topic 2 – urban transportation and energy
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Topic 2 – Urban Transportation and Energy. A – Transportation and Energy Consumption B – Energy, Transportation and Urban Form C – Alternative Sources of Energy for Urban Transportation. Transportation and Energy Consumption. A. 1. Energy in a Mobile World 2. Utility Factors - PowerPoint PPT PresentationTRANSCRIPT
Transport and the Urban Environment
Topic 2 – Urban Transportation and Energy
A – Transportation and Energy A – Transportation and Energy ConsumptionConsumption
B – Energy, Transportation and Urban B – Energy, Transportation and Urban FormForm
C – Alternative Sources of Energy for C – Alternative Sources of Energy for Urban TransportationUrban Transportation
Transportation and Energy Consumption
1. Energy in a Mobile World1. Energy in a Mobile World 2. Utility Factors2. Utility Factors 3. Petroleum Dependency3. Petroleum Dependency 4. Combustion of Hydrocarbons4. Combustion of Hydrocarbons 5. Energy Consumption5. Energy Consumption
AA
Energy in a Mobile World
NatureNature Energy is movement or the possibility of creating movement.Energy is movement or the possibility of creating movement. Exists as potential (stored) and kinetic (used) forms.Exists as potential (stored) and kinetic (used) forms. Conversion of potential to kinetic.Conversion of potential to kinetic. Movement can be ordered (mechanical energy) or disordered Movement can be ordered (mechanical energy) or disordered
(thermal energy).(thermal energy). Major tendency is to move from order to disorder.Major tendency is to move from order to disorder.
ImportanceImportance Human activities are closely dependant to the usage of several forms Human activities are closely dependant to the usage of several forms
and sources of energy.and sources of energy. Development processes have increased demand and reliance on Development processes have increased demand and reliance on
energy. energy. Human activities are strongly supported by the usage of energy.Human activities are strongly supported by the usage of energy. Overcoming territories in a global economy requires a substantial Overcoming territories in a global economy requires a substantial
amount of work.amount of work. Work related to transfers of goods, people and information has Work related to transfers of goods, people and information has
increased significantly.increased significantly. Growing share of transportation in the total energy spent.Growing share of transportation in the total energy spent.
A-1A-1
Sources of EnergyA-1A-1
Chemical• Fossil fuels (Combustion)Nuclear• Uranium (Fission of atoms)
Energy
Non-Renewable
Renewable Chemical• Muscular (Oxidization)Nuclear• Geothermal (Conversion)• Fusion (Fusion of hydrogen)Gravity• Tidal, hydraulic (Kinetic)Indirect Solar• Biomass (Photosynthesis)• Wind (Pressure differences)Direct Solar• Photovoltaic cell (Conversion)
Energy Content of some Fossil Fuels (in MJ/kg)
0 20 40 60 80 100 120 140
Hydrogen
Gasoline
Natural Gas
Methane
Methanol
Ethanol
Kerosene
Crude Oil
Coal
Wood
A-1A-1
World Fossil Fuel Consumption, 1950-1998 (in million of tons of equivalent oil)
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
A-1A-1
Energy in a Mobile World
Energy exists in various formsEnergy exists in various forms Mechanical, thermal, chemical, electrical, radiant, and atomic Mechanical, thermal, chemical, electrical, radiant, and atomic
and are all interconvertible.and are all interconvertible. Forms of energy come from sources qualified as renewable Forms of energy come from sources qualified as renewable
and non-renewable.and non-renewable. RenewabilityRenewability
Based upon the scale of human events and if the source can Based upon the scale of human events and if the source can be replaced during that period.be replaced during that period.
Wood is a renewable biomass energy source as long as Wood is a renewable biomass energy source as long as adequate conditions are kept for reserves to be replenished.adequate conditions are kept for reserves to be replenished.
Rates of exploitation / deforestation in a number of areas are Rates of exploitation / deforestation in a number of areas are so high that biomass may be considered as a non-renewable so high that biomass may be considered as a non-renewable source in those circumstances.source in those circumstances.
A-1A-1
A-1A-1 Energy in a Mobile World
Choice of an energy sourceChoice of an energy source Depend on a number of utility factors.Depend on a number of utility factors. Factors that favors a specific source.Factors that favors a specific source. Currently favoring the usage of fossil fuels, notably petroleum.Currently favoring the usage of fossil fuels, notably petroleum.
