transport and the urban environment topic 2 – urban transportation and energy a – transportation...

Transport and the Urban EnvironmentTransport and the Urban Environment

Topic 2 – Urban Transportation and Energy

A – Transportation and Energy ConsumptionA – Transportation and Energy Consumption

B – Energy, Transportation and Urban FormB – Energy, Transportation and Urban Form

C – Alternative Sources of Energy for Urban C – Alternative Sources of Energy for Urban TransportationTransportation

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 Human activities are closely dependant to the usage of several

forms and sources of energy.forms 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 exists in various formsEnergy exists in various forms Mechanical, thermal, chemical, electrical, radiant, and Mechanical, thermal, chemical, electrical, radiant, and

atomic and are all interconvertible.atomic 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-so high that biomass may be considered as a non-renewable source in those circumstances.renewable 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 Currently favoring the usage of fossil fuels, notably

petroleum.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.


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 Modifies products from the biomass, raw materials and

goods to manufacture according to economic needs.goods 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).

A-1A-1


TransferTransfer Movements of freight, people and information from one Movements of freight, people and information from one

place to another.place to another. Attenuate the spatial inequities in the location of resources Attenuate the spatial inequities in the location of resources

by overcoming distance.by 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 Work related to transfers of goods, people and information

has increased significantly.has 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


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 Transportation accounts for about 24% of all the energy

used in the United States.used in the United States.

A-1A-1

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

A-1A-1

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


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.

A-1A-1


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 storability, flexibility, safety and cleanliness of high energy content sources for a low price.energy 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.

A-1A-1

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 Favor the usage of petroleum as the main source of energy

for transport activities.for 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 Exploitation of oil fields in several regions of the World

(Middle East, Siberia, etc.).(Middle 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 Most petroleum products are in a liquid, more or less

viscous, form.viscous, 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 A low energy content is inadequate when demand is high

and concentrated in space.and 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 An energy source has an advantage when it can be stored

to answer variations in demands and interruptions of to answer variations in demands and interruptions of supplies. 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, Synthesize goods like plastics, pharmaceutical products,

and synthetic rubber.and 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 Oil is considered a safe source of energy for its production

and usage.and usage. CleanlinessCleanliness

Sources that produce few waste and are cleanly used have Sources that produce few waste and are cleanly used have an advantage.an advantage.

In regards of other conventional energy sources like coal In regards of other conventional energy sources like coal and wood and of the available technology, oil is cleaner to and wood and of the available technology, oil is cleaner to use and produces a limited amount of waste. use and 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 A function of the occurrence, the transferability and the

energy content of the source.energy 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 Petroleum products account for more than 97% of the

energy consumption by transportation modes.energy 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 Since 1973 the price of petroleum has increased

significantly.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


Chemical reactionChemical reaction Complete and perfect Complete and perfect

combustion of gasoline:combustion of gasoline: (2) C8H18 + (25) O2 = (16) (2) C8H18 + (25) O2 = (16)

CO2 + (18) H2O + energyCO2 + (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 Requires from 16 to 24 kg of air. air.

Gasoline

Oxygen

Carbon Dioxide

Water

Energy

Combustion

A-4A-4


Control or the processControl or the process Energy released by combustion causes a rise in Energy released by combustion causes a rise in

temperature of the products of combustion.temperature 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 fuel to increase its surface area and hence its rate of reaction.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


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-Sometimes lead (anti-

knock agent).knock 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


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 Hydrocarbons (HC; benzene, formaldehyde, butadiene

and acetaldehyde).and 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 These combustion products are the main pollutants emitted

in the environment by transportation. in the environment by transportation.

A-4A-4


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 Economies of scale play a crucial role in freight

transportationtransportation 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 High levels correspond to passengers or merchandises

being carried at high velocities.being carried at high velocities. Compromise of speed over energy.Compromise of speed over energy.

A-5A-5


.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


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 The distance traveled has increased over the last 20 years

in developed countries.in 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 Growth systematically higher than population growth and

GDP growth.GDP 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


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 Increased consumption requires added deliveries of

goods and resources.goods 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 From 1969 to 1995, the number of vehicles per household

has increased from 1.2 to 1.8 in the United States.has 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


Location of populationLocation of population Significant changes in the location of the population, notably Significant changes in the location of the population, notably

in developed countries.in 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


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 Involve public transit, walking, cycling, carpooling or working

at home.at home.

A-2A-2

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

A-2A-2

Alternative Sources of Energy for Urban Transportation

1. Context1. Context 2. Alternative Fuels2. Alternative Fuels

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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 Several of alternate sources need further research before

they can become truly viable alternatives.they 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 Some 35% of the carbon emissions in the USA is

attributable to electric power generation.attributable to electric power generation. Employing substitutes for fossil fuels in that area alone Employing substitutes for fossil fuels in that area alone

would help alleviate our greenhouse gas problem.would 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 Not an alternate energy source but can have a great impact

on the conservation side of the ledger.on the conservation side of the ledger. After 1973, many industries were motivated to achieve After 1973, many industries were motivated to achieve

greater efficiency of energy use.greater efficiency of energy use. Many appliances (including home air conditioners) were Many appliances (including home air conditioners) were

made more energy efficient.made 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 Considered in itself the cleanest

fuel.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%. May be introduced by 2004.May be introduced by 2004.

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 Electricity from solar or wind energy is a better alternative.alternative.

Extraction from fossil fuels.Extraction from fossil fuels. From natural gas.From natural gas.

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transport and the urban environment topic 2 – urban transportation and energy a – transportation...

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energy source u

u forms of energy

usage of energy

energy consumption b

energy consumption n

mechanical energy

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work u