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Question 1

What is travel demand?

Answer 1

The number of persons or vehicles per unit time expected to travel on a given segment of a transportation system under specific conditions

Question 2

What are the methods for forecasting travel demand?

Answer 2

Methods range from simple extrapolation of observed trends to sophisticated computerized processes involving extensive data gathering and mathematical modeling

Question 3

What are the two basic demand forecasting situations in transportation planning?

Answer 3

• Urban Travel Demand Forecast
• Intercity Travel Demand

Question 4

What information was required for urban travel demand forecasts developed in the 1950s and 1960s?

Answer 4

Extensive databases using home interview and/or roadside interview surveys

Question 5

What are the three factors influencing urban travel demand?

Answer 5

• Location and intensity of land use
• Socioeconomic characteristics of people
• Extent, cost, and quality of available transportation services

Question 6

How do land-use characteristics affect travel demand?

Answer 6

The amount of traffic generated depends on how the land is used, e.g., shopping centers vs. residential complexes

Question 7

How do socioeconomic characteristics influence travel demand?

Answer 7

Lifestyles and values affect transportation resource decisions, with high-income areas generating more auto trips

Question 8

What is the role of transportation facilities in travel demand?

Answer 8

Availability of transportation facilities and services (supply) affects demand; travelers consider service levels when choosing modes

Question 9

What is the purpose of travel demand forecasting in urban transportation planning?

Answer 9

To predict travel behavior and resulting demand for a specific future time frame based on land use, trip makers, and transportation system nature

Question 10

Why is understanding existing travel patterns important in transportation planning?

Answer 10

It helps identify traffic-related problems and develop forecasting models

Question 11

What are the five characteristics of travel?

Answer 11

• Functional classification
• System extent
• System usage
• System performance/capacity
• System condition

Question 12

How is travel demand measured?

Answer 12

In different ways for different analyses, including:
* Trip
* Trip end
* Traffic volume
* Person trip and vehicle trip
* Passenger vehicle and freight vehicle
* Person-mile traveled and vehicle-mile traveled

Question 13

What is the significance of the time frame for travel surveys?

Answer 13

Travel demand varies seasonally and weekly, necessitating careful selection of survey time frames

Question 14

What are Origin-Destination (O-D) surveys used for?

Answer 14

To classify trips into internal, external-internal, and through trips for forecasting and policy development

Question 15

What is traffic forecasting?

Answer 15

Estimating the number of vehicles or people that will use a specific transportation facility in the future

Question 16

What are the four steps of travel demand forecasting?

Answer 16

• Trip Generation
• Trip Distribution
• Modal Split
• Traffic Assignment

Question 17

What is trip generation?

Answer 17

The first step in the four-step modeling procedure that establishes the total number of trips generated in a study area

Question 18

What is trip distribution?

Answer 18

Allocating trip ends from the generation model to specific origins and destinations using transportation network characteristics

Question 19

What is modal split?

Answer 19

The percentage of travelers using a specific mode of transport compared to all trips made

Question 20

What does travel assignment estimate?

Answer 20

The volumes on the transportation system, including present-day and forecasted volumes

Question 21

What is the Origin-Destination (OD) Matrix?

Answer 21

A table that summarizes the number of trips generated and attracted between defined zones

Question 22

What methods can be used for estimating trip generation?

Answer 22

• Growth rate method
• Category analysis
• Regression model

Question 23

What is the Gravity Model in trip distribution?

Answer 23

A method where trips are proportional to the number of trips produced and attracted by each zone and inversely proportional to the distance between zones

Question 24

What is the generalized cost in modal split?

Answer 24

A method that quantifies both quantifiable and unquantifiable costs incurred during a trip using a specified mode

Question 25

What is the disaggregate choice model?

Answer 25

A method assuming a person will use the mode offering maximum utility

Question 26

What is the utility function for travel in a medium-sized city by car, bus, and light rail?

Answer 26

U = A -0.02X1 – 0.05X2 ## Footnote Where X1 is the cost of travel in pesos and X2 is the travel time (min).

Question 27

What happens to the share of car users when a parking fee of P30 per trip is imposed?

Answer 27

The share of car is reduced from 36 percent to 24 percent, resulting in a shift to bus and rail with increased shares of 32 percent and 44 percent, respectively.

Question 28

List the factors that affect modal split.

Answer 28

* Characteristics of the trip maker * Characteristics of the journey * Characteristics of the transport facility

Question 29

What is the primary assumption in traffic assignment regarding route choice?

Answer 29

Car drivers will use the route or routes that allow them to reach their destination in the least time or distance.

Question 30

What are the basic components used to represent a road network?

Answer 30

* Nodes (representing zone centroids) * Links (representing roads connecting the zones)

Question 31

What is the prerequisite for route assignment in traffic assignment?

Answer 31

Determination of the shortest path from one node to another.

Question 32

What algorithm is commonly used to find the shortest path in a road network?

Answer 32

Dijkstra’s algorithm.

Question 33

Describe the first step of Dijkstra’s algorithm.

Answer 33

Label the starting node with a value equal to 0, which is permanent.

Question 34

In Dijkstra’s algorithm, how are temporary labels assigned?

Answer 34

Adjacent unlabelled nodes are given a label equal to the weight of the link plus the value of the previously labelled node.

Question 35

What is the outcome once the final node has a permanent label in Dijkstra’s algorithm?

Answer 35

The shortest path has a length given by its permanent value.

Question 36

What is the all-or-nothing assignment method?

Answer 36

All trips are assigned to the shortest path from the point of origin to the point of destination.

Question 37

What is the basic process for conducting an all-or-nothing assignment?

Answer 37

* Find the minimum path between zones * Assign all trips with the minimum path * Repeat for all OD pairs

Question 38

What does the constant assignment ratio method assume?

Answer 38

The number of trips assigned to a route is inversely proportional to the travel time or cost of that route.

Question 39

List the basic steps for the constant assignment ratio method.

Answer 39

* Find possible routes between zones * Calculate the level of service on each route * Distribute trips inversely proportional to LOS

Question 40

What principle does the incremental assignment method rely on?

Answer 40

Wardrop’s Principle, which states that routes used have equal level of service.

Question 41

What are the steps involved in the incremental assignment method?

Answer 41

* Assign 1/n of the trips to a route * Calculate the new level of service * Assign the next 1/n trips * Repeat until all trips are assigned

Question 42

List the factors that affect traffic assignment.

Answer 42

* Speed limit * Number of lanes * Length of road * Density of intersection * Time of travel