Energy and workEnergy and work Many efforts have been done to alleviate work.Many efforts have been done to alleviate work. Creating more work performed by extra-human agents like Creating more work performed by extra-human agents like
motors and the usage of even more energy.motors and the usage of even more energy. Modification of the environmentModification of the environment
Rendering space suitable for human activities.Rendering space suitable for human activities. Clearing land for agriculture.Clearing land for agriculture. Modifying the hydrography (irrigation).Modifying the hydrography (irrigation). Establishing distribution infrastructure.Establishing distribution infrastructure. Constructing and conditioning (temperature and light) Constructing and conditioning (temperature and light)
enclosed structures. enclosed structures.
Energy in a Mobile World
Appropriation and processing resourcesAppropriation and processing resources Extraction of agricultural products from the biomass and raw Extraction of agricultural products from the biomass and raw
materials (minerals, oil, lumber, etc.) for human needs.materials (minerals, oil, lumber, etc.) for human needs. Disposal of wastes, which are in an advanced industrial Disposal of wastes, which are in an advanced industrial
society very work intensive to safely dispose. society very work intensive to safely dispose. Modifies products from the biomass, raw materials and goods Modifies products from the biomass, raw materials and goods
to manufacture according to economic needs.to manufacture according to economic needs. Over the last 200 years, work related to processing was Over the last 200 years, work related to processing was
considerably mechanized (e.g. robotized assembly lines).considerably mechanized (e.g. robotized assembly lines).
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Energy in a Mobile World
TransferTransfer Movements of freight, people and information from one place Movements of freight, people and information from one place
to another.to another. Attenuate the spatial inequities in the location of resources by Attenuate the spatial inequities in the location of resources by
overcoming distance.overcoming distance. The less energy costs per ton or passenger - kilometer, the The less energy costs per ton or passenger - kilometer, the
less importance has transfers.less importance has transfers. Overcoming territories in a global economy requires a Overcoming territories in a global economy requires a
substantial amount of work.substantial amount of work. Work related to transfers of goods, people and information has Work related to transfers of goods, people and information has
increased significantly.increased significantly. Growing share of transportation in the total energy spent.Growing share of transportation in the total energy spent. The United States is an economy using massive amounts of The United States is an economy using massive amounts of
energy in the transport sector.energy in the transport sector.
A-1A-1
Energy in a Mobile World
United StatesUnited States Huge consumer of energy.Huge consumer of energy. Pattern of consumption is strongly linked to the attributes of Pattern of consumption is strongly linked to the attributes of
the American economy and territory.the American economy and territory. Accounts for 5% of the global population, but for 25% of the Accounts for 5% of the global population, but for 25% of the
produced energy.produced energy. Transportation accounts for about 24% of all the energy used Transportation accounts for about 24% of all the energy used
in the United States.in the United States.
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Demand for Refined Petroleum Products by Sector in the United States, 1970-1998 (in Quadrillion BTUs)
0
5
10
15
20
25
1970 1975 1980 1985 1990 1991 1992 1993 1994 1995 1996 1997 1998
Transportation
Residential & CommercialIndustrial
Electric Utilities
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Evolution of Energy SourcesA-1A-1
0% 20% 40% 60% 80% 100%
15th Century
Mid 19th Century
Early 20thCentury
Late 20th Century
Mid 21st Century
Animal
Biomass
Coal
Oil
Natural Gas
Nuclear
Hydrogen
Energy in a Mobile World
1515thth Century Century Traditional societies.Traditional societies. Rely only on muscular and biomass sources to answer their Rely only on muscular and biomass sources to answer their
energy needs.energy needs. Mainly the characteristics of the Middle Ages and other Mainly the characteristics of the Middle Ages and other
previous historical periods.previous historical periods. Mid 19Mid 19thth Century Century
Beginning of the Industrial revolution.Beginning of the Industrial revolution. Considerably modified energy sources.Considerably modified energy sources. Greater reliance on coal.Greater reliance on coal.
Early 20Early 20thth Century Century Middle of the industrial revolution.Middle of the industrial revolution. Coal is dominant source of energy.Coal is dominant source of energy. Gradual shift towards higher energy content sources like oil. Gradual shift towards higher energy content sources like oil.
