Validating Predicted Rural Corridor Travel Times from an Automated License Plate Recognition System: Oregon’s Frontier Project Presented by: Zachary Horowitz Portland State University July 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 travel prediction system using license plate recognition software

Study Area – Camera Locations 3.15 mi 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

Frontier Travel Time System Cameras, license plate Reader, software Communication Travel time calculation software / processing ITS technologies such as VMS, Tripcheck

Experiment Almanac Sunday, July 13, 2003 and Friday, 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 calculate distance 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 1Segment 2 Short segments revealed over-prediction by Frontier Long 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