Attachment 5 Example NPMRDS Data Quality Report.pdf

Center for Advanced Transportation Technology Laboratory (CATT Lab)

National Performance Management Research Data Set (NPMRDS) Data Quality Report October 2021

National Performance Management Research Data Set (NPMRDS) | Quarterly Validation Report

Acknowledgments:

The research team would like to express its gratitude to Tennessee DOT for their assistance in collecting the re-identification data used to evaluate the NPMRDS probe data in this report.

Executive Summary Wireless re-identification traffic monitoring (WRTM) sensors are used to characterize travel time / speed conditions on selected road segments and serve as the basis for evaluating NPMRDS probe data accuracy.

Specifications used to quantify NPMRDS data quality include the Average Absolute Speed Error (AASE) and the

Speed Error Bias (SEB).

• WRTM sensors were deployed to collect travel time data along SR-1, an arterial corridor near Nashville, TN

• Travel time data was collected between March 22-April 2, 2021.

• The dataset used for validation represents just over 3600 total hours of observations (summing over 34 arterial segments) across approximately 57 miles of arterial roadway.

• There were 43,327 five-minute travel time samples with valid WRTM data, of which 16,360 had corresponding

NPMRDS records suitable for comparison.

• This report compares NPMRDS reported probe speeds to the ground truth speeds (both mean and confidence band estimates) during each five-minute period.

ES Table 1 summarizes the results of the comparison between the WRTM reference data and the NPMRDS data for all segments. Data quality measures meet the requirements in all speed categories for both SEB and AASE indicators.

ES Table 1 – NPMRDS arterial Evaluation Summary for Tennessee

Speed Bin

Average Absolute Speed Error

(<10mph)

Speed Error Bias

(<5mph) Number of 5

Minute Samples Comparison with SEM Band

Comparison with Mean

Comparison with SEM Band

Comparison with Mean

0-15 MPH 1.12 2.26 0.68 1.09 224

15-25 MPH 2.08 4.57 1.17 2.16 2172

25-35 MPH 1.8 4.9 -0.02 0 5520

>35 MPH 2.42 5.8 -1.06 -1.78 8444

All Speeds 2.15 5.28 -0.39 -0.61 16360

Based on data collected from March/April 2021 across 57 miles of arterial.

Methodology

Corridor Description and Data Collection Travel time samples were collected along a signalized arterial corridor, SR-1, between downtown Nashville and

Murfreesboro, TN from March 22 to April 02, 2021. This corridor, which has an average signal density of about 2 traffic signals per mile, experiences regular recurrent congestion and has an average AADT of 30.8k vehicles (bi-directional). Figure 1 presents an overview of the WRTM sensor placement along the validation segments.

TMC segments selected for validation in Tennessee Table 1 presents the data collection segments from Tennessee, which encompass approximately 57 arterial miles, and are comprised of one or more Traffic Message Channel (TMC) base segments. The target area includes 34 directional validation segments, of which 32 had NPMRDS data suitable for evaluation. The two validation segments that were not used for evaluation had data missing on one of the TMCs, an issue that appears to be related to overlapping/duplicate TMC definitions.

Table 1 contains the summary information for each data collection segment, including the latitude/longitude coordinates of the locations at which the WRTM sensors were deployed along SR-1, as well as other relevant road geometry characteristics.

Figure 1- WRTM sensor locations.

Calculating equivalent NPMRDS speeds on validation segments

Because TMC segments do not typically align perfectly with validation road segment definitions, NPMRDS TMC-based speeds must first be transformed into equivalent validation segment-based speeds for each five-minute period. The algorithm used for this purpose is documented in separate report1, and has been used extensively in

Eastern Transportation Coalition validation efforts.

Data Quality Measures The following sections summarize the data quality measures based on comparison between WRTM and reported

NPMRDS speeds for all vehicles2. Specifications used for comparison include the Average Absolute Speed Error

(AASE) and the Speed Error Bias (SEB).