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Energy in a Mobile World
End of 20End of 20thth Century Century Modern energy intensive society.Modern energy intensive society. Contemporary technological developments allowed:Contemporary technological developments allowed:
Higher occurrence, a better transferability, reliability, Higher occurrence, a better transferability, reliability, storability, flexibility, safety and cleanliness of high energy storability, flexibility, safety and cleanliness of high energy content sources for a low price.content sources for a low price.
Emphasis on petroleum products as the main provider of Emphasis on petroleum products as the main provider of energy.energy.
Reached the point where the world economy highly depends Reached the point where the world economy highly depends on the internal combustion engine and supporting industries.on the internal combustion engine and supporting industries.
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Global Energy Systems Transition, (% of market)A-1A-1
20001850 21502050 210019501900
100
80
60
40
20
0
Solids
Liquids
Gases
Wood
Coal
Oil
Natural Gas
Hydrogen
Utility Factors
NatureNature Favor the usage of petroleum as the main source of energy for Favor the usage of petroleum as the main source of energy for
transport activities.transport activities. The utility factors were so convenient that a dependency on The utility factors were so convenient that a dependency on
petroleum was created.petroleum was created. OccurrenceOccurrence
Location of energy sources considering the demand.Location of energy sources considering the demand. Several energy sources are only available when a Several energy sources are only available when a
transportation system existstransportation system exists Can support transfers between the supply and the demand.Can support transfers between the supply and the demand. Exploitation of oil fields in several regions of the World (Middle Exploitation of oil fields in several regions of the World (Middle
East, Siberia, etc.).East, Siberia, etc.). Only possible when an efficient transportation system based Only possible when an efficient transportation system based
upon pipelines and tankers was established.upon pipelines and tankers was established.
A-2A-2
Utility Factors
TransferabilityTransferability Distance over which an energy source can be transported.Distance over which an energy source can be transported. Depends on its physical form (solid, liquid or gas), its energy Depends on its physical form (solid, liquid or gas), its energy
content, and on the available transport technology.content, and on the available transport technology. Most petroleum products are in a liquid, more or less viscous, Most petroleum products are in a liquid, more or less viscous,
form.form. Offer an efficient form to be transferred.Offer an efficient form to be transferred. Economies of scale in transportation enhance transferability. Economies of scale in transportation enhance transferability.
A-2A-2
1975Modern VLCC (305 m)1942T2 Tanker (153 m)
Economies of Scale in Oil TransportationA-2A-2
Utility Factors
Energy contentEnergy content Available energy per weight or volume unit of a source.Available energy per weight or volume unit of a source. A low energy content is inadequate when demand is high and A low energy content is inadequate when demand is high and
concentrated in space.concentrated in space. Gasoline and other petroleum products have a high energy Gasoline and other petroleum products have a high energy
content compared to other fossil fuels like coal.content compared to other fossil fuels like coal. Even more when compared to gravity and solar energy. Even more when compared to gravity and solar energy.
ReliabilityReliability Continuous availability is an advantage over intermittent Continuous availability is an advantage over intermittent
sources.sources. Many sources and continuous supply through maritime and Many sources and continuous supply through maritime and
land routes have given a relative reliability for petroleum land routes have given a relative reliability for petroleum products.products.
A-2A-2
Utility Factors
Some contemporary military interventions were performed to Some contemporary military interventions were performed to insure the reliability of oil sources and their transport. insure the reliability of oil sources and their transport.
StorabilityStorability An energy source has an advantage when it can be stored to An energy source has an advantage when it can be stored to
answer variations in demands and interruptions of supplies. answer variations in demands and interruptions of supplies. In liquid form, petroleum products are easily stored.In liquid form, petroleum products are easily stored.
FlexibilityFlexibility Capacity of an energy source to answer multiple usage.Capacity of an energy source to answer multiple usage. Petroleum by-products are the basis of whole industrial Petroleum by-products are the basis of whole industrial
sectors (petrochemical).sectors (petrochemical). Synthesize goods like plastics, pharmaceutical products, and Synthesize goods like plastics, pharmaceutical products, and
synthetic rubber.synthetic rubber.
