Use of Bluetooth-based Data Collection Opportunities and Challenges for

Urban Corridor Studies

Donna Nelson, PhDMarketing Director, Traffax Incdcnelson@traffaxinc.com240-447-8612

BluFax Technology

Distance

Each Bluetooth devices has a unique, but anonymous device ID

BluFax devices record:ID of each detectable device.Time stamp ID detected.BluFax unit IDBluFax location coordinates.

BluStat Software:Processes station data.Filters and processes data.Outputs graphics and results.User-configurable parameters.

Detection Zone

At least two units are required! Number of units and spacing depends on application.

Time and Space

Segment: Pairs of units

All BluFax applications build on the concept of comparing the time at which unique device IDs are detected by pairs of units.

Stations-BluFax units

A

GD

A B C

EH

D

D

Corridor: Defined by a series of segmentsO-D Pairs: Defined between pairs of stations to capture Origins & Destinations.

EARLY APPLICATIONS…….Early applications focused on vehicle traveltime applications on freeways, arterial roadways, and special events.

04/10/20234

I-95 Vehicle Probe ValidationAssessment of signal timing on arterialsUrban arterials, DC Demo on July 4th

Freeway Interchange AssessmentBrickyard (Indianapolis) StudyPassenger delay at security check pointsTraveltime studies in Australia

Recent Applications

Evolving Application types• Traveltime and delay studies• Real-time traveltime information. • Signal timing before and after studies.• Evaluation of complex interchanges• Pedestrian origin-destination studies.• Passenger wait times and border wait

times. (real time and lane-by-lane)• Work zone monitoring (real time)• Workzone operations evaluation• Access/egress private developments• Large-scale planning O-D studies

Application environments• Freeways• Arterial roadways• High-density urban

environments.• Workzones• Transit stations/pedestrian zones.• Intersections• Freeway interchanges• Access/egress

Rapid shift from traveltime to applications requiring a combination of O&D and travel time capabilities.

Key Characteristics

Picks ups all signals within its detection zone.

Ability to track unique signal past detectors throughout study area.

The majority of detectable devices are carried by an individual who may be on foot, in an automobile, truck, bus, or the local coffee shop; or vehicles in main lanes and adjacent HOV lanes.

Volume Population w/ devices

Station Detection

Matched Pairs Sample

Data from BluFax represents a SAMPLE of the population

4th of July Demonstration 2009• Operation Fast Forward

– Collect traffic data following special events.– Data collection following closure of 4th of July

fireworks at the National capital Mall.– Develop and evaluate emergency management

plans and models.

• Traditional traffic studies– Provide insufficient data to support analysis

and modeling needs.– Manual data collection for pedestrians

labor intensive and expensive.– Typical data collection limited to three

hours following close of fireworks.

5 Minute Detection Rates

0 to 18

0 to 50

0 to 80

0 to 65

Segment Plot Results by Day

12 AM 3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM 12 AM0

10

20

30

Tra

vel T

ime

- M

inut

es

TRAVEL TIME :: Segment BE9-D5B Freeway b-c :: 05-Nov-2008

Bluetooth Data

Bluetooth Mean

12 AM 3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM 12 AM0

20

40

60

80

100

Spe

ed -

MP

H

SPEED based on a distance of 3.9989 miles

Bluetooth Data

Bluetooth Mean

12 AM 3 AM 6 AM 9 AM 12 PM 3 PM 6 PM 9 PM 12 AM0

5

10

15

20

25DETECTION RATE

Bluetooth 5 min detection rate

Travel time

Speed

Matched pairs

Un-filtered Traveltimes

Arterial Analysis

• MD24 in Northern Baltimore• Before/After impact of signal timing• AM, Mid-day, and PM analysis• February 23-27, 2009

– New timing on 2/25/09

E

B

C

F

D

A

G

Intersections and InterchangesTurning movement proportions and travel-time (delay) through interchanges, intersections, and roundabouts are measured by placing BluFax units at each approach.

A complex interchange is treated like a small-scale O-D study.

All twelve movements for a complex interchange can be captured with as few as four units.

The key is to ensure that sample sizes on each segment are sufficient for your study needs.

Once units are in place, the additional costs associated with collecting from 1 to 14 days of data are minimal.

Opportunities

Provides space mean speed which reflects the time needed to traverse a defined section of roadway.

Corridor data addresses traveltime or speed along defined corridors.

Can be defined to reflect different entry/exit points along corridors, or to compare alternate corridors.

Origin-Destination Data BluFAX provides origin/destination data with a time element

Volumes and Detection Rates

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BluFAX does not collect traffic volumes, however,

Studies indicate that detection rates track to volumes for comparable time periods.

Proportion of turning movements for arterial intersections and interchanges support this…..

Detections can be compared to volume counts to establish a baseline for a specific location.

Bluetooth, Floating Car, Inrix Data

Comparison with ATRs

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Comparison of BluFAX data with ATR data…..

Speed

Proportion of volume by time of day

Pedestrian Station Detections

4:00 AM

4:45 AM

5:30 AM

6:15 AM

7:00 AM

7:45 AM

8:30 AM

9:15 AM

10:00 AM

10:45 AM

11:30 AM

12:15 PM

1:00 PM

1:45 PM

2:30 PM

3:15 PM

4:00 PM

4:45 PM

5:30 PM

6:15 PM

7:00 PM

7:45 PM

8:30 PM

9:15 PM

10:00 PM

10:45 PM

11:30 PM

12:15 AM

1:00 AM

1:45 AM

2:30 AM

3:15 AM

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

BluFax Detections and Turnstile CountsTuesday 6/15 and Wednesday 6/16

Date and Time Filters

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Origin-Destination Reporting ParametersMETHOD DATE_TIME_FILTEREDDATETIME BEGINDATETIME ENDSEARTCHTIME MINIMUM 0:00:00SEARCHTIME MAXIMUM 3:00:00

Status of O-D PairsEND STATION

BEGIN STATION UNIT A UNIT B UNIT CUNIT A OK OK OKUNIT B OK OK OKUNIT C OK OK OK

O-D DataEND STATION

BEGIN STATION UNIT A UNIT B UNIT CUNIT A 4273 4293 2132UNIT B 3652 1081 82UNIT C 2375 96 705

11/5/2008 0:0011/5/2008 23:59

Date_Time filter settings depend on purpose of study.

Segment with the same beginning and end point, and longer time window, provides O-D information for vehicles entering and leaving via the same route.

Planning or Traffic?

• Filtering criteria– Min/max travel times– Specific segments (station pairs)– Placement of units– Density/spacing of units

The concept can be applied to planning or traffic applications.

Often, the same data set and support both types of studies!