Activity-Based Traffic Demand Using ActivityGen
Activity-based demand generation follows a simple idea: Traffic originates from persons who travel to another location for an intended activity – like sports, work or shopping. As a consequence, the following two steps are performed to generated activity-based demand: A synthetic population is placed into the network (resulting in the persons). Then, activities are assigned to the persons of this population. These activities finally result in traffic.
SUMO provides ActivityGen to generate activity-based demand. It takes the network together with a description of the population and produces a route file.
Contents |
Activities
ActivityGen takes into account two groups of activities, which are considered as most traffic-relevant: Work And School and Free Time. The activities within each group follow the same statistical rules.
Work and School Activities
This aggregate of activities contains the following activities:
- Going to work for adults (not retired), and
- Going to school for children.
That implies trips from home to work and the return trip for the drivers.
Free Time Activities
This aggregate of activities contains the following activities:
- Going out during the day (for retired or unemployed people)
- Going out in the evening (for all people who finished their work activity not too late)
- Going out late in the evening or in the night (for not retired adults having no children)
This activity is supposed to cover all car uses for:
- Going out see friends
- Doing sport
- Visiting family
- Party
Transportation Means
The population is distributed according to the statistics into households located in streets. People are likely to use different means of transportation in relation to their location, the availability of the different means and their destination. Three kind of Means are used in ActivityGen:
- Feet or bike
- Buses
- Cars
All of them have their own possibilities and availability characteristics:
Feet or Bike
Trips by foot are available only for very short distances. But in this case, the person is very likely to go by foot. The bike isn't really used (buses and cars are preferred), it is supposed to serve in cases where none of the three means (Feet, buses and cars) are not available
Buses
Bus stations are located in the city corresponding to the real bus line network given in input (statistical data over the city). Someone enough close to a bus station and whose destination is enough close to another bus station is eligible for the public transportation means.
Cars
Householders having one or more cars can drive (not children) or be accompanied (escorted) by another adult who needs a car too. Children can only be accompanied (to school for example). Some households have no car, in this case they have to live enough close to a bus station. In the case of having a destination far from any bus station, they can go by foot or ride a bike. But this case doesn't generated any motorized vehicle traffic.
Input statistics
First of all we need general information over the city.
<city>
<general
inhabitants="1000"
households="500"
childrenAgeLimit="18"
retirementAgeLimit="65"
carRate="0.58"
unemploymentRate="0.05"
footDistanceLimit="350"
incomingTraffic="200"
outgoingTraffic="50"
/>
</city>
The meanings of all these attributes are described in the following table:
| Attribute Name | Mandatory | Value Type | Description |
|---|---|---|---|
| inhabitants | yes | Integer | Total number of inhabitants |
| households | yes | Integer | Total number of households (must be between 0.5 and 1 times the number of adults of the city) |
| childrenAgeLimit | yes | Integer | Age under which people are children. This is the first year of adulthood |
| retirementAgeLimit | yes | Integer | Age under which people can have children home and work |
| carRate | yes | Float[0;1] | Probability for an adult to own a car |
| unemploymentRate | yes | Float[0;1] | Probability for an adult in age of work to be unemployed |
| footDistanceLimit | yes | Integer | Maximum distance one would go by foot instead of another transportation mean. |
| incomingTraffic | yes | Integer | Number of people coming everyday into the city for they work |
| outgoingTraffic | yes | Integer[0,inhabitants] | Number of inhabitants working outside the city |