Excerpted from IPCC's Report on Transport & Infrastructure

[HAVE JUST COPY-PASTED THIS STUFF FOR REFINEMENT AS A BLOG.]

5.3.1.5 Road transport: mode shifts Personal motor vehicles consume much more energy and
emit far more GHGs per passenger-km than other surface passenger modes. And the number of cars (and light trucks) continues to increase virtually everywhere in the world. Growth
in GHG emissions can be reduced by restraining the growth in personal vehicle ownership. Such a strategy can, however, only be successful if high levels of mobility and accessibility can be
provided by alternative means.

In general, collective modes of transport use less energy and generate less GHGs than private cars. Walking and biking emit even less. There is important worldwide mitigation potential if
public and non-motorised transport trip share loss is reversed.
The challenge is to improve public transport systems in order to preserve or augment the market share of low-emitting modes. If public transport gets more passengers, it is possible to increase the frequency of departures, which in turn may attract new passengers (Akerman and Hojer, 2006).
The USA is somewhat of an anomaly, though. In the USA, passenger travel by cars generates about the same GHG emissions as bus and air travel on a passenger-km basis (ORNL transportation Energy Databook; ORNL, 2006). That is mostly because buses have low load factors in the USA. Thus, in the USA, a bus-based strategy or policy will not necessarily
lower GHG emissions. Shifting passengers to bus is not simply a matter of filling empty seats. To attract more passengers, it is necessary to enhance transit service. That means more
buses operating more frequently – which means more GHG emissions. It is even worse than that, because transit service is already offered where ridership26 demand is greatest. Adding
more service means targeting less dense corridors or adding more service on an existing route. There are good reasons to promote transit use in the USA, but energy use and GHGs are
not among them.
Virtually everywhere else in the world, though, transit is used more intensively and therefore has a GHG advantage relative to cars. Table 5.4 shows the broad average GHG emissions
from different vehicles and transport modes in a developing country context. GHG emissions per passenger-km are lowest for transit vehicles and two-wheelers. It also highlights the fact
that combining alternative fuels with public transport modes can reduce emissions even further.


It is diffi cult to generalize, though, because of substantial
differences across nations and regions. The types of buses,
occupancy factors, and even topography and weather can
affect emissions. For example, buses in India and China tend

to be more fuel-effi cient than those in the industrialized world,
primarily because they have considerably smaller engines and
lack air conditioning (Sperling and Salon, 2002).
Public transport
In addition to reducing transport emissions, public transport
is considered favourably from a socially sustainable point of
view because it gives higher mobility to people who do not
have access to car. It is also attractive from an economically
sustainable perspective since public transport provides more
capacity at less marginal cost. It is less expensive to provide
additional capacity by expanding bus service than building new
roads or bridges. The expansion of public transport in the form
of large capacity buses, light rail transit and metro or suburban
rail can be feasible mitigation options for the transport sector.
The development of new rail services can be an effective
measure for diverting car users to carbon-effi cient mode
while providing existing public transport users with upgraded
service. However, a major hurdle is higher capital and possibly
operating cost of the project. Rail is attractive and effective
at generating high ridership in very dense cities. During the
1990s, less capital-intensive public transport projects such as
light rail transit (LRT) were planned and constructed in Europe,
North America and Japan. The LRT systems were successful in
some regions, including a number of French cities where land
use and transport planning is often well integrated (Hylen and
Pharoah, 2002), but less so in other cities especially in the USA
(Richmond, 2001; Mackett and Edwards, 1998), where more
attention has been paid to this recently.
Around the world, the concept of bus rapid transit (BRT)
is gaining much attention as a substitute for LRT and as an
enhancement of conventional bus service. BRT is not new.
Plans and studies for various BRT type alternatives have been
prepared since the 1930s and a major BRT system was installed
in Curitiba, Brazil in the 1970s (Levinson et al., 2002). But
only since about 2000 has the successful Brazilian experience
gained serious attention from cities elsewhere.
BRT is ‘a mass transit system using exclusive right of way
lanes that mimic the rapidity and performance of metro systems,
but utilizes bus technology rather than rail vehicle technology’
(Wright, 2004). BRT systems can be seen as enhanced bus service
and an intermediate mode between conventional bus service
and heavy rail systems. BRT includes features such as exclusive
right of way lanes, rapid boarding and alighting, free transfers
between routes and preboard fare collection and fare verifi cation,
as well as enclosed stations that are safe and comfortable, clear
route maps, signage and real-time information displays, modal
integration at stations and terminals, clean vehicle technologies
and excellence in marketing and customer service. To be most
effective, BRT systems (like other transport initiatives) should
be part of a comprehensive strategy that includes increasing
vehicle and fuel taxes, strict land-use controls, limits and higher
fees on parking, and integrating transit systems into a broader
package of mobility for all types of travellers (IEA, 2002b).
Most BRT systems today are being delivered in the range of
1–15 million US$/km, depending upon the capacity requirements
and complexity of the project. By contrast, elevated rail systems
and underground metro systems can cost from 50 million US$