Average Absolute Speed Error (AASE)

AASE is defined as the mean absolute value of the difference between the mean speed reported from the

NPMRDS and the ground truth mean speed for a specified time interval. The AASE is the primary accuracy metric. Based on the contract specifications, the speed data from the NPMRDS shall have a maximum average absolute error of 10 miles per hour (MPH) in each speed range: 0-15, 15-25, 25-35, and >35 MPH.

Speed Error Bias (SEB)

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 NPMRDS consistently under or over-estimates speed as compared to ground truth speed. The NPMRDS data is required to have a maximum SEB of +/- 5 MPH in each speed bin.

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) 2 The ground-truth data collected for this report as well as detailed daily comparison graphs for all segments are available for download upon request. Please email zvanderl@umd.edu for such inquiries.

http://www.i95coalition.org/wp-content/uploads/2015/02/I-95-CC-Estimation-of-Travel-Times-for-Multiple-TMC-Segments-FINAL2.pdf mailto:zvanderl@umd.edu

Table 1 - Segments selected for validation in Tennessee

Segment (Map

Link)

DESCRIPTION Deployment

Highway Starting at Lane (Min) Signals

AADT

Access Points Begin Lat/Lon Length

(mile) Direction Ending at Lane (Max) Signal/mile Speed Limit End Lat/Lon

Arterial

A1

SR-1 Fesslers Ln 2 9 25524

28 36.14282 -86.74435 2.20

TN2021-01 Southbound E Thompson Ln 2 4.10 45 36.12667 -86.71115

A2

SR-1 E Thompson Ln 2 7 30085

20 36.12667 -86.71115 2.58

TN2021-03 Southbound Donelson Pike 3 2.71 45 36.10623 -86.67304

A3

SR-1 Donelson Pike 2 4 42349

11 36.10623 -86.67304 1.38

TN2021-04 Southbound Franklin Limestone Rd 3 2.90 45 36.09442 -86.65334

A4

SR-1 Franklin Limestone Rd 2 9 36536

18 36.09442 -86.65334 1.88

TN2021-05 Southbound Bell Rd 3 4.79 45 36.07162 -86.63588

A5

SR-1 Bell Rd 2 3 29816

9 36.07162 -86.63588 1.54

TN2021-06 Southbound Mt View Rd 2 1.95 45 36.05433 -86.61869

A6

SR-1 Mt View Rd 2 2 29844

10 36.05433 -86.61869 1.04

TN2021-07 Southbound Hobson Pike 2 1.92 45 36.04286 -86.60653

A7

SR-1 Hobson Pike 2 3 31642

10 36.04286 -86.60653 1.71

TN2021-08 Southbound Waldron Rd 2 1.75 45 36.02436 -86.58615

A8 SR-1 Waldron Rd 2 3

28743 17 36.02436 -86.58615

1.23

TN2021-09 Southbound Floyd Mayfield Dr 2 2.44 45 36.01749 -86.56629

A9

SR-1 Floyd Mayfield Dr 2 5 26613

14 36.01749 -86.56629 2.43

TN2021-10 Southbound Sam Ridley Pkwy (ramps) 2 2.06 45 35.99792 -86.53248 https://www.google.com/maps/dir/36.14282%09-86.74435/36.12667%09-86.71115/@36.1347572,-86.7366266,15z/data=!3m1!4b1!4m10!4m9!1m3!2m2!1d-86.74435!2d36.14282!1m3!2m2!1d-86.71115!2d36.12667!3e0 https://www.google.com/maps/dir/36.12667%09-86.71115/36.10623%09-86.67304/@36.116435,-86.7008498,3735m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.71115!2d36.12667!1m3!2m2!1d-86.67304!2d36.10623!3e0 https://www.google.com/maps/dir/36.10623%09-86.67304/36.09442%09-86.65334/@36.1003159,-86.6675765,1868m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.67304!2d36.10623!1m3!2m2!1d-86.65334!2d36.09442!3e0 https://www.google.com/maps/dir/36.09442%09-86.65334/36.07162%09-86.63588/@36.0830357,-86.6533682,3737m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.65334!2d36.09442!1m3!2m2!1d-86.63588!2d36.07162!3e0 https://www.google.com/maps/dir/36.07162%09-86.63588/36.05433%09-86.61869/@36.0630299,-86.6360276,3738m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.63588!2d36.07162!1m3!2m2!1d-86.61869!2d36.05433!3e0 https://www.google.com/maps/dir/36.05433%09-86.61869/36.04286%09-86.60653/@36.0486057,-86.6169199,1811m/data=!3m1!1e3!4m10!4m9!1m3!2m2!1d-86.61869!2d36.05433!1m3!2m2!1d-86.60653!2d36.04286!3e0 https://www.google.com/maps/dir/36.04286%09-86.60653/36.02436%09-86.58615/@36.0336125,-86.6050964,3624m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.60653!2d36.04286!1m3!2m2!1d-86.58615!2d36.02436!3e0 https://www.google.com/maps/dir/36.02436%09-86.58615/36.01749%09-86.56629/@36.0199877,-86.5805554,1870m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.58615!2d36.02436!1m3!2m2!1d-86.56629!2d36.01749!3e0 https://www.google.com/maps/dir/36.01749%09-86.56629/35.99792%09-86.53248/@36.007705,-86.5668886,7250m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.56629!2d36.01749!1m3!2m2!1d-86.53248!2d35.99792!3e0

Link)