A-2A-2
Utility Factors
SafetySafety Sources that can be provided and used at low risks (human Sources that can be provided and used at low risks (human
and environmental) are an advantage.and environmental) are an advantage. The petrochemical industry presents some risks (accidents The petrochemical industry presents some risks (accidents
during extraction, refining, transport and usage).during extraction, refining, transport and usage). Oil is considered a safe source of energy for its production and Oil is considered a safe source of energy for its production and
usage.usage. CleanlinessCleanliness
Sources that produce few waste and are cleanly used have an Sources that produce few waste and are cleanly used have an advantage.advantage.
In regards of other conventional energy sources like coal and In regards of other conventional energy sources like coal and wood and of the available technology, oil is cleaner to use and wood and of the available technology, oil is cleaner to use and produces a limited amount of waste. produces a limited amount of waste.
A-2A-2
Utility Factors
PricePrice Sources at low cost are generally more used.Sources at low cost are generally more used. A function of the occurrence, the transferability and the energy A function of the occurrence, the transferability and the energy
content of the source.content of the source. Massive investments on large scale extraction, refining and Massive investments on large scale extraction, refining and
transport of petroleum products.transport of petroleum products. Constant supply.Constant supply. Intensive competition from several oil producing countries Intensive competition from several oil producing countries
(although with some monopolistic control - OPEC).(although with some monopolistic control - OPEC). Oil price is cheaper than many other sources.Oil price is cheaper than many other sources.
A-2A-2
A-3A-3 Petroleum Dependency
The reliance on petroleumThe reliance on petroleum Petroleum products account for more than 97% of the energy Petroleum products account for more than 97% of the energy
consumption by transportation modes.consumption by transportation modes. Transportation accounts for a growing share of the oil used.Transportation accounts for a growing share of the oil used. The share of transportation has increased in the and now The share of transportation has increased in the and now
accounts for more the 55% of the oil used.accounts for more the 55% of the oil used. Since 1973 the price of petroleum has increased significantly.Since 1973 the price of petroleum has increased significantly. The transport sector consumed 42% of the oil in OECD The transport sector consumed 42% of the oil in OECD
countries in 1973.countries in 1973. This share climbed to 55.1% in 1995.This share climbed to 55.1% in 1995. The sprawl of economic activities, notably in urban areas, is The sprawl of economic activities, notably in urban areas, is
strongly linked to this trend.strongly linked to this trend.
Oil Energy Consumption by Sector for OECD countries, 1973-1995
42
55.1
26.3
20
6.3
6.3
25.3
18.6
0% 20% 40% 60% 80% 100%
1973
1995
TransportationIndustryNon-Energy UseOther Sectors
A-3A-3
Petroleum Dependency
Impacts of increasing pricesImpacts of increasing prices Increasing the fuel efficiency of vehicles.Increasing the fuel efficiency of vehicles. Use of alternative sources of energy.Use of alternative sources of energy.
A-3A-3
World Oil Production and Demand, 1996 (in m tons)
-600
-400
-200
0
200
400
600
800
1000
North America Latin America Middle East Asia/Oceania Africa WesternEurope
Eastern Europe
Production Demand Balance
A-3A-3
World Oil Production and Estimated Resources, 1900-2100 (in billions of barrels)
0
5
10
15
20
25
30
Actual
Predicted
A-3A-3
Cost of Gasoline, United States, 1999
37%
36%
13%
14% Crude Oil
Federal and State Taxes
Refining costs andprofits
Distribution, retail &marketing costs andprofits
A-3A-3
Gasoline Prices, 1978-1999 Selected Countries (current 1998 dollars per gallon)
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
1978 1982 1986 1990 1994 1996 1997 1998 1999
JapanFranceUnited KingdomGermanyCanadaUnited Statesd
A-3A-3
Combustion of Hydrocarbons
Internal combustion engineInternal combustion engine Almost all transportation modes depend on the internal Almost all transportation modes depend on the internal
combustion engine.combustion engine. For the majority of internal combustion engines, gasoline For the majority of internal combustion engines, gasoline
(C8H18; four strokes Otto-cycle engines) serves as fuel.(C8H18; four strokes Otto-cycle engines) serves as fuel. Other sources like methane (CH4; gas turbines), diesel Other sources like methane (CH4; gas turbines), diesel
(mostly trucks) and kerosene (turbofans) are used.(mostly trucks) and kerosene (turbofans) are used. Perfect combustionPerfect combustion
If all internal combustion engines had perfect combustion, If all internal combustion engines had perfect combustion, emissions and thus environmental impacts of transportation emissions and thus environmental impacts of transportation would be negligible (except for carbon dioxide emissions).would be negligible (except for carbon dioxide emissions).
