Transportation Engineering Topic 4

Front

What is travel demand forecasting?

Back

Travel demand forecasting is the process of estimating the number of persons or vehicles expected to travel on a given segment of a transportation system under specific land-use, socioeconomic, and environmental conditions.

Front

What are the two basic types of travel demand forecasting?

Back

1. Urban travel demand forecasts - involve data concerning the travel maker such as age, sex, income, vehicle ownership, etc. 2. Intercity travel demand forecasts - involve city population, average city income, travel time, or travel cost between city pairs.

Front

What are the three factors that influence urban travel demand?

Back

1. Land use characteristics 2. Socioeconomic characteristics 3. Availability of transportation services.

Front

How do land-use characteristics affect travel demand?

Back

The amount of traffic generated by a parcel of land depends on how the land is used, with different types of land (e.g., shopping centers, residential complexes) producing different traffic generation patterns.

Front

How do socioeconomic characteristics influence travel demand?

Back

Socioeconomic characteristics, such as income and lifestyle, affect how people decide to use their resources for transportation, impacting the number of trips generated.

Front

What is a traffic analysis zone (TAZ)?

Back

A traffic analysis zone (TAZ) is an area selected for study in transport planning models, characterized by homogeneous socioeconomic characteristics and specific criteria for population and trip generation.

Front

What are the criteria for establishing a traffic analysis zone (TAZ)?

Back

1. Socioeconomic characteristics should be homogeneous. 2. Intrazonal trips should be minimized. 3. Zones must have under 3,000 people. 4. Zones should not be created within other zones. 5. The zone system should generate and attract approximately equal trips. 6. Zones with very large area or low trips are discarded. 7. TAZ boundaries must adjust according to political, administrative, or statistical boundaries.

Front

What is the four-step travel demand model?

Back

The four-step travel demand model consists of trip generation, trip distribution, modal choice, and traffic assignment.

Front

What is trip generation?

Back

Trip generation is the process of determining the number of trips that will begin or end in each traffic analysis zone within a study area.

Front

What are the two types of trips in trip generation?

Back

1. Home-based trips - trips originated or destined at home. 2. Non-home based trips - trips originated or destined neither at home.