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Research in the Smart Travel and Traffic Operations Laboratories. Hyungjun Park Department of Civil and Environmental Engineering. ITS Virginia April 30, 2008. Smart Travel Lab (STL) and Traffic Operations Lab (TOL). Facilities developed to support applied ITS research
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Research in the Smart Travel and Traffic Operations Laboratories Hyungjun Park Department of Civil and Environmental Engineering ITS Virginia April 30, 2008
Smart Travel Lab (STL) and Traffic Operations Lab (TOL) • Facilities developed to support applied ITS research • Distinguishing characteristics • Direct integration with VDOT and local traffic control systems • Development of prototype systems • Extensive simulation capabilities • Combined, STL and TOL, provide ability to investigate modern integrated corridor challenges • STL – freeways • TOL – arterials
Selected Research Areas • Signal Control • Travel Time • Integrated Corridor Management • Vehicle Infrastructure Integration
Signal Control • Dynamic Gap Out • Time-of-Day Control
Dynamic Gap Out • Objective • To quantify benefits of dynamic gap-out under VII (or advanced area-wide detection system) • Key Findings to Date • Simulation study shows ~20% total delay reduction on two one-way streets, and ~11% on a four leg intersection for medium to high volume cases
Two One-Way Streets Four Leg Intersection Dynamic Gap-Out (Veh-hrs) Dynamic Gap-Out (Veh-hrs) Traditional Gap-out (Veh-hours) Traditional Gap-out (Veh-hours)
Time-of-Day Control • Objective • To determine optimal TOD break points with explicit transition cost consideration • Key Findings to Date • Optimization approach significantly reduced network delay • Simulation results show that optimized TOD is also robust under varying and increased demand conditions
Initial & Optimized TOD TOD Performance Comparison
Travel Time • Evaluation of travel time data services • Optimal placement of point detectors
Evaluation of Travel Time Data Services • Objective • To allow transportation agencies to make better informed decisions when considering the purchase of a travel time data service • Key Findings to Date • Completed evaluation of Airsage service in the Northern Virginia region
Airsage Evaluation Conclusions • The Airsage system provides link speed/travel time estimates for 83% of the possible 5-min time intervals • Travel time estimates evaluation results • The Airsage system • Is capable of tracking trends • But doesn’t seem to be good enough as a sole source
Optimal Placement of Point Detectors • Objective • To help VDOT make better locate point sensors to use in deriving travel time estimates • Key Findings to Date • Methodology has been developed using GPS travel time runs as “baseline” data • Currently, the STL is developing a web-based tool to allow VDOT regions to fine-tune detector placement.
Location of the Optimal Set of Detectors for I66 WB Study Section (14 detectors)
Integrated Corridor Management • Analysis of HOV/HOT Enforcement Operations
Analysis of HOV/HOT Enforcement Operations • Objective • To explore the impact of HOV/HOT enforcement and to identify preferred methods/technologies • Key Findings to Date • Current enforcement appears to have little impact on HOV violation rate
Large-scale VSP Enforcement on 3/24/08 – 250 summons issued
Vehicle Infrastructure Integration (VII) • Simulation Environment • VII Ramp Metering
Vehicle Infrastructure Integration (VII) Backhaul Communication Service Delivery Node DSRC Public and Private Users Roadside Units DSRC DSRC Traffic Signal Controller
VII Simulation Architecture • Components • Traffic Simulator • VII Interface Module • Applications • Database
VII Ramp Metering • Objective • To investigate how to improve ramp metering using individual vehicular data/control from VII • Key Findings to Date • Encouraging early lane-changes at upstream mainline to open up more spaces for ramp merging has marginal benefits: 2% increase in VMT and 2% reduction in VHT • Setting up ramp signals based on the expected gap availability is being investigated
For More Information Brian L. Smith briansmith@virginia.edu http://cts.virginia.edu