode or route choice). Effecting change in user behaviour requires incentives; such incentives may include subsidy systems to influence shift to other modes by making them more financially attractive.

 

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Page created: 10 October 2008