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Now a days, traffic simulation packages like CORSIM and VISSIM are frequently
used as tools for analyzing traffic.
VISSIM is a microscopic, time step and behaviour based simulation model
developed to analyze the full range of functionally classified roadways and
public transportation operations.
Since all these are commercial software packages, it is not possible to make
sufficient changes in the internal parameters used in these models according to
the specific requirements.
Common applications of these packages include freeway and arterial corridor
studies, sub-area planning studies, evacuation planning, freeway management
strategy development, environmental impact studies, Intelligent Transportation
Systems (ITS) assessments, current and future traffic management schemes etc.
Results of simulation can be interpreted in different ways.
Animation displays of extracting the sought information and insights from the
mass of the traffic environment (if available) are a most powerful tool for
analyzing simulation results.
If the selected traffic simulation lacks an animation feature or if questions
remain after viewing the animation, then the following procedures may be
adopted:
- Execute the model to replicate existing real-world conditions and compare
its results with observed behaviour.
This "face validation" can be done to identify model or implementation
deficiencies.
- Perform "sensitivity" tests on the study network by varying key variables
and observing model responses in a carefully designed succession of model
executions.
- Plot these results. A review will probably uncover the perceived
anomalies
Statistical analysis of the simulation results are also conducted to present
point estimates of effectiveness and to form the confidence intervals.
Through these processes, one can establish that which simulation system is the
best among the different alternatives.
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