Task 2 Data Collection and Analysis of the Existing Urban Transport Environment

Task 2-4 Transport Demand Surveys

Traffic demand data such as traffic volume and origin-destination (O-D) data are essential for urban transport planning. The following surveys should be carried out.

(1) Collection of Transport Demand Data

Information such as population and employment distribution, is essential in transport demand modelling. This type of information relates to the land use pattern of the metropolitan area. The following data (Table 7) should be collected.

Table 7 Survey Items for Transport Demand Data

Survey Items Description Sample Form
Population and Socio-Economic Conditions Collect population and socio-economic indices by zone, which should be as small as possible. Zones may consist of one or more census districts. Survey Form 2-1A
Vehicle Ownership Survey Collect vehicle ownership data for the same zones as above. Survey Form 2-1B

(2) Traffic Volume Surveys

Traffic volumes should be inventoried on all major roads by reference to existing traffic counts and by new surveys. Since traffic data are also necessary for developing and calibrating a transport demand model as well as updating it, the survey should not be conducted on an ad hoc basis, but systematically. Required traffic surveys are described in Table 8 and the concepts of screen-line and cordon-line surveys are shown in Figure 8.

Table 8 Survey Items for Traffic Volume Surveys

Survey Items Description Sample Form
Screen Line Survey (optional) A screen line survey identifies major traffic movements between two areas divided by a screen line such as a river or railway. Survey Form 2-2A
Cordon Survey A cordon survey is a traffic count survey on a major cordon line that shows the volume of traffic entering/departing a target area or a city centre. Survey Form 2-2A
Intersection Turning Movement Survey Measures turning movements at key intersections during the morning and evening peak hours. Survey Form 2-2B
Queue Length Survey A queue length survey at major bottlenecks can show the severity of traffic congestion quantitatively Survey Form 2-2C
Travel Speed and Time Survey Conduct travel speed and time surveys on main corridors and strategically important roads in order to assess the efficiency of the road network at both peak and off-peak times. Survey Form 2-2D

Figure 8 Concept of Screen Line Survey and Cordon Line Survey
Figure 8 Concept of Screen Line Survey and Cordon Line Survey

(3) Implementation of an Origin-Destination (O-D) Survey

O-D surveys to establish travel patterns (where people are moving to/from) can be carried out by a household interview survey, a commercial vehicle survey and a roadside interview survey. The results of these surveys are used to develop O-D matrices, to calibrate a transport demand model (Annex 4 describes the tasks involved in the four step transport demand modelling).

Household and roadside O-D surveys should be conducted. Table 9 summarizes the characteristics of these surveys.

Table 9 Outline of Origin-Destination Survey

  Household O-D Survey Roadside O-D Survey
Objective To identify the travel activities of residents. To clarify the travel movements between locations outside and inside the metropolitan area.
Methodology Interview survey of each household. Interview survey of drivers on target roads.
Survey Area and The whole CMP target area. On major roads on the border of the target area (the same as the cordon line traffic count survey).
Zoning The survey zones should basically follow the census district pattern. A zone may consist of one or more census districts. Zoning should be consistent with that in the household O-D survey.
Questionnaire Forms Survey Form 2-3A(1) and (2) Survey Form 2-3B
Sampling Rate A sampling rate of 4% in each zone is preferable. If there are significant time and cost constraints, the sample rate may be reduced to 1%. A sampling rate of 20% of all traffic on the road is recommended. The rate can be reduced on roads with heavy traffic.

(4) Implementation of a Traffic Movement Survey

To complement the above surveys, the survey shown in Table 10 should also be conducted.

Table 10 Outline of Traffic Movement Survey

  Public Transport Vehicle Movement Survey Freight Vehicle Movement Survey
Objective To identify the travel movements of buses, taxis and rickshaws To identify truck movements
Methodology Interview survey of public transport vehicle drivers, including drivers of buses and rickshaws Interview survey of truck drivers
Questionnaire Forms Survey Form 2-4A Survey Form 2-4A
Sampling Rate A sampling rate equal to 20% of the total number of registered vehicles is preferable. A sampling rate equal to 20% of the total number of registered vehicles is preferable.

(5) Development of Base-Year Transport Demand Model

In the CMP preparation process, transport demand modelling is used to analyse/evaluate urban land use and the transport system. The modelling technique provides a quantitative and scientific approach to improving mobility. The CMP modelling technique emphasizes person-based travel patterns, along with vehicle movements. It includes more NMV/pedestrian movements than conventional modelling approaches. It also enables integrated planning of urban land use and the transport system.

In this task, a base-year demand model will be developed by using the results of the O-D survey. Key steps in the demand modelling are elaborated in Annex 4.

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