Combustion in internal combustion engines is imperfect and Combustion in internal combustion engines is imperfect and incomplete.incomplete.
A-4A-4
Combustion of Hydrocarbons
Chemical reactionChemical reaction Complete and perfect Complete and perfect
combustion of gasoline:combustion of gasoline: (2) C8H18 + (25) O2 = (16) CO2 (2) C8H18 + (25) O2 = (16) CO2
+ (18) H2O + energy+ (18) H2O + energy Gasoline produces around Gasoline produces around
46,000 Btu per kilogram 46,000 Btu per kilogram combusted.combusted.
Requires from 16 to 24 kg of air. Requires from 16 to 24 kg of air.
Gasoline
Oxygen
Carbon Dioxide
Water
Energy
Combustion
A-4A-4
Combustion of Hydrocarbons
Control or the processControl or the process Energy released by combustion causes a rise in temperature Energy released by combustion causes a rise in temperature
of the products of combustion.of the products of combustion. Temperature attained depends on the rate of release and Temperature attained depends on the rate of release and
dissipation of the energy and the quantity of combustion dissipation of the energy and the quantity of combustion products.products.
Air is the most available source of oxygen.Air is the most available source of oxygen. Air also contains vast quantities of nitrogen.Air also contains vast quantities of nitrogen. Nitrogen becomes the major constituent of the products of Nitrogen becomes the major constituent of the products of
combustion.combustion. Rate of combustion may be increased by finely dividing the Rate of combustion may be increased by finely dividing the
fuel to increase its surface area and hence its rate of reaction.fuel to increase its surface area and hence its rate of reaction. Mixing it with the air to provide the necessary amount of Mixing it with the air to provide the necessary amount of
oxygen to the fuel.oxygen to the fuel.
A-4A-4
Combustion of Hydrocarbons
Imperfect combustionImperfect combustion The fuel and the oxider are not The fuel and the oxider are not
pure.pure. Gasoline is known to have Gasoline is known to have
impuritiesimpurities Sulfur (0.1 to 5%).Sulfur (0.1 to 5%). Sometimes lead (anti-knock Sometimes lead (anti-knock
agent).agent). Other hydrocarbons (like Other hydrocarbons (like
benzene and butadiene).benzene and butadiene). Air is composed of 78% Air is composed of 78%
nitrogen and 21% oxygen. nitrogen and 21% oxygen.
GasolineSulfurBenzene
Air
Carbon Dioxide
Water
Energy
Combustion
NitrogenOxygen
Carbon monoxideNitrogenOxides
VOC + HC
A-4A-4
Combustion of Hydrocarbons
Consequences of incomplete combustionConsequences of incomplete combustion Incomplete combustion emits other residuals.Incomplete combustion emits other residuals. Because of the technology of the engine.Because of the technology of the engine. Besides carbon dioxide and water, a typical internal Besides carbon dioxide and water, a typical internal
combustion engine will produce:combustion engine will produce: Carbon monoxide (CO).Carbon monoxide (CO). Hydrocarbons (HC; benzene, formaldehyde, butadiene and Hydrocarbons (HC; benzene, formaldehyde, butadiene and
acetaldehyde).acetaldehyde). Volatile organic compounds (VOC).Volatile organic compounds (VOC). Sulfur dioxide (SO2), particulates, and nitrogen oxides Sulfur dioxide (SO2), particulates, and nitrogen oxides
(NOx).(NOx). These combustion products are the main pollutants emitted in These combustion products are the main pollutants emitted in
the environment by transportation. the environment by transportation.