DESCRIPTION Deployment

Highway Starting at Lane (Min) Signals

AADT

Access Points Begin Lat/Lon Length

(mile) Direction Ending at Lane (Max) Signal/mile Speed Limit End Lat/Lon

Arterial

A10 SR-1 Sam Ridley Pkwy (ramps) 2 3

24190 9 35.99792 -86.53248

1.71

TN2021-11 Southbound Mayfield Dr 2 1.76 45 35.97777 -86.51485

A11 SR-1 Mayfield Dr 2 6

20929 15 35.97777 -86.51485

1.42

TN2021-12 Southbound Lee Victory Pkwy (ramps) 2 4.23 45 35.96106 -86.50016

A12

SR-1 Lee Victory Pkwy (ramps) 2 0 29216

6 35.96106 -86.50016 1.19

TN2021-13 Southbound Sam Griffin Rd 2 0.00 45 35.94698 -86.48795

A13

SR-1 Sam Griffin Rd 2 1 31980

11 35.94698 -86.48795 1.90

TN2021-14 Southbound Florence Rd 2 0.53 55 35.92461 -86.46827

A14

SR-1 Florence Rd 2 1 32674

9 35.92461 -86.46827 1.42

TN2021-15 Southbound #N/A 2 0.70 55 35.90791 -86.45334

A15

SR-1 #N/A 2 0

44279

11 35.89816 -86.44508 1.88

TN2021-16 Southbound N Thompson Ln 2 0.00 55 35.87651 -86.42468

A16

SR-1 N Thompson Ln 2 2 27801

20 35.87651 -86.42468 1.88

TN2021-17 Southbound Medical Center Pkwy 2 1.06 45 35.85566 -86.40341

A17 SR-1 Medical Center Pkwy 2 3

33589 16 35.85566 -86.40341

1.13

TN2021-18 Southbound Shelbyville Hwy 2 2.66 45 35.84229 -86.39202

A18

SR-1 Shelbyville Hwy 2 3 33589 16 35.84229 -86.39202 1.13 https://www.google.com/maps/dir/35.99792%09-86.53248/35.97777%09-86.51485/@35.9878272,-86.532414,3626m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.53248!2d35.99792!1m3!2m2!1d-86.51485!2d35.97777!3e0 https://www.google.com/maps/dir/35.97777%09-86.51485/35.96106%09-86.50016/@35.969354,-86.5161872,3742m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.51485!2d35.97777!1m3!2m2!1d-86.50016!2d35.96106!3e0 https://www.google.com/maps/dir/35.96106%09-86.50016/35.94698%09-86.48795/@35.9540235,-86.5028098,3627m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.50016!2d35.96106!1m3!2m2!1d-86.48795!2d35.94698!3e0 https://www.google.com/maps/dir/35.94698%09-86.48795/35.92461%09-86.46827/@35.9357974,-86.4868646,3628m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.48795!2d35.94698!1m3!2m2!1d-86.46827!2d35.92461!3e0 https://www.google.com/maps/dir/35.92461%09-86.46827/35.90791%09-86.45334/@35.9162598,-86.4695566,3629m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.46827!2d35.92461!1m3!2m2!1d-86.45334!2d35.90791!3e0 https://www.google.com/maps/dir/35.89816%09-86.44508/35.87651%09-86.42468/@35.8873392,-86.4436281,3630m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.44508!2d35.89816!1m3!2m2!1d-86.42468!2d35.87651!3e0 https://www.google.com/maps/dir/35.87651%09-86.42468/35.85566%09-86.40341/@35.8660896,-86.4227998,3631m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.42468!2d35.87651!1m3!2m2!1d-86.40341!2d35.85566!3e0 https://www.google.com/maps/dir/35.85566%09-86.40341/35.84229%09-86.39202/@35.8489698,-86.4064707,3632m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.40341!2d35.85566!1m3!2m2!1d-86.39202!2d35.84229!3e0 https://www.google.com/maps/dir/35.84229%09-86.39202/35.85566%09-86.40341/@35.8489698,-86.4064707,3632m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.39202!2d35.84229!1m3!2m2!1d-86.40341!2d35.85566!3e0

