I-95 Corridor Coalition

Transcription

1 I-95 Corridor Coalition I-95 Corridor Coalition Vehicle Probe Project: Validation of INRIX Data Report for New Hampshire (#1) I-89 and I-93 October 2016

2 I-95 CORRIDOR COALITION VEHICLE PROBE PROJECT VALIDATION OF INRIX DATA OCTOBER 2016 Report for New Hampshire (#1) I-89 and I-93 Prepared for: I-95 Corridor Coalition Sponsored by: I-95 Corridor Coalition Prepared by: Masoud Hamedi, Sanaz Aliari, Zhongxiang Wang University of Maryland, College Park Acknowledgements: The research team would like to express its gratitude for the assistance it received from the state highway officials in New Hampshire during the course of this study. Their effort was instrumental during the data collection phase of the project. This report would not have been completed without their help. October 2016 Vendor: INRIX 1

3 Evaluation Results for the State of New Hampshire Executive Summary The data from the Vehicle Probe Project is validated using Bluetooth TM Traffic Monitoring (BTM) technology on a near monthly basis. BTMs sensors were deployed at the beginning and ending points of 12 different segments along the I-89 and I-93 corridors. Average Annual Daily Traffic (AADT) is 33,000 along I-89 and 68,460 along I-93. The speed limit varies between 45 to 65 MPH for both I-89 and I-93. The Bluetooth sensor deployment covers the range from I-93 to Stickney Hill Rd along I-89, and between exits 4 and 5 and also exits 11 and 15 along I-93. Travel time data was collected for both directions, between July 8 and July 22, The dataset collected represents approximately 2,447 hours of observations along 12 directional freeway segments, totaling approximately 33 miles. The total number of effective five-minute travel time samples observed was 29,360. ES Table 1, below summarizes the results of the comparison between the BTM reference data and the INRIX data for freeway segments during the above noted time period. As shown, the average absolute speed error (AASE) were within specification in all speed bins, and the Speed Bias (SEB) were within specification in all speed bins except for the 0-30 MPH speed category. ES Table 1 New Hampshire Evaluation Summary for Freeway Speed Bin Average Absolute Speed (<10mph) Speed Bias (<5mph) Number of 5 Minute Samples Hours of Data Collection Comparison Comparison Comparison Comparison with SEM with SEM with Mean with Mean Band Band 0-30 MPH MPH MPH >60 MPH All Speeds Based upon data collected between July 8 and July 22, 2016 across 33 miles of roadway. Vendor: INRIX 2

4 Data Collection Travel time samples were collected along 12 directional freeway segments with the assistance of New Hampshire Department of Transportation (NHDOT) personnel. Freeway segments studied were located on the I-89 corridor from I-93 to Stickney Hill Rd and on I- 93 corridor between exits 4 and 5 and also exits 11 and 15. Travel time data was collected for both directions along I-89 and I-93 corridors between July 8 and July 22, Segment locations were chosen with a high-likelihood of observing recurrent and non-recurrent congestion during peak and off-peak periods. Figure 1 and 2 present an overview snapshot of the placement of sensors for the collection of data on the I-89 and I-93 corridors in New Hampshire, respectively. Average Annual Daily Traffic (AADT) is 33,000 along I-89 and 68,460 along I-93. The speed limit varies between 45 to 65 MPH for both I-89 and I-93. Blue segments represent freeway segments selected for analysis. Figure 1 Locations of segment selected on I-89 for analysis in New Hampshire Vendor: INRIX 3

5 Figure 2 Locations of segments selected on I-93 for analysis in New Hampshire Vendor: INRIX 4

6 TMC segments selected for validation in New Hampshire Table 1 presents the data collection segments from New Hampshire. As a whole, these segments cover a total length of 33 miles. Data collection segments are comprised of one or more Traffic Message Channel (TMC) base segments, such that the total length of the data collection segment is one mile long or greater for freeways. When appropriate, consecutive TMC segments are combined to form a data collection segment longer than one mile. The results of the validation performed on 12 directional freeway segments are included in this report. Table 1 contains the summary information on each data collection segment including the latitude/longitude coordinates of the locations at which the Bluetooth sensors were deployed along I-89 and I-93 in New Hampshire as well as an active map link to view the data collection segment in detail. Click on the map link to see a detailed map for the respective data collection segment. It should be noted that the configuration of the test segments is often such that the endpoint of one segment coincides with the start point of the next segment, so that one Bluetooth sensor covers both data collection segments. Table 1 also provides data on the precise length of the TMCs comprising the test segment as compared to the measured length between Bluetooth TM Traffic Monitoring (BTM) sensors placed on the roadway. An algorithm was developed and documented in a separate report 1 as part of the initial VPP project and is being used for the validation of all vendors in VPPII. Details of the algorithm used to estimate equivalent path travel times based on INRIX data feeds for individual data collection segments are provided in this separate report. This algorithm finds an equivalent INRIX travel time (and therefore travel speed) corresponding to each sample BTM travel time observation on the test segment of interest. 1 Ali Haghani, Masoud Hamedi, Kaveh Farokhi Sadabadi, Estimation of Travel Times for Multiple TMC Segments, prepared for I-95 Corridor Coalition, February 2010 (link) Vendor: INRIX 5

