Movements are linked to specific urban activities and their land use. Each type of land use involves the generation and attraction of a particular array of movements. This relationship is complex, but is linked to factors such as recurrence, income, urban form, spatial accumulation, level of development and technology. Urban movements are either obligatory, when they are linked to scheduled activities (such as home-to-work movements), or voluntary, when those generating it are free to decide of their scheduling (such as leisure). The most common types of urban movements are:
- Pendular movements. These are obligatory movements involving commuting between locations of residence and work. They are highly cyclical since they are predictable and recurring on a regular basis, most of the time a daily occurrence, thus the term pendulum.
- Professional movements. These are movements linked to professional, work-based, activities such as meetings and customer services, dominantly taking place during work hours.
- Personal movements. These are voluntary movements linked to the location of commercial activities, which includes shopping and recreation.
- Touristic movements. Important for cities having historical and recreational features they involve interactions between landmarks and amenities such as hotels and restaurants. They tend to be seasonal in nature or occurring at specific moments. Major sport events such as the World Cup or the Olympics are important generators of urban movements during their occurrence.
- Distribution movements. These are concerned with the distribution of freight to satisfy consumption and manufacturing requirements. They are linked to distribution centers and retail outlets.
The consideration of urban movements involves their generation, the modes and routes used and their destination:
- Trip generation. On average, an urban resident undertakes between 3 and 4 trips per day. Moving in an urban area is usually done to satisfy a purpose such as employment, leisure or access to goods and services. Each time a purpose is satisfied, a trip is generated. Important temporal variations of the number of trips by purpose are observed.
- Modal split. Implies which transportation mode is used for urban trips and is the outcome of a modal choice. Modal choice depends on a number of factors such as technology, availability, preference, travel time and income.
- Trip assignment. Involves which routes will be used for journeys within the city. For instance, a commuter driving a car has most of the time a fixed route. This route may be modified if there is congestion or if another activity (such as shopping) is linked with that trip; often known as trip chaining. Several factors influence trip assignment, the two most important being transport costs and availability.
- Trip destination. Changes in the spatial distribution of economic activities in urban areas have caused important modifications to the destination of movements, notably those related to work. The central city used to be a major destination for movements, but its share has substantially declined in most areas and suburbs now account for the bulk of urban movements.
And some interesting data from that section:
Urban Travel by Purpose and by Time of the Day
(Source)Destination for Work-Related Movements in the United States
(Source)Main Purposes of Urban Trips
(Source)Modal Split for Global Cities, 1995
(Source)
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