DESCRIPTION Deployment

Highway Starting at Lane (Min) Signals

AADT

Access Points Begin Lat/Lon Length

(mile) Direction Ending at Lane (Max) Signal/mile Speed Limit End Lat/Lon

Arterial

TN2021-19 Northbound Medical Center Pkwy 2 2.66 45 35.85566 -86.40341

A19

SR-1 Medical Center Pkwy 2 2 27800

22 35.85566 -86.40341 1.89

TN2021-20 Northbound N Thompson Ln 2 1.06 45 35.87664 -86.42452

A20 SR-1 N Thompson Ln 2 1

44340 12 35.87664 -86.42452

1.88

TN2021-21 Northbound #N/A 2 0.53 55 35.89829 -86.44497

A21

SR-1 #N/A 2 0

31980 9 35.90801 -86.45321

1.42

TN2021-22 Northbound Florence Rd 2 0.0 55 35.92469 -86.46812

A22

SR-1 Florence Rd 2 1 31980

14 35.92469 -86.46812 1.90

TN2021-23 Northbound Sam Griffin Rd 2 0.53 55 35.94707 -86.48779

A23

SR-1 Sam Griffin Rd 2 1 29447

8 35.94707 -86.48779 1.19

TN2021-24 Northbound Lee Victory Pkwy (ramps) 2 0.84 45 35.96117 -86.50003

A24

SR-1 Lee Victory Pkwy (ramps) 2 6 20772

18 35.96117 -86.50003 1.42

TN2021-25 Northbound Mayfield Dr 2 4.24 45 35.97777 -86.51485

A25 SR-1 Mayfield Dr 2 3

24173 9 35.97777 -86.51485

1.71

TN2021-26 Northbound Sam Ridley Pkwy (ramps) 2 1.76 45 35.99802 -86.53232

A26

SR-1 Sam Ridley Pkwy (ramps) 2 5 26588

13 35.99802 -86.53232 2.44

TN2021-27 Northbound Floyd Mayfield Dr 2 2.05 45 36.01765 -86.56625 https://www.google.com/maps/dir/35.85566%09-86.40341/35.87664%09-86.42452/@35.8661063,-86.4328376,7263m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.40341!2d35.85566!1m3!2m2!1d-86.42452!2d35.87664!3e0 https://www.google.com/maps/dir/35.87664%09-86.42452/35.89829%09-86.44497/@35.8874625,-86.4434998,3630m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.42452!2d35.87664!1m3!2m2!1d-86.44497!2d35.89829!3e0 https://www.google.com/maps/dir/35.90801%09-86.45321/35.92469%09-86.46812/@35.916351,-86.4694173,3629m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.45321!2d35.90801!1m3!2m2!1d-86.46812!2d35.92469!3e0 https://www.google.com/maps/dir/35.92469%09-86.46812/35.94707%09-86.48779/@35.9358692,-86.4867502,3744m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.46812!2d35.92469!1m3!2m2!1d-86.48779!2d35.94707!3e0 https://www.google.com/maps/dir/35.94707%09-86.48779/35.96117%09-86.50003/@35.9541197,-86.502666,3627m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.48779!2d35.94707!1m3!2m2!1d-86.50003!2d35.96117!3e0 https://www.google.com/maps/dir/35.96117%09-86.50003/35.97777%09-86.51485/@35.9695019,-86.5162256,3742m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.50003!2d35.96117!1m3!2m2!1d-86.51485!2d35.97777!3e0 https://www.google.com/maps/dir/35.97777%09-86.51485/35.99802%09-86.53232/@35.9879132,-86.532386,3742m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.51485!2d35.97777!1m3!2m2!1d-86.53232!2d35.99802!3e0 https://www.google.com/maps/dir/35.99802%09-86.53232/36.01765%09-86.56625/@36.0078318,-86.5667946,7250m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.53232!2d35.99802!1m3!2m2!1d-86.56625!2d36.01765!3e0

