Validating Predicted Rural CorridorTravel Times from an AutomatedLicense Plate Recognition System:
Oregon’s Frontier Project
Presented by:Zachary HorowitzPortland State UniversityJuly 12, 2005
Presentation Outline Introduction and Research Objective
Study Corridor
Frontier Time Travel System
Data
Analysis
Results and Conclusions
Frontier Time Travel Project California – Oregon Advanced Transportation
System (COATS)
ITS Technology deployed in rural settings
Pooled Fund Study in eight western states
Research Objective
A field evaluation of a corridor time travelprediction system using license plate recognitionsoftware
Study Area – Camera Locations
3.15 mi22.25 mi
6 Cameras/3 Sites (1 per direction) US 101 north of Lincoln City OR-18 near Otis OR-18 near Grand Ronde
Study Area – OR-18 Details
25 mile rural route between Portland and Oregon coast Primarily 2-lane highway with passing lanes Carries heavy weekend, recreational travel Major truck route to coast Known to be congested during weekends/holidays and summer Average daily traffic (ADT):
East of Grand Ronde: 20,000 West of Grand Ronde: 10,000
No traffic signals Directional interchange at US 101
http://www.epinions.com/park-Parks-All-OR-HB_Van_Duzer_Forest_State_Scenic_Corridor
Frontier Travel Time SystemCameras, license plateReader, software
Communication
Travel time calculationsoftware / processing
ITS technologiessuch as VMS, Tripcheck
Experiment Almanac
Sunday, July 13, 2003 andFriday, July 2, 2004
Higher volume, summer, weekend, holiday
Sample sizes of probe vehicles: 6, 7
Route: (Lincoln City to Valley Junction to L. City) 2
10 minute headways with SOP instructions
Day 1 – Sunday, July 13, 2003
Palm OS with GPS, running ITS-GPS: 4 veh.
Windows laptop PC’s, running CoPilot: 2 veh.
Day 2 – Friday, July 2, 2004
Palm OS with GPS, running ITS-GPS: 5 veh.
Windows laptop PC’s, running CoPilot: 2 veh.
Data Collected
Date, time, speed at 3 sec. intervals, latitude, longitude, distance and time between readings
Trajectories plotted on a time space diagram (x,t)
t
x
Spherical geometry used to calculatedistance between points
ODOT data for study days:
Date, time, site ID, link ID, # of matched plates, average travel time between sites
Data Difficulties
GPS fixes lost – 3 sec re-establishment times
Error distribution:
Interpolated distance =
Distance between readings (25.4 / Total distance measured by GPS unit)
ODOT Frontier Data – Sun. July 13
ODOT Frontier Data – Fri. July 2
Statistical Analysis
α = .05, 95% confidence interval
Errors
Differences between times predicted with the Frontier system and the probe vehicles
Segment 1 Segment 2
Short segments revealed over-prediction by FrontierLong segments revealed under-prediction by Frontier
Results and Conclusions Based on the data, the Frontier Travel Time system
located on Oregon-18 predicts travel times effectively.
Travel times are accurately predicted within 1 minute.
Travel times could be displayed upstream of corridor using VMS located at key junctions.
Additional tests would help to improve data. Data latency and hardware reliability were issues.
Acknowledgements Robert Fynn, ODOT FHWA and the WTI at Montana State University Steve Albert and Patrick Wright, WTI Annette Clothier and Galen McGill, ODOT Tarek Abou El-Seoud “Probe” vehicle drivers Dr. Robert Bertini, PSU Dr. Chris Monsere, PSU Matt Lasky, PSU
www.its.pdx.edu