7 Table 1 Segments selected for validation in New Hampshire SEGMENT DESCRIPTION TMC CODES Deployment (Map Link) Freeway State Starting at Begin Number Begin Lat/Lon Length NH County Ending at End Length End Lat/Lon % Diff Freeways All Lengths in Miles F1 I-89 New Hampshire I P NH Northbound Merrimack Stickney Hill Rd/Exit 3 129P % F2 I-89 New Hampshire Stickney Hill Rd/Exit 3 129N NH Southbound Merrimack I N % F3 I-93 New Hampshire I-393/US-202/US-4/Exit N NH Southbound Merrimack US-3/Manchester St/Exit N % F4 I-93 New Hampshire US-3/Manchester St/Exit N NH Southbound Merrimack NH-3A/Main St/Exit N % F5 I-93 New Hampshire I N NH Southbound Merrimack Hackett Hill Rd/Exit N % F6 I-93 New Hampshire Hackett Hill Rd/Exit N NH Southbound Merrimack Hackett Hill Rd/Exit N % F7 I-93 New Hampshire NH-28/Rockingham Rd/Exit 5 129N NH Southbound Hillsborough NH-102/Nashua Rd/Exit 4 129N % F8 I-93 New Hampshire NH-102/Nashua Rd/Exit 4 129P NH Northbound Rockingham NH-28/Rockingham Rd/Exit 5 129P % F9 I-93 New Hampshire Hackett Hill Rd/Exit P NH Northbound Merrimack I P % F10 I-93 New Hampshire I P NH Northbound Merrimack I P % F11 I-93 New Hampshire I P NH Northbound Merrimack US-3/Manchester St/Exit P % F12 I-93 New Hampshire US-3/Manchester St/Exit P NH Northbound Merrimack I-393/US-202/US-4/Exit P % Vendor: INRIX 6

8 Analysis of Freeway Results Table 2 summarizes the data quality measures obtained as a result of a comparison between Bluetooth and all reported INRIX speeds. Specifications used for comparison include the Average Absolute Speed (AASE) and the Speed Bias (SEB). Average Absolute Speed (AASE) The AASE is defined as the mean absolute value of the difference between the mean speed reported from the VPP and the ground truth mean speed for a specified time period. The AASE is the primary accuracy metric. Based on the contract specifications, the speed data from the VPP shall have a maximum average absolute error of 10 miles per hour (MPH) in each of four speed ranges: 0-30 MPH, MPH, MPH, and > 60 MPH. Speed Bias (SEB) The SEB is defined as the average speed error (not the absolute value) in each speed range. SEB is a measure of whether the speed reported in the VPP consistently under or over estimates speed as compared to ground truth speed. Based on the contract specifications, the VPP data shall have a maximum SEB of +/- 5 MPH in each of speed ranges as defined above. The results are presented as compared against the mean of the ground truth data as well as the 95 th percent confidence interval for the mean, referred to as the Standard of the Mean (SEM). The SEM takes into account any uncertainty in the ground truth speed as measured by BTM equipment due to limited samples and/or data variance. Contract specifications are assessed against the SEM. (See the Vehicle Probe Project: Data Use and Application Guide for additional details on the validation process.) The AASE in the lower two speed s have proven to be the critical specification (and most difficult) to attain. As shown, the average absolute speed error (AASE) were within specification in all speed bins, and the Speed Bias (SEB) were within specification in all speed bins except for the first speed bin (0-30 MPH). Vendor: INRIX 7