DESCRIPTION Deployment

Highway Starting at Lane (Min) Signals

AADT

Access Points Begin Lat/Lon Length

(mile) Direction Ending at Lane (Max) Signal/mile Speed Limit End Lat/Lon

Arterial

A27 SR-1 Floyd Mayfield Dr 2 3

28799 16 36.01765 -86.56625

1.22

TN2021-28 Northbound Waldron Rd 2 2.46 45 36.02444 -86.58601

A28 SR-1 Waldron Rd 2 3

31642 9 36.02472 -86.58632

1.69

TN2021-29 Northbound Hobson Pike 2 1.78 45 36.04286 -86.60653

A29

SR-1 Hobson Pike 2 2 29844

7 36.04286 -86.60653 1.04

TN2021-30 Northbound Mt View Rd 2 1.92 45 36.05433 -86.61869

A30

SR-1 Mt View Rd 2 3 29816

9 36.05433 -86.61869 1.54

TN2021-31 Northbound Bell Rd 2 1.95 45 36.07162 -86.63588

A31

SR-1 Bell Rd 2 9 36536

18 36.07162 -86.63588 1.88

TN2021-32 Northbound Franklin Limestone Rd 3 4.79 45 36.09442 -86.65334

A32

SR-1 Franklin Limestone Rd 2 4 42349

8 36.09442 -86.65334 1.38

TN2021-33 Northbound Donelson Pike 3 2.90 45 36.10623 -86.67304

A33

SR-1 Donelson Pike 2 7 30091

19 36.10623 -86.67304 2.58

TN2021-34 Northbound E Thompson Ln 3 2.72 45 36.12673 -86.71101

A34

SR-1 E Thompson Ln 2 10 25524

26 36.12673 -86.71101 2.20

TN2021-35 Northbound Spence Ln 2 4.54 45 36.14282 -86.74435 https://www.google.com/maps/dir/36.01765%09-86.56625/36.02444%09-86.58601/@36.0200586,-86.5805306,1870m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.56625!2d36.01765!1m3!2m2!1d-86.58601!2d36.02444!3e0 https://www.google.com/maps/dir/36.02436%09-86.58615/36.04286%09-86.60653/@36.0328913,-86.61292,7247m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.58615!2d36.02436!1m3!2m2!1d-86.60653!2d36.04286!3e0 https://www.google.com/maps/dir/36.04286%09-86.60653/36.05433%09-86.61869/@36.0485947,-86.6213783,3623m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.60653!2d36.04286!1m3!2m2!1d-86.61869!2d36.05433!3e0 https://www.google.com/maps/dir/36.05433%09-86.61869/36.07162%09-86.63588/@36.0630299,-86.6360276,3738m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.61869!2d36.05433!1m3!2m2!1d-86.63588!2d36.07162!3e0 https://www.google.com/maps/dir/36.07162%09-86.63588/36.09442%09-86.65334/@36.0830197,-86.6533682,3621m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.63588!2d36.07162!1m3!2m2!1d-86.65334!2d36.09442!3e0 