to over 200 million US$/km (Wright, 2004). BRT systems now
operate in several cities throughout North America, Europe,
Latin America, Australia, New Zealand and Asia. The largest
and most successful systems to date are in Latin America in
Bogotá, Curitiba and Mexico City (Karekezi et al., 2003).
Analysing the Bogotá Clean Development Mechanism
project gives an insight into the cost and potential of
implementing BRT in large cities. The CDM project shows the
potential of moving about 20% of the city population per day
on the BRT that mainly constitutes putting up dedicated bus
lanes (130 km), articulated buses (1200) and 500 other large
buses operating on feeder routes. The project is supported by an
integrated fare system, centralized coordinated fl eet control and
improved bus management27. Using the investment costs, an
assumed operation and maintenance of 20–50%28 of investment
costs per year, fuel costs of 40 to 60 US$ per barrel in 2030 and
a discount rate of 4%, a BRT lifespan of 30 years, the cost of
implementing BRT in the city of Bogotá was estimated to range
from 7.6 US$/tCO2 to 15.84 US$/tCO2 depending on the price
of fuel and operation and maintenance (Table 5.5). Comparing
with results of Winkelman (2006), BRT cost estimates ranged
from 14-66 US$/tCO2 depending on the BRT package involved
(Table 5.6). The potential for CO2 reduction for the city of
Bogotá was determined to average 247,000 tCO2 per annum or
7.4 million tCO2 over a 30 year lifespan of the project.
Non-motorized transport (NMT)
The prospect for the reduction in CO2 emissions by
switching from cars to non-motorized transport (NMT) such as
walking and cycling is dependent on local conditions. In the
Netherlands, where 47% of trips are made by NMT, the NMT
plays a substantial role up to distances of 7.5 km and walking
up to 2.5 km (Rietveld, 2001). As more than 30% of trips made
in cars in Europe cover distances of less than 3 km and 50% are
less than 5 km (EC, 1999), NMT can possibly reduce car use
in terms of trips and, to a lesser extent, in terms of kilometres.
While the trend has been away from NMT, there is considerable
potential to revive interest in NMT. In the Netherlands, with
strong policies and cultural commitment, the modal share of
bicycle and walking for accessing trains from home is about 35
to 40% and 25% respectively (Rietveld, 2001).
Walking and cycling are highly sensitive to the local built
environment (ECMT, 2004a; Lee and Mouden, 2006). In
Denmark, where the modal share of cycling is 18%, urban
planners seek to enhance walking and cycling by shortening
journey distances and providing better cycling infrastructure
(Dill and Carr 2003, Page, 2005). In the UK where over 60%
of people live within a 15 minute bicycle ride of a station,
NMT could be increased by offering convenient, secure bicycle
parking at stations and improved bicycle carriage on trains
(ECMT, 2004a).
Safety is an important concern. NMT users have a much
higher risk per trip of being involved in an accident than those
using cars, especially in developing countries where most
NMT users cannot afford to own a car (Mohan and Tiwari,
1999). Safety can be improved through traffi c engineering and
campaigns to educate drivers. An important co-benefi t of NMT,