A-4A-4
Transportation and Energy Consumption
IssueIssue Differences between speed, energy costs, mode and type of Differences between speed, energy costs, mode and type of
loads (freight and passengers).loads (freight and passengers). Economies of scale play a crucial role in freight transportationEconomies of scale play a crucial role in freight transportation
Transposed in its general levels of energy consumption.Transposed in its general levels of energy consumption. Transportation operators always ponder a compromise Transportation operators always ponder a compromise
between speed (returns in overcoming distance) and between speed (returns in overcoming distance) and energy (costs in overcoming distance).energy (costs in overcoming distance).
Lowest consumption levels are associated with bulk freight Lowest consumption levels are associated with bulk freight travelling at slow speed (like oil).travelling at slow speed (like oil).
Compromise of energy over speed.Compromise of energy over speed. High levels correspond to passengers or merchandises being High levels correspond to passengers or merchandises being
carried at high velocities.carried at high velocities. Compromise of speed over energy.Compromise of speed over energy.
A-5A-5
Transportation and Energy Consumption
.1
1
10
.01
.00210 30 100 300 1000
Speed (m/sec)
Tanker
Oil
Pipe
line
Truck
Cargo planeB
icyc
le
Bus
Train
Car
Helicopter
Propellerplane
Jetplane
Supersonicplane
Train
Freight
Passengers
Worst perf
orman
ce
Best p
erform
ance
Energ
y c
ost
s
Container ship
Gaspipeline
A-5A-5
Energy used by transportation
66%4%
1%
7%
5%
17%Vehicle operation
Vehicle maintenance
Vehicle manufacture
InfrastructureprovisionRaw materialmanufactureEnergy generation
A-5A-5
Transportation and Energy Consumption
CarCar Poor energetic performance.Poor energetic performance. Road transportation consumes 85% of the total energy used Road transportation consumes 85% of the total energy used
by the transport sector in developed countries.by the transport sector in developed countries. Only 12% of the fuel used by a car actually performs work.Only 12% of the fuel used by a car actually performs work. Exhaust (33%).Exhaust (33%). Cylinder cooling (29%).Cylinder cooling (29%). Engine friction (13%).Engine friction (13%). Transmission and axles (5.5%).Transmission and axles (5.5%). Braking (7.5%).Braking (7.5%).
A-5A-5
Factors of Fuel Use by Transportation
TechnologyVehicle efficiency
Type of fuel
EconomicsPrices and incomes
InfrastructureProvision and
Levels of service
Urban FormDensity and distribution
Fuel Use
A-5A-5
Typical Energy Use for a Car
12%
32%
29%
13%
6%
8%
Momentum
Exhaust
Cylinder cooling
Engine friction
Transmission and axles
Braking
A-5A-5
Average Gasoline Consumption for New Vehicles, United States, 1972-2001 (in miles per gallon)
10
12
14
16
18
20
22
24
26
28
30
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
Cars
Light Trucks
Average
A-5A-5
Light-Duty Vehicles Sales in the United States, 1975-2001 (in 1,000s)
0
2000
4000
6000
8000
10000
12000
14000
16000
18000Trucks
Cars
A-5A-5
Change in Average Vehicle Characteristics, 1981-2001 (in %)
-10
0
10
20
30
40
50
60
70
80
90
Fuel Economy Weight Horsepower Acceleration
A-5A-5
Average Miles per Gallon Traveled by Road Vehicle in the United States, 1996
0 10 20 30 40 50
Passenger cars
Motorcycles
Buses
Light trucks
Heavy trucks
Average
A-5A-5
Energy Consumption by Mode of Transportation in the United States (in Trillion BTU)
0
5,000
10,000
15,000
20,000
25,000
1970 1975 1980 1985 1990 1991 1992 1993 1994 1995 1996
Pipeline
Water
Rail
Transit
Road
Air
A-5A-5
Energy Consumption by Road Transportation in the United States (in Trillion BTU)
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
Bus
Combination Truck
Single-Unit 2-Axle 6-Tire orMore Truck
Other 2-Axle 4-Tire Vehicle
Passenger Car &Motorcycle
A-5A-5
Energy, Transportation and Urban Form
1. The Notion of Distance1. The Notion of Distance 2. Factors Affecting Distance Traveled2. Factors Affecting Distance Traveled
BB
Factors Affecting Distance Traveled
TrendsTrends The distance traveled has increased over the last 20 years in The distance traveled has increased over the last 20 years in
developed countries.developed countries. Predominantly in urban areas.Predominantly in urban areas.
