Validating Predicted Rural Corridor Travel Times from an Automated License Plate Recognition System:...

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