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A Traffic Chaos Reduction Approach for Emergency Scenarios. NetCri’07 The First International Workshop on Research Challenges in Next Generation Networks for First Responders and Critical Infrastructures April 13th, 2007. - PowerPoint PPT Presentation
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A Traffic Chaos Reduction A Traffic Chaos Reduction Approach for Emergency ScenariosApproach for Emergency Scenarios
Syed R. Rizvi†, Stephan Olariu†, Mona E. Rizvi‡, and Michele C. Weigle†
†Department of Computer Science, Old Dominion University, Norfolk, VA
‡ Department of Computer Science, Norfolk State University, Norfolk, VA
NetCri’07
The First International Workshop on Research Challenges in Next Generation Networks for First Responders and Critical Infrastructures
April 13th, 2007
Problems AddressedProblems Addressed
Traffic chaos caused by presence of emergency vehicles– sirens– increased accidents for emergency
personnel
Traffic chaos caused by large-scale evacuations– resource availability– contraflow
Our ApproachOur Approach
Efficient chaos-reducing information dissemination approach– targeted towards first responders and evacuations– using a vehicular ad-hoc network (VANET)
Provide emergency vehicle path-clearing technique
Provide real-time resource availability information
AssumptionsAssumptions
All vehicles act as information servers relaying information for the VANET.
No location servers or access points on the roadside.
Every vehicle has a navigation system, which plans its route and knows its current location.
Building BlocksBuilding Blocks
Resources: emergency service vehicles (ESVs), gas stations, hospitals, shelters, etc.
Reports: information sent by resources
Dissemination: wireless broadcast
Selection strategies: based on spatial relevance
ESV Route Traffic Chaos Reduction ESV Route Traffic Chaos Reduction Approach Approach
The ESV periodically broadcasts a report containing:– unique ID of ESV
– type of ESV
– start and end points
– route code
– tentative average speed of ESV along route
– current ESV location and time
– timestamp of report sent by the ESV
Clearing Time ComputationClearing Time Computation
Each vehicle in the path computes the time to intersection with the ESV based on the average ESV speed, ESV location, and current time
Driver should give way to ESV between 30-60 seconds before intersection time
Report Selection StrategyReport Selection Strategy
The relevance of a resource report is calculated through a relevance function– time report was sent– distance from the ESV– speed of the ESV
Periodically, reports in a vehicle’s database are sorted according to relevance
Most relevant report is used for computing clearing time and is broadcast to neighbors
Connecticut A
ve,
Point P {px,py}
Point R {rx,ry}
Street Code: 13
Street Code: 14
Street Code: 15
Street Code: 12
Street Code: M
Street Code: N
Street Code: O
Street Code: P
Street C
ode: cnt
Start {sx,sy}
End {dx,dy}
{(sx,sy)/cnt, (px,py)/O, (rx,ry)/15, (dx,dy)}
ESV Route CodeESV Route Code
Evacuation Traffic Chaos Evacuation Traffic Chaos Reduction ApproachReduction Approach
Resources (gas stations, shelters, hospitals) periodically broadcast reports– type of resource– availability of resource– location– timestamp of report
Reports updated as availability changes
Information filtered for relevance according to vehicle’s location
ESV Simulation ModelESV Simulation Model
Written in– use of multiple threads for traffic generation,
automobiles and ESVs.
Mobility model– nodes move in piecewise linear fashion, following
city streets.
Simulation ParametersSimulation Parameters
Simulation ResultsSimulation Results
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
5 25 45 65Vehicular Density (vehicles/sq. km.)
Data success rate– ratio of number of
vehicles on ESV route that receive the message in time to clear the path to the total number of vehicles on the ESV route
As expected, increasing the density of vehicles, improves the success rate
Vehicular Density (vehicles/km2)D
ata
Suc
cess
Rat
e
ConclusionConclusion
Traffic Chaos Reduction Approach for Emergency Scenarios– emergency service vehicle path-clearing– evacuation resource availability
Future Work– improve simulation/mobility model– investigate bandwidth usage– investigate security issues
Department of Computer Science
Old Dominion University
Norfolk, Virginia
VANET Research Group
http://www.cs.odu.edu/~vanet
Department of Computer Science
Norfolk State University
Norfolk, Virginia