VMT (VKT)VMT (VKT) Vehicle-Miles Traveled (or Vehicle-KM).Vehicle-Miles Traveled (or Vehicle-KM). Important measure of the usage of energy by transportation.Important measure of the usage of energy by transportation. Has increased 3% per year on average since 1970.Has increased 3% per year on average since 1970. Growth systematically higher than population growth and GDP Growth systematically higher than population growth and GDP
growth.growth. VMT growth has been linked to a set of factors.VMT growth has been linked to a set of factors.
A-1A-1
Factors Affecting VMT Growth
VMT
Population
Economic Activity
Spatial Structure
Vehicle Ownership
Age
Trip Length
Vehicle Occupancy
Cost of Driving
Alternatives available
A-1A-1
Factors Affecting Distance Traveled
Population and economic activityPopulation and economic activity Both a dominant factor.Both a dominant factor. Population growth is accompanied by an increase in urban Population growth is accompanied by an increase in urban
travel.travel. Economic activity, often expressed by GDP, is linked with Economic activity, often expressed by GDP, is linked with
increasing urban travel.increasing urban travel. Wealthier population can afford to travel more often and Wealthier population can afford to travel more often and
over longer distances.over longer distances. Increased consumption requires added deliveries of goods Increased consumption requires added deliveries of goods
and resources.and resources. Vehicle ownershipVehicle ownership
Access to a personal vehicle promotes its use.Access to a personal vehicle promotes its use. Correlated with the wealth of the population.Correlated with the wealth of the population. From 1969 to 1995, the number of vehicles per household has From 1969 to 1995, the number of vehicles per household has
increased from 1.2 to 1.8 in the United States.increased from 1.2 to 1.8 in the United States.
A-2A-2
Annual Growth Rates of VMT, Population and GDP, 1970-1995, United States
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
1970-75
1975-80
1980-85
1985-90
1990-95GDP
Population
VMT
A-2A-2
Changes in Population, GDP and VMT, 1969-1995, United States (1969=100)
100
120
140
160
180
200
220
240
1969 1977 1983 1990 1995
VMT
Population
GDP
A-2A-2
Factors Affecting Distance Traveled
Location of populationLocation of population Significant changes in the location of the population, notably in Significant changes in the location of the population, notably in
developed countries.developed countries. New spatial structures, such as sub-urbanization.New spatial structures, such as sub-urbanization. Lower average population densities.Lower average population densities.
Age of the populationAge of the population Strong correlation between age and mobility.Strong correlation between age and mobility. People over 65 are on average 40% less mobile than people People over 65 are on average 40% less mobile than people
between 35 and 54.between 35 and 54. Aging of population will slow VMT growth.Aging of population will slow VMT growth.
Trip lengthTrip length Correlated with locational changes in population.Correlated with locational changes in population. Longer distances between home and place of work.Longer distances between home and place of work.
A-2A-2
Annual VMT by Age Group and Gender, United States, 1995
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
16-19 20-34 35-54 55-65 65+
Males
Females
A-2A-2
Home-to-Work Commute Profile, United States, 1983-1995
8.510.6 11.6
18.219.7 20.7
28
32.333.6
0
5
10
15
20
25
30
35
40
1983 1990 1995
Average Length of WorkTrips (miles)
Average Work Trips TravelTime (minutes)
Average Speed (Miles perHour)
A-2A-2
Factors Affecting Distance Traveled
Vehicle OccupancyVehicle Occupancy Reflects the intensity of use of private and public urban Reflects the intensity of use of private and public urban
transportation.transportation. Dropped significantly in most developed countries.Dropped significantly in most developed countries. The most significant drop was for work-related trips.The most significant drop was for work-related trips.
Cost of drivingCost of driving Act as a deterrent.Act as a deterrent. Involve several costs such as car ownership, insurance, Involve several costs such as car ownership, insurance,
maintenance, taxes and fuel.maintenance, taxes and fuel. Have remained similar over the last 25 years.Have remained similar over the last 25 years.
Alternatives availableAlternatives available Involve public transit, walking, cycling, carpooling or working at Involve public transit, walking, cycling, carpooling or working at
home.home.
