Screen line checks
- Screen line survey refers to volume count conducted at different locations in the study area at crossings along natural barriers like rivers, canals and railway lines.
- The main purpose of this survey is validation of models developed.
- Based on house interview survey, trip assignments are made which would give the volume of traffic on different routes, from which the trips going across the screen lines can be determined.
- This is cross checked with the data on counts made at the screen line locations and adjustments in calibration of the model can be made.
Cordon line checks
- The imaginary line representing the boundary of the study area is termed as the ‘cordon line’.
- The area inside the external cordon line determines the travel pattern.
- The data collected from internal to external, external to internal, and external to external movements.
- The data collected at selected cordon points are useful for data adjustment.
