1. COMMUNICATING PERFORMANCE TO PUBLIC @ VDOT Sanhita Lahiri, P.E., PTOE sanhita.lahiri@vdot.virginia.gov 1

2. Holiday Travel Trend  Before Probe Data  Using Probe Data −Methodology −Challenges & Opportunities Real Time Traveler Information Questions 2 OUTLINE

3. 3 Used Data from ~300 Continuous Count Stations -Between interchanges -Coverage limitations -Large temporal aggregations -10 pages to show all Interstates Before Probe Data H OLIDAY T RAVEL T REND

4. 4 3 years of Probe Data 30 minute intervals One page to view all data Using Probe Data H OLIDAY T RAVEL T REND

5.  Prepare Data for Averaging – Standard deviations (STDV) of speeds over latest 3 years are calculated and a threshold STDV is chosen based on the full data set 5 Data Analysis Methodology H OLIDAY T RAVEL T REND

6.  Prepare Data for Averaging – The threshold STDV is compared to STDV of each data set and SD that exceeds the threshold are identified as outliers. Data could be Outlier for several reasons including, weather conditions, Incidents, Work Zone, Special Events Process of elimination is used for the outlier data 6 Data Analysis Methodology H OLIDAY T RAVEL T REND

7. 7 Interstates Speed LimitThresholdCongestion Level Urban (60 mph or 55 mph) 55 mph or aboveLittle to No Congestion between 45 and 54 mphModerate Congestion less than 45 mphHeavy Congestion Rural (65 mph or 70 mph) 63 mph or aboveLittle to No Congestion between 45 and 62 mphModerate Congestion less than 45 mphHeavy Congestion Limited Access Arterials Speed >= 85% of FFSLittle to No Congestion 85% of FFS > Speed >= 60% of FFSModerate Congestion 60% of FFS > SpeedHeavy Congestion Data Analysis Methodology  Determine Congestion Threshold – Based on experience, speeds (Posted Limits for Interstates and Reference for Arterials), rural or urban area, roadway gradient, speed thresholds were assigned to different levels of congestion.

8.  Elimination of Outlier Data – Remaining outlier data was ready to be averaged if o All three individual yearly speeds had same Congestion Level o Only one of three possible yearly pairs had STDV below threshold. The outlier speed was eliminated and speeds from the other two years were used. o The outlier speed was matched with only one incident. The speed from incident year was eliminated.  Assign Congestion Level based on pre-determined Speed Threshold 8 Data Analysis Methodology H OLIDAY T RAVEL T REND

9. 9 Data Analysis Methodology H OLIDAY T RAVEL T REND Congestion Level Little to No Congestion Moderate Congestion Heavy Congestion Outliers Outlier Smoothing – Remaining outliers were eliminated based on an iterative process based on values from their neighbors.

10. 10 Outlier Statistics H OLIDAY T RAVEL T REND Percent outliers at the end of each data processing step Holiday (using data from Previous 3 yrs) STDV Threshold STDV > Thresh old Diff. Cgst. Levels Elim. Outlier Speed Event(incdt, weather) Mapping Outlier Elim Alg. T’giving, 2012 2012 5 mph 12.1% 10.0% 2.9% 2.8% 0% Mem Day 2013 3.5 mph 10.5% 7.2% 2.3% 2.2% 0% T’giving 2013 4 mph 11.7% 8.6% 2.6% 2.5% 0% Mem Day 2014 4 mph (mainlines) 7 mph (ramps) 9.3% 7.2% 2.5% 2.4% 0% Labor Day 2014 4 mph (mainlines) 7 mph (ramps) 9.3% 6.5% 1.9% 1.8% 0% T’giving 2014 4 mph (mainlines) 7 mph (ramps) 8.7% 5.1% 1.2% 1.1% 0%

11. Local Feedback - Manual Adjustments based on comments and special conditions  RHOV lanes  I-495 Express Lane Construction  I-564 connecting I-64 to the Norfolk Naval Base  I-581 in Roanoke  I-264 Downtown Tunnel  I-77 (Mountainous area)  I-81 (Near Roanoke, Truck Climbing Lns, Bridge Rehabilitation Projects)  Downtown Tunnel in Hampton Roads with Flashing Variable Speed Limits  George Washington Pkwy 11 H OLIDAY T RAVEL T REND Fine Tune Projections

12. 12 Holiday Travel Trends http://vdot2014thanksgiving.iteris.com

13. H OLIDAY T RAVEL T REND 13 Outreach: Press Release Marketing Spots 511 Banner and link Media Interviews Links to/from other states Communications

14. 14 H OLIDAY T RAVEL T REND Challenges and Opportunities  Data Analysis Challenges –  Inadequate Ramp Data  Adjusting Map based on Field Validation  Influence of truck speed on TMC speed on mountains  INRIX data quality, availability and coverage  Understanding Drivers Expectations amidst various travel information available  Visualization Challenges –  Website coding : time-awareness, new interstate shield layer, KML selection by zoom level, custom code for map coloring  Shapefiles for each level of zoom created from basic, undistorted shapefile  Design of Mobile friendly GUI function  Cross mobile devices compatibility – compatibility across various screen resolutions

15. 15 Travel Time on DMS  VDOT began posting real time travel time messages on I-66 in August 2011 as a pilot  Currently VDOT provides travel time on major interstate commuting routes INRIX probe data was used to produce the travel time R EAL T IME

16. 16 511 Website  VDOT began posting real time travel time messages on I-66 in August 2011 as a pilot  Currently VDOT provides travel time on major interstate commuting routes INRIX probe data was used to produce the travel time R EAL T IME

17. 17 Mobile Sharing R EAL T IME

18. Acknowledgements: Mena Lockwood, P.E. Virginia Department of Transportation Simona Babiceanu University of Virginia ITERIS Team 18

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