Analysis of a Stochastic Switched Model of Freeway Traffic Incidents
Jin Li, Saurabh Amin

Citation
Jin Li, Saurabh Amin. "Analysis of a Stochastic Switched Model of Freeway Traffic Incidents". IEEE TAC (revise and resubmit), 2016.

Abstract
This article models the interaction between freeway traffic dynamics and capacity-reducing incidents as a stochastic switched system, and analyzes its long-time properties. Incident events on a multi-cell freeway are modeled by a Poisson-like stochastic process. Randomness in the occurrence and clearance of incidents results in traffic dynamics that switch between a set of incident modes (discrete states). The rates of occurrence and clearance depend on the traffic densities (continuous state). The continuous state evolves in each incident mode according to mode-dependent macroscopic flow dynamics. At steady state, the system state resides in its accessible set, which supports an invariant probability measure. Behavior of the accessible set is studied in terms of inputs (on-ramp inflows) and incident parameters (incident intensity). An over-approximation of accessible set and some useful bounds on the performance metrics (throughput and travel time) are also derived using the limiting states of individual incident modes. These results provide following insights about the steady-state system behavior: (i) Expected loss of throughput increases with the incident intensity for fixed incident rate, but this loss is less sensitive to changes in the occurrence rate for fixed intensity; (ii) Operating an incident-prone freeway close to its capacity significantly increases the expected travel time; (iii) The impact of incidents reduces when certain inputs upstream of incident-prone sections are metered.

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Citation formats  
  • HTML
    Jin Li, Saurabh Amin. <a
    href="http://www.cps-forces.org/pubs/146.html"
    >Analysis of a Stochastic Switched Model of Freeway
    Traffic Incidents</a>, <i>IEEE TAC (revise and
    resubmit)</i>,  2016.
  • Plain text
    Jin Li, Saurabh Amin. "Analysis of a Stochastic
    Switched Model of Freeway Traffic Incidents".
    <i>IEEE TAC (revise and resubmit)</i>,  2016.
  • BibTeX
    @article{LiAmin16_AnalysisOfStochasticSwitchedModelOfFreewayTrafficIncidents,
        author = {Jin Li and Saurabh Amin},
        title = {Analysis of a Stochastic Switched Model of Freeway
                  Traffic Incidents},
        journal = {IEEE TAC (revise and resubmit)},
        year = {2016},
        abstract = {This article models the interaction between
                  freeway traffic dynamics and capacity-reducing
                  incidents as a stochastic switched system, and
                  analyzes its long-time properties. Incident events
                  on a multi-cell freeway are modeled by a
                  Poisson-like stochastic process. Randomness in the
                  occurrence and clearance of incidents results in
                  traffic dynamics that switch between a set of
                  incident modes (discrete states). The rates of
                  occurrence and clearance depend on the traffic
                  densities (continuous state). The continuous state
                  evolves in each incident mode according to
                  mode-dependent macroscopic flow dynamics. At
                  steady state, the system state resides in its
                  accessible set, which supports an invariant
                  probability measure. Behavior of the accessible
                  set is studied in terms of inputs (on-ramp
                  inflows) and incident parameters (incident
                  intensity). An over-approximation of accessible
                  set and some useful bounds on the performance
                  metrics (throughput and travel time) are also
                  derived using the limiting states of individual
                  incident modes. These results provide following
                  insights about the steady-state system behavior:
                  (i) Expected loss of throughput increases with the
                  incident intensity for fixed incident rate, but
                  this loss is less sensitive to changes in the
                  occurrence rate for fixed intensity; (ii)
                  Operating an incident-prone freeway close to its
                  capacity significantly increases the expected
                  travel time; (iii) The impact of incidents reduces
                  when certain inputs upstream of incident-prone
                  sections are metered.},
        URL = {http://cps-forces.org/pubs/146.html}
    }
    

Posted by Saurabh Amin on 16 Apr 2016.
Groups: forces
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