gaining increasing attention in many countries, is public health
(National Academies studies in the USA; Pucher, 2004).
In Bogotá, in 1998, 70% of the private car trips were under
3 km. This percentage is lower today thanks to the bike and
pedestrian facilities. The design of streets was so hostile to
bicycle travel that by 1998 bicycle trips accounted for less than
1% of total trips. After some 250 km of new bicycle facilities were
constructed by 2001 ridership had increased to 4% of total trips.
In most of Africa and in much of southern Asia, bicyclists and
other non-motorised and animal traction vehicles are generally
tolerated on the roadways by authorities. Non-motorised goods
transport is often important for intermodal goods transport. A
special form of rickshaw is used in Bangladesh, the bicycle
van, which has basically the same design as a rickshaw (Hook,
2003).
Mitigation potential of modal shifts for passenger
transport
Rapid motorization in the developing world is beginning to
have a large effect on global GHG emissions. But motorization
can evolve in quite different ways at very different rates. The
amount of GHG emissions can be considerably reduced by
offering strong public transport, integrating transit with effi cient
land use, enhancing walking and cycling, encouraging minicars
and electric two-wheelers and providing incentives for effi cient
vehicles and low-GHG fuels. Few studies have analyzed the
potential effect of multiple strategies in developing nations,
partly because of a severe lack of reliable data and the very
large differences in vehicle mix and travel patterns among
varying areas.
Wright and Fulton (2005) estimated that a 5% increase in
BRT mode share against a 1% mode share decrease of private
automobiles, taxis and walking, plus a 2% share decrease of
mini-buses can reduce CO2 emissions by 4% at an estimated
cost of 66 US$/tCO2 in typical Latin American cities. A 5%
or 4% increase in walking or cycling mode share in the same
scenario analysis can also reduce CO2 emissions by 7% or
4% at an estimated cost of 17 or 15 US$/tCO2, respectively
(Table5.6). Although the assumptions of a single infrastructure
unit cost and its constant impact on modal share in the analysis
might be too simple, even shifting relatively small percentages
of mode share to public transport or NMT can be worthwhile,
because of a 1% reduction in mode share of private automobiles
represents over 1 MtCO2 through the 20-year project period.
Figure 5.13 shows the GHG transport emission results,
normalized to year 2000 emissions, of four scenario analyses
of developing nations and cities (Sperling and Salon, 2002).
For three of the four cases, the ‘high’ scenarios are ‘businessas-
usual’ scenarios assuming extrapolation of observable
and emerging trends with an essentially passive government
presence in transport policy. The exception is Shanghai, which
is growing and changing so rapidly that ‘business-as-usual’ has
little meaning. In this case the high scenario assumes both rapid

motorization and rapid population increases, with the execution
of planned investments in highway infrastructure while at the
same time efforts to shift to public transport falter (Zhou and
Sperling, 2001).
5.3.1.6 Improving driving practices (eco-driving)
Fuel consumption of vehicles can be reduced through
changes in driving practices. Fuel-effi cient driving practices,
with conventional combustion vehicles, include smoother
deceleration and acceleration, keeping engine revolutions low,
shutting off the engine when idling, reducing maximum speeds
and maintaining proper tyre pressure (IEA, 2001). Results from
studies conducted in Europe and the USA suggested possible
improvement of 5–20% in fuel economy from eco-driving
training. The mitigation costs of CO2 by eco-driving training
were mostly estimated to be negative (ECMT/IEA, 2005).
Eco-driving training can be attained with formal training
programmes or on-board technology aids. It applies to drivers
of all types of vehicles, from minicars to heavy-duty trucks.
The major challenge is how to motivate drivers to participate in
the programme, and how to make drivers maintain an effi cient
driving style long after participating (IEA, 2001). In the
Netherlands, eco-driving training is provided as part of driving
school curricula (ECMT/IEA, 2005).
5.3.2 Rail
Railway transport is widely used in many countries. In
Europe and Japan, electricity is a major energy source for rail,
while diesel is a major source in North America. Coal is also still
used in some developing countries. Rail’s main roles are high
speed passenger transport between large (remote) cities, high
density commuter transport in the city and freight transport over
long distances. Railway transport competes with other transport
modes, such as air, ship, trucks and private vehicles. Major