https://www.google.com/maps/dir/36.09442%09-86.65334/36.10623%09-86.67304/@36.1003411,-86.6719448,3620m/data=!3m2!1e3!4b1!4m10!4m9!1m3!2m2!1d-86.65334!2d36.09442!1m3!2m2!1d-86.67304!2d36.10623!3e0 https://www.google.com/maps/dir/36.10623%09-86.67304/36.1267462,-86.7110172/@36.1165827,-86.7095197,7239m/data=!3m2!1e3!4b1!4m7!4m6!1m3!2m2!1d-86.67304!2d36.10623!1m0!3e0 https://www.google.com/maps/dir/36.12667%09-86.71115/36.14282%09-86.74435/@36.1357068,-86.7451953,14z/data=!3m1!4b1!4m10!4m9!1m3!2m2!1d-86.71115!2d36.12667!1m3!2m2!1d-86.74435!2d36.14282!3e0

The results are presented as compared against the mean of the ground truth data as well as the 95th percent confidence interval for the mean, referred to as the Standard Error of the Mean (SEM) band. The SEM band accounts for uncertainty in the ground truth speed as measured by WRTM equipment due to limited samples and/or data variance. The error measures in the lower two speed bins have proven to be the critical specification

(and most difficult to attain).

Overall Quality Measures Table 2 shows the results of the comparison between the WRTM and NPMRDS data for all segments. Both the average absolute speed error (AASE) and speed error bias (SEB) were within the specifications in all speed bins.

Table 2 - NPMRDS Data quality measures for arterial segments in Tennessee

Speed Bin

Average Absolute Speed Error

(<10mph)

Speed Error Bias

(<5mph) Number of 5

Minute Samples Comparison with SEM Band

Comparison with Mean

Comparison with SEM Band

Comparison with Mean

0-15 MPH 1.12 2.26 0.68 1.09 224

15-25 MPH 2.08 4.57 1.17 2.16 2172

25-35 MPH 1.8 4.9 -0.02 0 5520

>35 MPH 2.42 5.8 -1.06 -1.78 8444

All Speeds 2.15 5.28 -0.39 -0.61 16360

Based on data collected from March/April 2021 across 57 miles of arterial.

Quality Measures by Segment Table 3 presents detailed data for individual test segments. Note that for some segments and in some speed bins there may not be enough five-minute samples to draw reliable conclusions from comparisons between NPMRDS and ground truth WRTM speeds.

Table 3 - NPMRDS data quality measures for individual arterial validation segments in Tennessee

Path

SPEED

BIN

Data Quality Measures for

No. of Obs.

