Assessing Segment- and Corridor-Based Travel-Time Reliability on Urban Freeways

Project Details
STATUS

Completed

START DATE

08/15/14

END DATE

09/30/16

RESEARCH CENTERS InTrans, CTRE, MTC
SPONSORS

Iowa Department of Transportation
Midwest Transportation Center
USDOT/OST-R

Researchers
Principal Investigator
Jing Dong-O'Brien

Transportation Engineer, CTRE

Co-Principal Investigator
Neal Hawkins

Director Research Administration, ISU

About the research

Travel time and its reliability are intuitive performance measures for freeway traffic operations. The objective of this project was to quantify segment-based and corridor-based travel time reliability measures on urban freeways. To achieve this objective, a travel-time estimation model and a travel-time reliability prediction framework were developed.

The proposed travel-time estimation model considers spatially correlated traffic conditions. Segment-level and corridor-level travel-time distributions were estimated using travel time estimates and compared with estimates based on probe vehicle data. Corridor-level travel-time reliabilitymeasures were extracted from travel-time distributions. The proposed travel-time estimation model can well capture the temporal pattern of travel time and its distribution.

For the corridor-level travel-time reliability prediction framework, travel time observations are classified based on weather conditions, segment travel-time distributions are estimated, and segment travel-time distributions are synthesized to corridor travel-time distributions. The segment travel-time distribution estimation model was found to capture the pattern of actual travel-time distributions and could adequately represent the short-term corridor-level travel-time distributions. The proposed travel-time reliability prediction framework provides a systematic way to estimate real-time and near-future corridor travel-time reliability by considering weather impact.

A Vissim simulation calibrated to Iowa compared travel-time distribution based on simulated data to that based on probe vehicle data. The simulated travel-time distribution is similar to thetravel-time distribution based on probe data.


Funding Sources:
Iowa Department of Transportation ($100,000.00)
Midwest Transportation Center
USDOT/OST-R ($75,000.00)
Total: $175,000.00

Contract Number: DTRT13-G-UTC37

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