5.4: MITIGATION POTENTIAL

As discussed earlier, under ‘business-as-usual’ conditions
with assumed adequate supplies of petroleum, GHG emissions
from transport are expected to grow steadily during the next few
decades, yielding about an 80% increase from 2002–2030 or
2.1% per year. This growth will not be evenly distributed; IEA
projections of annual CO2 growth rates for 2002–2030 range
from 1.3% for the OECD nations to 3.6% for the developing
countries. The potential for reducing this growth will vary
widely across countries and regions, as will the appropriate
policies and measures that can accomplish such reduction.
Analyses of the potential for reducing GHG emissions in the
transport sector are largely limited to national or sub-national
studies or to examinations of technologies at the vehicle level,
for example well-to-wheel analyses of alternative fuels and drive
trains for light-duty vehicles. The TAR presented the results of
several studies for the years 2010 and 2020 (Table 3.16 of the
TAR), with virtually all limited to single countries or to the
EU or OECD. Many of these studies indicated that substantial
reductions in transport GHG emissions could be achieved at
negative or minimal costs, although these results generally used
optimistic assumptions about future technology costs and/or
did not consider trade-offs between vehicle effi ciency and other
(valued) vehicle characteristics. Studies undertaken since the
TAR have tended to reach conclusions generally in agreement
with these earlier studies, though recent studies have focused
more on transitions to hydrogen used in fuel cell vehicles.
This section will discuss some available studies and
provide estimates of GHG emissions reduction potential and
costs/tonne of carbon emissions reduced for a limited set of
mitigation measures. These estimates do not properly refl ect
the wide range of measures available, many of which would
likely be undertaken primarily to achieve goals other than GHG
reduction (or saving energy), for example to provide mobility
to the poor, reduce air pollution and traffi c reduce congestion.
The estimates do not include:
• Measures to reduce shipping emissions;
• Changes in urban structure that would reduce travel demand
and enhance the use of mass transit, walking and bicycling;
• Transport demand management measures, including parking
‘cash out’, road pricing, inner city entry charges, etc.
5.4.1 Available worldwide studies
Two recent studies – the International Energy Agency’s
World Energy Outlook (IEA, 2004a) and the World Business
Council on Sustainable Development’s Mobility 2030 (WBCSD,
2004a) – examined worldwide mitigation potential but were
limited in scope. The IEA study focused on a few relatively
modest measures and the WBCSD examined the impact of
specifi ed technology penetrations on the road vehicle sector
(the study sponsors are primarily oil companies and automobile
manufacturers) without regard to either cost or the policies
needed to achieve such results. In addition, IEA has developed
a simple worldwide scenario for light-duty vehicles that also
explores radical reductions in GHG emissions.

World Energy Outlook postulates an ‘Alternative scenario’ to
their Reference scenario projection described earlier, in which
vehicle fuel effi ciency is improved, there are increased sales of
alternative-fuel vehicles and the fuels themselves and demand
side measures reduce transport demand and encourage a switch
to alternative and less energy intensive transport modes.