Avg. Absolute Speed Error Speed Error Bias

1.96 SEM Band Mean 1.96 SEM Band Mean

TN2021-01

0-15 3.65 5.52 2.65 3.78 9

15-25 1.46 4.54 0.85 1.8 60

25-35 3 6.29 0.2 -2.05 21

35+ 2.73 5.66 -2.73 -5.66 1

TN2021-03

0-15 0.83 1.73 0.79 1.15 18

15-25 1.81 4.05 -0.29 -0.26 20

25-35 1.39 4.79 -0.05 0.01 78

35+ 2.6 5.79 -1.87 -3.93 36

TN2021-04

0-15 0.48 0.98 -0.42 -0.72 60

15-25 1.43 2.78 -1.43 -2.47 45

25-35 1.94 4.74 -1.26 -2.17 120

35+ 3.58 7.24 -3.17 -5.66 202

TN2021-05

0-15 0 0.27 0 0.27 3

15-25 0.84 2.43 -0.48 -1.21 16

25-35 2.01 4.08 2.01 2 5

35+ - - - - -

NJ15-0006

0-15 0.92 1.98 0.18 0.47 18

15-25 1.12 2.77 0.5 0.98 241

25-35 1.4 4.15 -0.13 -0.58 496

35+ 2.66 6.82 -1.91 -4.6 77

TN2021-07

0-15 0 0.23 0 0.23 1

15-25 1.25 3.66 0.59 0.95 106

25-35 1.53 5.19 -0.73 -1.37 278

35+ 2.87 7.27 -2.64 -5.82 328

TN2021-08

0-15 0.57 1.54 -0.03 -0.45 14

15-25 1.31 3.14 -0.16 -0.53 81

25-35 1.57 4.57 -0.47 -0.75 268

35+ 2.42 6.16 -1.56 -3.03 144

TN2021-09

0-15 1.9 3.98 1.9 3.98 2

15-25 2.87 5.69 2.11 3.5 161

25-35 2.31 5.4 0.48 1.18 567

35+ 3.29 6.31 -2.62 -3.82 42

TN2021-10

0-15 - - - - -

15-25 - - - - -

25-35 2.39 5.08 2.39 5.08 5

35+ 2.82 6.77 -1.98 -3.69 307

TN2021-11

0-15 - - - - -

15-25 3.78 7.67 -3.78 -7.67 1

25-35 2.71 6.01 -0.78 -1 153

35+ 2.59 5.91 -2.02 -3.33 120

TN2021-12

0-15 - - - - - 15-25 5.87 8.83 4.85 6.37 11 25-35 1.82 5.39 1.3 3.79 147 35+ 1.13 4.38 -0.66 -1.59 69

TN2021-13

0-15 - - - - -

15-25 - - - - -

25-35 3.06 6.43 2.54 5 27

35+ 1.23 4.38 -0.2 0.02 428

SPEED

BIN

Data Quality Measures for

No. of Obs.

