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Topic 6 – Urban Transportation Transportation and Urban Form Urban Land Use and Transportation Urban Mobility Urban Transport Problems
C – Urban Mobility • 1. Urban Movements • 2. Urban Transit
1. Urban Movements • Land use • Specific movements are linked to specific urban activities and their land use. • Involves the generation and attraction of an explicit array of movements. • Factors: • Recurrence, income, urban form, spatial accumulation, level of development and technology. • Urban movements • Obligatory: linked to scheduled activities (such as home-to-work movements) • Voluntary: free to decide of their scheduling (such as leisure).
Typical Urban Day Trips by Modes, Origins and Destinations 10:45 PM Return 1:30 AM Delivery 10:30 PM Delivery Shopping mall 2:30 AM Return Restaurant 8:30 PM Drive alone 1:30 PM Walk 7:00 PM Drive alone 5:30 PM Drive alone Home Work 12:30 PM Walk 7:00 AM Garbage pickup 8:15 AM Drive alone 8:00 AM Carpool 10:00AM Parcel Drop off Passengers 10:05AM Parcel Pickup School (drop off child) Freight
Urban Travel by Purpose and by Time of the Day in a North American Metropolis
2. Urban Transit • Context • Dominantly an urban transportation mode. • The great majority of transit trips are taking place in large cities. • Conditions fundamental to the efficiency of transit systems: • High density and high mobility demands over short distances. • Shared public service: • Benefits from economies of agglomeration related to high densities. • Economies of scale related to high mobility demands. • Transit systems • Many types of services established to answer mobility needs. • Variety of transit systems around the world.
Private Vehicle and Public Transport Market Share, 1990/91 American Cities European Cities Asian Cities
2. Urban Transit • Metro system • Heavy rail system, often underground in central areas, with fixed routes, services and stations. • Uniform frequency of services (peak hours increase). • Fares are commonly access driven and constant. • Bus system • Scheduled fixed routes and stops serviced by motorized multiple passengers vehicles (45 - 80 passengers). • Services are often synchronized with other heavy systems (feeders). • Express services (notably during peak hours). • Transit rail system • Fixed rail (tram rail system and commuter rail system) • Frequency of services strongly linked with peak hours. • Traffic tends to be imbalanced. • Separate fares and proportional to distance or service zones.
Largest Subway Systems in the World by Annual Ridership and Metropolitan Population, 2000
2. Urban Transit • Shuttle system • Privately (dominantly) owned using small buses or vans. • Routes and frequencies tend to be fixed (can be adapted). • Service numerous specific functions: • Expanding mobility along a corridor during peak hour. • Linking a specific activity center (shopping mall, university campus, industrial zone, hotel, etc.). • Servicing the elderly or people with disabilities. • Paratransit system • Flexible and privately owned demand-response system: • Minibuses, vans or shared taxis. • Commonly servicing peripheral and low density zones. • Door-to-door service, less loading and unloading time, less stops and more maneuverability in traffic.
2. Urban Transit • Taxi system • Privately owned cars or small vans offering an on-call, individual demand-response system. • Fares: • Commonly a function of a metered distance/time. • Can be negotiated. • When competition is not permitted, fares are set up by regulations. • No fixed routes: • Servicing an area where a taxi company has the right (permit) to pickup customers. • Rights are issued by a municipality. • Several companies may be allowed to compete on the same territory.
Components of an Urban Transit System X X X X X X X X X X X X X X X X X X X X X X X Metro station Transit rail station Bus stop Paratransit Shuttle stop Taxi service boundary X Express stop Transfer
D – Urban Transport Problems • 1. Geographical Challenges Facing Urban Transportation • 2. Automobile Dependency • 3. Congestion
1. Geographical Challenges Facing Urban Transportation • Context • Most important transport problems often related to urban areas. • Urban productivity: • Dependent on the efficiency of its transport system. • Move labor, consumers and freight between several origins and destinations. • Growing complexity of cities: • Accompanied by a wide array of urban transportation problems. • Some problems are ancient like congestion (Rome). • Others are new like environmental impacts: • Notably CO2 emissions linked with the diffusion of the internal combustion engine.
1. Geographical Challenges Facing Urban Transportation • Traffic congestion and parking difficulties. • Public transport crowding and off-peak inadequacy. • Difficulties for pedestrians. • Environmental impacts and energy consumption. • Accidents and safety. • Land consumption. • Freight distribution.
2. Automobile Dependency • Causes • Advantages of automobile use: • Performance, comfort, status, speed, and convenience. • Illustrate why car ownership continues to grow worldwide. • Factors of growth: • Sustained economic growth (increase in revenue and quality of life). • Complex individual urban movement patterns. • Peripheral urban growth. • Factors of dependency • Underpricing and consumer choices: • Most road infrastructures are subsidized (considered a public service). • Drivers do not bear the full cost of car usage. • Car ownership is a symbol of status • Single home ownership.
2. Automobile Dependency • Planning and investment practices: • Aims towards improving road and parking facilities in an ongoing attempt to avoid congestion. • Transportation alternatives tend to be disregarded. • In many cases, zoning regulations impose minimum standards of road and parking services and de facto impose a regulated car dependency.
3. Congestion • Congestion • Occurs when transport demand exceeds transport supply in a specific section of the transport system. • Each vehicle impairs the mobility of others. • Types: • Recurring congestion (specific times of the day and on specific segments of the transport system). • Random events (accidents and weather conditions).
Recurring Congestion Unused Capacity
The Vicious Circle of Congestion Congestion Public pressures to increase capacity The number of movements increases New capacity The average length of movements increases Movements are more easy Urban sprawl is favored
Total Traffic Delay in Selected American Cities, 1986-1990 (in 1,000 hours per day)
3. Congestion • Ramp metering • Controlling access to a congested highway by letting automobiles in one at a time instead of in groups. • Traffic signal synchronization • Tuning the traffic signals to the time and direction of traffic flows. • Incident management • Making sure that vehicles involved in accidents or mechanical failures are removed as quickly as possible from the road. • HOV (High Occupancy Vehicle) lanes • Vehicles with 2 or more passengers (buses, vans, carpool, etc.) have exclusive access to a less congested lane. • Public transit • Offering alternatives to driving.