In deciding to institute a new fuel economy standard,
governments should consider the following:
• Basing stringency decisions on existing standards elsewhere
requires careful consideration of differences between the
home market and compared markets in fuel quality and
availability; fuel economy testing methods; types and
sizes of vehicles sold; road conditions that may affect
the robustness of key technologies; and conditions that
may affect the availability of technologies, for example,
availability of sophisticated repair facilities.
• There are a number of different approaches to selecting
stringency levels for new standards. Japan selected its
weight class standards by examining ‘top runners’ –
exemplary vehicles in each weight class that could serve as
viable targets for future fl eet wide improvements. Another
approach is to examine the costs and fuel saving effects
of packages of available technologies on several typical
vehicles, applying the results to the new vehicle fl eet (NRC,
2002). Other analyses have derived cost curves (percent
increase in fuel economy compared with technology cost)
for available technology and applied these to corporate or
national fl eets (Plotkin et al., 2002). These approaches are
not technology-forcing, since they focus on technologies
that have already entered the fl eet in mass-market form.
More ambitious standards could demand the introduction
of emerging technologies. Selection of the appropriate level
of stringency depends, of course, on national goals and
concerns. Further, the selection of enforcement deadlines
should account for limitations on the speed with which
vehicle manufacturers can redesign multiple models and
introduce the new models on a schedule that avoids severe
economic disruption.
• The structure of the standard is as important as its level of
stringency. Basing target fuel economy on vehicle weight
(Japan, China) or engine size (Taiwan, South Korea) will
tend to even out the degree of diffi culty the standards impose
on competing automakers, but will reduce the potential fuel
economy gains that can be expected (because weight-based
standards eliminate weight reduction and engine-size-based
standards eliminate engine downsizing as viable means of
achieving the standards). Basing the standard on vehicle
wheelbase times track width may provide safety benefi ts by
providing a positive incentive to maintain or increase these
attributes. Using a uniform standard for all vehicles or for
large classes of vehicles (as in the US) is simple and easy to
explain, but creates quite different challenges on different
manufacturers depending on the market segments they
focus on.
• Allowing trading of fuel economy ‘credits’ among different
vehicles or vehicle categories in an automaker’s fl eet, or
even among competing automakers, will reduce the overall
cost of standards without reducing the total societal benefi ts,
but may incur political costs from accusations of allowing
companies or individuals to ‘buy their way out’ of effi ciency
requirements.
• Alternatives (or additions) to standards are worth
investigating. For example, ‘feebates’, which award cash
rebates to new vehicles whose fuel economy is above a
designated level (often the fl eet average) and charge a fee
to vehicles with lower fuel economy, may be an effective
market-based measure to increase fl eet fuel economy. An
important advantage of feebates is that they provide a
‘continuous’ incentive to improve fuel economy, because
an automaker can always gain a market advantage by
introducing vehicles that are more effi cient than the current
average.
5.5.1.5 Transport Demand Management
Transport Demand Management (TDM) is a formal
designation for programmes in many countries that improve
performance of roads by reducing traffi c volumes (Litman,
2003). There are many potential TDM strategies in these
programmes with a variety of impacts. Some improve transport
diversity (the travel options available to users). Others provide
incentives for users to reduce driving, changing the frequency,
mode, destination, route or timing of their travel. Some reduce
the need for physical travel through mobility substitutes or
more effi cient land use. Some involve policy reforms to correct
current distortions in transport planning practices. TDM is
particularly appropriate in developing country cities, because
of its low costs, multiple benefi ts and potential to redirect the
motorization process. In many cases, effective TDM during
early stages of development can avoid problems that would
result if communities become too automobile dependent. This
can help support a developing country’s economic, social and
environmental objectives (Gwilliam et al., 2004).



The set of strategies to be implemented will vary depending
on each country’s demographic, geographic and political
conditions. TDM strategies can have cumulative and synergetic
impacts, so it is important to evaluate a set of TDM programmes
as a package, rather than as an individual programme. Effective
strategies usually include a combination of positive incentives
to use alternative modes (‘carrots’ or ‘sweeteners’) and negative
incentives to discourage driving (‘sticks’ or ‘levellers’).


