PPT: Microscopic Traffic Modeling | Transportation Engineering - Civil Engineering (CE) PDF Download

 Page 1


Microscopic
Traffic Modeling
Page 2


Microscopic
Traffic Modeling
Traffic model classification Traffic model classification ( (1 1) )
nn Static Static
– – Models average steady Models average steady- -state traffic situation state traffic situation
nn Dynamic Dynamic
– – Models Models changes over time changes over time of the traffic situation of the traffic situation
7:00 10:00 15:00 18:00
Dynamic
Static
Page 3


Microscopic
Traffic Modeling
Traffic model classification Traffic model classification ( (1 1) )
nn Static Static
– – Models average steady Models average steady- -state traffic situation state traffic situation
nn Dynamic Dynamic
– – Models Models changes over time changes over time of the traffic situation of the traffic situation
7:00 10:00 15:00 18:00
Dynamic
Static
raffic model classification ( Traffic model classification (2 2) )
nn Different levels of detail in Different levels of detail in simulation simulation
models: models:
–– Macroscopic: Macroscopic:
» » Like water flowing through a pipe Like water flowing through a pipe
–– Mesoscopic Mesoscopic
» » Individual vehicles with aggregate behaviour Individual vehicles with aggregate behaviour
–– Microscopic Microscopic
» » Individual vehicles with detailed behaviour Individual vehicles with detailed behaviour
Page 4


Microscopic
Traffic Modeling
Traffic model classification Traffic model classification ( (1 1) )
nn Static Static
– – Models average steady Models average steady- -state traffic situation state traffic situation
nn Dynamic Dynamic
– – Models Models changes over time changes over time of the traffic situation of the traffic situation
7:00 10:00 15:00 18:00
Dynamic
Static
raffic model classification ( Traffic model classification (2 2) )
nn Different levels of detail in Different levels of detail in simulation simulation
models: models:
–– Macroscopic: Macroscopic:
» » Like water flowing through a pipe Like water flowing through a pipe
–– Mesoscopic Mesoscopic
» » Individual vehicles with aggregate behaviour Individual vehicles with aggregate behaviour
–– Microscopic Microscopic
» » Individual vehicles with detailed behaviour Individual vehicles with detailed behaviour
raffic model classification ( Traffic model classification (3 3) )
nn Other dimensions: Other dimensions:
–– Stochastic or Deterministic Stochastic or Deterministic::
»» stochastic stochastic modelling captures variation in e.g. modelling captures variation in e.g.
reaction time, arrival processes, route choice. reaction time, arrival processes, route choice. But But
every simulation run results in different outcome, so every simulation run results in different outcome, so
you need to you need to replicate simulation runs replicate simulation runs
–– Time Time- -stepped or event stepped or event- -based: based:
»» Time stepped Time stepped: the model calculates the changes in : the model calculates the changes in
the system for finite steps (e.g. the system for finite steps (e.g. 1 1 second) second)
»» event based: event based: the model calculates changes in the the model calculates changes in the
system when something ’happens’ (events) system when something ’happens’ (events)
Page 5


Microscopic
Traffic Modeling
Traffic model classification Traffic model classification ( (1 1) )
nn Static Static
– – Models average steady Models average steady- -state traffic situation state traffic situation
nn Dynamic Dynamic
– – Models Models changes over time changes over time of the traffic situation of the traffic situation
7:00 10:00 15:00 18:00
Dynamic
Static
raffic model classification ( Traffic model classification (2 2) )
nn Different levels of detail in Different levels of detail in simulation simulation
models: models:
–– Macroscopic: Macroscopic:
» » Like water flowing through a pipe Like water flowing through a pipe
–– Mesoscopic Mesoscopic
» » Individual vehicles with aggregate behaviour Individual vehicles with aggregate behaviour
–– Microscopic Microscopic
» » Individual vehicles with detailed behaviour Individual vehicles with detailed behaviour
raffic model classification ( Traffic model classification (3 3) )
nn Other dimensions: Other dimensions:
–– Stochastic or Deterministic Stochastic or Deterministic::
»» stochastic stochastic modelling captures variation in e.g. modelling captures variation in e.g.
reaction time, arrival processes, route choice. reaction time, arrival processes, route choice. But But
every simulation run results in different outcome, so every simulation run results in different outcome, so
you need to you need to replicate simulation runs replicate simulation runs
–– Time Time- -stepped or event stepped or event- -based: based:
»» Time stepped Time stepped: the model calculates the changes in : the model calculates the changes in
the system for finite steps (e.g. the system for finite steps (e.g. 1 1 second) second)
»» event based: event based: the model calculates changes in the the model calculates changes in the
system when something ’happens’ (events) system when something ’happens’ (events)
Introduction to micro Introduction to micro- -simulation simulation
nn ““A numerical technique for A numerical technique for
conducting experiments on a digital conducting experiments on a digital
computer, which may computer, which may…… involve involve
mathematical models that describe mathematical models that describe
the behaviour of a transportation the behaviour of a transportation
system over extended periods of time. system over extended periods of time.””