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Vehicle Occupancy by Purpose, 1977-1995, United States
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Social / Recreation
Family / Personal
Work
Average
1995
1977
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Alternative Sources of Energy for Urban Transportation
1. Context1. Context 2. Alternative Fuels2. Alternative Fuels
CC
Context
EmergenceEmergence Received increasing amounts of attention since the first oil Received increasing amounts of attention since the first oil
crisis in 1973.crisis in 1973. Attention ebbs and flows with fluctuations in the price of oil.Attention ebbs and flows with fluctuations in the price of oil. Several of alternate sources need further research before they Several of alternate sources need further research before they
can become truly viable alternatives.can become truly viable alternatives. Moving from carbon-based sources to non-carbon based.Moving from carbon-based sources to non-carbon based.
Unsustainability of fossil fuelsUnsustainability of fossil fuels The resource itself is finite; its use contributes to the global The resource itself is finite; its use contributes to the global
warming problem.warming problem. Some 35% of the carbon emissions in the USA is attributable Some 35% of the carbon emissions in the USA is attributable
to electric power generation.to electric power generation. Employing substitutes for fossil fuels in that area alone would Employing substitutes for fossil fuels in that area alone would
help alleviate our greenhouse gas problem.help alleviate our greenhouse gas problem.
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Context
Fuel use efficiencyFuel use efficiency Not an alternate energy source but can have a great impact on Not an alternate energy source but can have a great impact on
the conservation side of the ledger.the conservation side of the ledger. After 1973, many industries were motivated to achieve greater After 1973, many industries were motivated to achieve greater
efficiency of energy use.efficiency of energy use. Many appliances (including home air conditioners) were made Many appliances (including home air conditioners) were made
more energy efficient.more energy efficient. The motivation to do this declined during the 1980s with The motivation to do this declined during the 1980s with
declining energy costs.declining energy costs. The USA continually ranks behind Europe and Japan in The USA continually ranks behind Europe and Japan in
energy efficiency.energy efficiency. Contributes to our lack of competitiveness with those Contributes to our lack of competitiveness with those
economies.economies.
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Context
Besides electricity generation, another 32% of the carbon Besides electricity generation, another 32% of the carbon emissions in the USA is due to vehicular use.emissions in the USA is due to vehicular use.
More fuel-efficient cars would help reduce this amount.More fuel-efficient cars would help reduce this amount. Alternate energy sources, such as electricity, might make a Alternate energy sources, such as electricity, might make a
greater difference.greater difference. Require a great behavioral adjustment on the part of the car-Require a great behavioral adjustment on the part of the car-
using public, especially in the USA.using public, especially in the USA.
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Alternative Fuels
HydrogenHydrogen Considered in itself the cleanest fuel.Considered in itself the cleanest fuel. Compose 90% of the matter of the Compose 90% of the matter of the
universe.universe. Non polluting (emits only water and Non polluting (emits only water and
heat).heat). Highest level of energy content.Highest level of energy content.
Fuel cellsFuel cells Convert fuel energy (such as Convert fuel energy (such as
hydrogen) to electric energy.hydrogen) to electric energy. No combustion is involved.No combustion is involved. Composed of an anode and a Composed of an anode and a
cathode.cathode. Fuel is supplied to the anode.Fuel is supplied to the anode. Oxygen is supplied to the Oxygen is supplied to the
cathode.cathode. Electrons are stripped from a Electrons are stripped from a
reaction at the anode and reaction at the anode and attracted to form another attracted to form another reaction at the cathode.reaction at the cathode.
Hydrogen
Water Electricity
Fuel Cell
Fuel
Oxygen
Catalytic conversion
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Alternative Fuels
Fuel cell carsFuel cell cars Most likely replacement for the internal combustion engine.Most likely replacement for the internal combustion engine. Efficiency levels are between 55% and 65%.Efficiency levels are between 55% and 65%.
Where to get the hydrogen from?Where to get the hydrogen from? Not naturally occurring.Not naturally occurring. Electrolization of water.Electrolization of water.
Electricity from fossil fuels not a environmentally sound Electricity from fossil fuels not a environmentally sound alternative.alternative.
Electricity from solar or wind energy is a better alternative.Electricity from solar or wind energy is a better alternative. Extraction from fossil fuels.Extraction from fossil fuels.
From natural gas.From natural gas.
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