Some major strategies such as
pricing and land-use planning are addressed above. Below is a
selective review of additional TDM strategies with signifi cant
potential to reduce vehicle travel and GHGs.
Employer travel reduction strategies gained prominence
from a late 1980s regulation in southern California that required
employers with 100 or more employees to adopt incentives and
rules to reduce the number of car trips by employees commuting
to work (Giuliano et al., 1993). The State of Washington in the
USA kept a state law requiring travel plans in its most urban
areas for employers with 100 or more staff. The law reduced
the percentage of employees in the targeted organizations who
drove to work from 72–68% and affected about 12% of all trips
made in the area. In the Netherlands, the reduction in single
occupant commute trips from a travel plan averaged 5–15%.
In the UK, in very broad terms, the average effectiveness of
UK travel plans might be 6% in trips by drive alone to work
and 0.74% in the total vehicle-km travelled to work by car. The
overall effectiveness was critically dependent on both individual
effectiveness and levels of plan take-up (Rye, 2002).
Parking supply for employees is so expensive that employers
naturally have an incentive to reduce parking demand. The
literature found the price elasticity of parking demand for
commuting at –0.31 to –0.58 (Deuker et al., 1998) and –0.3
(Veca and Kuzmyak, 2005) based on a non-zero initial parking
price. The State of California enacted legislation that required
employers with 50 or more persons who provided parking
subsidies to offer employees the option to choose cash in
lieu of a leased parking space, in a so-called parking cash-out
programme. In eight case studies of employers who complied
with the cash-out programme, the solo driver share fell from
76% before cashing out to 63% after cashing out, leading to
the reduction in vehicle-km for commuting by 12%. If all the
commuters who park free in easily cashed-out parking spaces
were offered the cash option in the USA, it would reduce
vehicle-km travelled per year by 6.3 billion (Shoup, 1997).
Reducing car travel or CO2 emissions by substituting
telecommuting for actual commuting has often been cited in
the literature, but the empirical results are limited. In the USA,
a micro-scale study estimated that 1.5% of the total workforce
telecommuted on any day, eliminating at most 1% of total
household vehicle-km travelled (Mokhtarian, 1998), while
a macro-scale study suggested that telecommuting reduced
annual vehicle-km by 0–2% (Choo et al., 2005).
Reduction of CO2 emissions by hard measures, such as car
restraint, often faces public opposition even when the proposed
measures prove effective. Soft measures, such as a provision of
information and use of communication strategies and educational
techniques (OECD, 2004a) can be used for supporting the
promotion of hard measures. Soft measures can also be directly

helpful in encouraging a change in personal behaviour leading
to an effi cient driving style and reduction in the use of the car
(Jones, 2004). Well organized soft measures were found to be
effective for reducing car travel while maintaining a low cost.
Following travel awareness campaigns in the UK, the concept
of Individualized marketing, a programme based on a targeted,
personalized, customized marketing approach, was developed
and applied in several cities for reducing the use of the car. The
programme reduced car trips by 14% in an Australian city, 12%
in a German city and 13% in a Swedish city. The Travel Blending
technique was a similar programme based on four special kits
for giving travel-feedback to the participants. This programme
reduced vehicle-km travelled by 11% in an Australian city.
The monitoring study after the programme implementation in
Australian cities also showed that the reduction in car travel
was maintained (Brog et al., 2004; Taylor and Ampt, 2003).
Japanese cases of travel-feedback programmes supported the
effectiveness of soft measures for reducing car travel. The
summary of the travel-feedback programmes in residential
areas, workplaces and schools indicated that car use was reduced
by 12% and CO2 emissions by 19%. It also implied that the
travel-feedback programmes with a behavioural plan requiring
a participant to make a plan for a change showed better results
than programmes without one (Fujii and Taniguchi, 2005).