estimation of freeway traffic congestion using probe …€¦ · o van aerde model •full year...

DATE 6/27/2017

ESTIMATION OF FREEWAY TRAFFIC CONGESTION USING PROBE VEHICLE DATA -A CASE STUDY IN SANTA CLARA COUNTY

Anusha Musunuru, Aaron Elias, Mike Aronson

2018 ITE Joint Western & Texas District Meeting

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Background

• Freeway Level of Service (LOS)• Congestion Management Program (CMP)• CMP network• Trends in travel speeds• Congested segments,.......

Background

• Future transportation needs• Alleviate congestion• Informed decisions

Background

• Santa Clara County • 155 miles of freeway• AM and PM peak periods

Source: https://www.worldatlas.com/na/us/ca/c-santa-clara-county-california.html

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Data Sources

• Performance Measureso LOSo Duration of Congestion

• Data Sourceso Aerial Photographyo Floating car runs

Data Sources

• Data Sourceso Floating car runs (HOV)o INRIX Data

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Methodology

Density-Speed Relationship

Methodology

• Mixed Flow Laneso Traffic message channels (TMC)o Merge and diverge points of Rampso Travel speed and travel time for each TMC

Methodology

• HOV Laneso INRIX data cannot separate HOV lane performance datao Floating vehicle surveyso Two mid-week days

o 6:15 am – 9:45 amo 3:15 pm – 6:45 pm

Data Processing

• Mixed Flow Laneso Filter raw datao Calculate 20th Percentile Speed

o ~80th Percentile Travel Time

o Speed contour mapso LOS – based on travel speedso Duration of congestion

Mixed Flow Lanes

• Filter raw datao Data ‘Quality Score’o Score of 30/20/10o Missing datao Midweek days – September & October

• Calculate 20th Percentile Speedo Speed that 20 percent of days – do not exceedo Avoid days with crashes, work zones, and special eventso Worst case in “typical” dayo Recurrent congestion

Mixed Flow Lanes

• Speed contour maps

Mixed Flow Lanes

• LOS calculationo Minimum travel speedo AM and PM peak periods

• Duration of congestiono Speed contour mapso Each TMC segment

Data Processing

• HOV Laneso Same TMC segmentationo No crash, construction/work zone, evento Travel speeds averagedo LOSo No duration of congestion

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Case Study Results

• Freeway Speed, LOS, Estimated Density, Estimated Flow

Case Study Results

• Freeway Miles LOS

Mixed Flow Lanes HOV Lanes

Case Study Results

• US 101 Congestion Duration (as a Percent of Directional Miles)

Case Study Results

• Duration of Congestion

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Next Steps

• Results Comparisono LOS, Speed, Density Comparisono Van Aerde Model

• Full year datao Speed datao TMC level analysis

• Reliability Metricso Travel time indexo Planning time index

Presentation Overview

• Background• Data Sources• Methodology• Case Study Results• Next Steps• Questions?

Questions??