9 TABLE 2 Data quality measures for freeway segments in New Hampshire SPEED BIN Data Quality Measures for 1.96 SEM Band Mean SEB AASE 5 mph 10 mph (contract specifications) SEB AASE No. of 5 Minute Samples Hours of Data Collection Table 3 shows the percentage of the time INRIX data falls mph of the SEM and the mean for each speed bin for all freeway data segments in this validation report. SPEED BIN Table 3 Percent observations meeting data quality criteria for freeway segments in New Hampshire Data Quality Measures for 1.96 SEM Band Mean Percentage falling inside the Percentage falling mph of the Percentage equal to the mean Percentage mph of the mean No. of Obs % 49% 0% 36% % 53% 0% 41% % 80% 0% 40% % 93% 0% 72% Tables 4 and 5 present detailed data for individual TMC segments in this validation in a similar format as Tables 2 and 3, respectively. Note that for some segments and in some speed bins the comparison results may not be reliable due to the small number of observations. Vendor: INRIX 8

10 Table 4 Data quality measures for individual freeway validation segments in the state of New Hampshire TMC Standard TMC length Bluetooth distance NH NH NH NH NH NH NH NH NH NH NH SPEED BIN Data Quality Measures for 1.96 SEM Band Mean Speed Bias Average Absolute Speed Speed Bias Average Absolute Speed No. of Obs * * * * * * * * * * * * * *Results in the specified row may not be reliable due to small number of observations Vendor: INRIX 9

11 Table 4 (Cont d) Data quality measures for individual freeway validation segments in the state of New Hampshire TMC Standard TMC length Bluetooth distance NH SPEED BIN Data Quality Measures for 1.96 SEM Band Mean Speed Bias Average Absolute Speed Speed Bias Average Absolute Speed No. of Obs *Results in the specified row may not be reliable due to small number of observations Vendor: INRIX 10

12 Table 5 Observations meeting data quality criteria for individual freeway validation segments in the state of New Hampshire TMC SPEED BIN Data Quality Measures for 1.96 SEM Band Mean Average Absolute Speed Speed Bias Speed Bias No. falling inside the % falling inside the No. falling mph of the % falling mph of the No. equal to the mean % equal to the mean Average Absolute Speed No. mph of the mean % within 5 mph of the mean NH % 6 50% 0 0% 6 50% 12* % % 0 0% % % 48 73% 0 0% 33 50% 66 NH % 23 77% 0 0% 20 67% % 76 76% 0 0% 62 62% % % 0 0% % % 23 58% 0 0% 22 55% 40 NH % % 0 0% % % % 0 0% % % % 1 0% % % 0 0% 0 0% 0 0% 19* NH % 22 55% 0 0% 20 50% % % 0 0% 84 11% % % 1 0% % % 13 48% 0 0% 12 44% 27* NH % 5 38% 0 0% 5 38% 13* % 22 63% 0 0% 16 46% % % 1 0% % % 7 64% 0 0% 7 64% 11* NH % 8 36% 0 0% 5 23% 22* % 32 52% 0 0% 24 39% % % 0 0% % % 13 65% 0 0% 10 50% 20* NH % 22 79% 0 0% 18 64% 28* % 25 45% 0 0% 22 40% % % 0 0% % % 6 50% 0 0% 6 50% 12* NH % 21 75% 0 0% 20 71% 28* % 72 67% 0 0% 56 52% % % 0 0% % % 29 88% 0 0% 27 82% 33 NH % 9 33% 0 0% 4 15% 27* % 5 19% 0 0% 2 8% 26* % % 1 0% % % 33 45% 0 0% 32 43% 74 NH % 4 11% 0 0% 3 9% % 21 72% 0 0% 17 59% 29* % % 0 0% % % 39 24% 0 0% 36 22% 161 NH % 2 4% 0 0% 2 4% % 75 43% 0 0% 45 26% % % 0 0% % 2018 *Results in the specified row may not be reliable due to small number of observations No. of Obs. Vendor: INRIX 11

13 Table 5 (Cont d) Observations meeting data quality criteria for individual freeway validation segments in the state of New Hampshire TMC SPEED BIN Data Quality Measures for 1.96 SEM Band Mean Average Absolute Speed Speed Bias Speed Bias No. falling inside the % falling inside the No. falling mph of the % falling mph of the No. equal to the mean % equal to the mean Average Absolute Speed No. mph of the mean % within 5 mph of the mean % 17 22% 0 0% 11 14% % 47 27% 0 0% 40 23% 174 NH % % 0 0% % % % 3 0% % 1126 *Results in the specified row may not be reliable due to small number of observations No. of Obs. Vendor: INRIX 12