Avg. Absolute Speed Error Speed Error Bias

1.96 SEM Band Mean 1.96 SEM Band Mean

TN2021-14

0-15 0.07 0.91 0.02 -0.38 5

15-25 1.9 2.95 -0.61 -0.95 37

25-35 2.96 5.08 -0.66 -1.2 54

35+ 1.9 4.84 0.27 1.05 928

TN2021-15

0-15 - - - - -

15-25 - - - - -

25-35 19.47 27.28 19.47 27.28 1

35+ 4.74 9.24 -4.57 -8.62 511

TN2021-16

0-15 0.58 1.07 0.58 0.61 2

15-25 2.16 3.43 1.47 2.08 52

25-35 3.56 6.79 2.97 5.44 76

35+ 2.51 5.99 1.18 2.93 471

TN2021-17

0-15

15-25 1.27 2.96 0.66 0.6 48

25-35 1.02 3.61 -0.37 -1.19 272

35+ 2.35 6.1 -1.41 -3.89 53

TN2021-18

0-15 - - - - -

15-25 - - - - -

25-35 - - - - -

35+ - - - - -

TN2021-19

0-15 - - - - -

15-25 - - - - -

25-35 - - - - -

35+ - - - - -

TN2021-20

0-15 0.23 1.21 -0.23 -0.74 5

15-25 1.75 4.25 1.14 2 73

25-35 1.56 4.52 -0.08 0.07 230

35+ 3.28 7 -2.76 -5.56 30

TN2021-21

0-15 - - - - -

15-25 - - - - -

25-35 - - - - -

35+ 2.95 5.5 -1.56 -2.09 1189

TN2021-22

0-15 - - - - -

15-25 8.24 12.36 -5.06 -5.59 4

25-35 9.26 13 9.26 12.2 4

35+ 1.86 5.53 0.27 1.21 1174

TN2021-23

0-15 - - - - -

15-25 1.23 2.31 1.23 1.01 3

25-35 1.59 3.61 0.92 1.61 20

35+ 1.51 4.35 -0.12 -0.11 996

TN2021-24

0-15 - - - - -

15-25 - - - - -

25-35 - - - - -

35+ 2.56 6.08 -2.29 -4.91 328

TN2021-25

0-15 - - - - -

15-25 5.78 9.39 4.43 6.94 34

25-35 2.15 6.25 1.2 2.71 195

SPEED

BIN

Data Quality Measures for

No. of Obs.

Avg. Absolute Speed Error Speed Error Bias

1.96 SEM Band Mean 1.96 SEM Band Mean

35+ 1.53 4.98 -0.98 -2.22 36

TN2021-26

0-15 - - - - -

15-25 - - - - -

25-35 2.59 5.51 -0.58 -1.39 52

35+ 3.28 7.01 -2.46 -5.22 190

TN2021-27

0-15 - - - - -

15-25 - - - - -

25-35 2.84 5.98 -1.09 -2.64 16

35+ 2.91 6.28 -2.39 -4.27 190

TN2021-28

0-15 1.69 3.38 1.57 2.68 81

15-25 3.29 6.87 2.98 5.62 483

25-35 1.53 5.79 0.65 2.67 320

35+ 2.4 5.98 0.31 -0.17 16

TN2021-29

0-15 0.42 1.37 -0.05 -0.31 3

15-25 2.01 3.93 -0.35 -0.45 39

25-35 1.72 4.38 -0.01 0.05 445

35+ 2.09 5.4 -0.95 -2.46 273

TN2021-30

0-15 - - - - -

15-25 1.94 4.11 -0.1 -0.37 192

25-35 2.48 5.19 -0.14 -0.61 586

35+ 3.95 9.04 -2.44 -5.51 43

TN2021-31

0-15 - - - - -

15-25 1.29 3.29 0.38 0.5 206

25-35 1.37 4.3 -0.78 -2.24 558

35+ 2.61 6.14 -2.2 -4.01 49

TN2021-32

0-15 1.31 2.26 1.31 2.26 1

15-25 0.85 2.52 0.2 0.58 107

25-35 1.27 4.04 -0.48 -0.89 124

35+ 2.49 5.27 -2.44 -4.04 44

TN2021-33

0-15 - - - - -

15-25 2.62 6.88 1.98 5.8 30

25-35 1.04 4.8 0.71 2.13 246

35+ 1.19 6.2 -0.86 -3.81 112

TN2021-34

0-15 - - - - -

15-25 3.11 5.05 3.11 3.53 2

25-35 1.61 5.19 -0.88 -2.53 103

35+ 2.97 7.49 -2.97 -7.26 57

TN2021-35

0-15 2.09 4.07 2.09 4.07 2

15-25 1.59 4.4 1.07 3.07 120

25-35 1.62 4.08 -0.51 -1.04 53

35+ - - - - -

Daily Comparison Charts To visually inspect the quality of data, a set of 24-hour comparison graphs have been produced for each test segment. Sample graphs for the test segment TN2021-04 are presented in Figures 2 and 3. Figure 2 shows individual Bluetooth observations, filtered Bluetooth observations, NPMRDS data points and the 95% confidence band around the mean of Bluetooth speed for one day. Figure 3 shows the Bluetooth speed, NPMRDS speed as well as number of Bluetooth speed observations for each five-minute interval.

Figure 2 - Sample Bluetooth and NPMRDS graph for a test segment in Tennessee

Figure 3 - Sample Bluetooth count and Bluetooth / NPMRDS speeds for a test segment in Tennessee