Conversion of Volunteer-Collected GPS Diary Data into Travel Time Performance Measures Research Project Conducted for PC : Terry Keener PD : Michael Chamberlain PI : Chandra R. Bhat Barbara Parmenter Researchers Siva Srinivasan Prabuddha Ghosh Aruna Sivakumar Aarti Kapur Stacey Bricka Training Workshop on the Use of GPS-TDG Software

Presentation Overview Background Research Objectives Conceptual Structure of GPS-TDG Software Overview Tutorial using Sample Data from Laredo Preprocessing GPS streams Basic Analysis Enhanced Analysis Querying and Aggregation

Background: Collecting Travel Data Travel Demand Models Forecast Travel Demand Understand Travel Needs: Generate Policy Actions Evaluate Impacts of Policy Actions Household Travel Surveys Data

Background: Enhancing Travel Data Collection Survey Design Enhancements Trip diaries Activity diaries Time-use diaries Survey Implementation Enhancements PAPI CATI ETD / CASI GPS-Enhanced

Using GPS in Travel Surveys: Different Technologies In-Vehicle devices Hand-held devices Purely passive Requiring additional active input Our focus

Advantages of GPS-based Data Collection Passive Data Collection Reduces respondent burden Address under-reporting of trips Address item non-response Increased Spatial and Temporal Accuracy Destination locations for non-frequent trips Trip times and time-of-day of travel are not estimates Additional Data Trips missed in manual reporting Route choice Travel speeds

Issues with Passive-GPS Data Collection Data is collected in the form of navigational streams Requires operational definitions of “ trips ” and “ stops ” Requires substantial processing for converting into conventional trip-diary format Equipment capabilities/accuracy/errors impacts trip identification Trip purpose information unknown Requires supplemental user input (en-route or via prompted recall) Use of regional land-use and respondent demographics data for imputing trip purposes Vehicle occupancy unknown Requires supplemental user input

GPS-based Travel Surveys: Summary Substantial potential for using in-vehicle GPS technologies in travel surveys to enhance quality and quantity of data Shifts considerable burden from the respondent to the analyst: Need to convert navigational streams from GPS devices to trip sequences

Research Objectives 1)Develop algorithm to identify vehicle trip characteristics from GPS navigational streams 2)Implement the algorithm in GIS-based software to automate travel-diary extraction 3)Aggregate the derived travel diaries to produce inter-zonal trip- tables by trip purpose and time of day 4)Compute inter-zonal highway performance measures (i.e., travel times and speeds) Develop a GIS-based software to automate the process of converting the raw GPS navigational streams into the conventional trip-diary format

Conceptual Overview of GPS-TDG

GPS-TDG: Primary User Interface Data Area Display of derived travel diaries and query results Command Area Providing inputs, querying, and overall control Menu Bar Preprocessing and help

1.View sample raw GPS streams 2.Preprocess GPS streams & view the results 3.Running the software in the Basic Analysis mode Provide inputs View and interpret results 4.Running the software in the Enhanced Analysis mode Provide inputs View and interpret results 5.Aggregation and Querying Tutorial on Using GPS-TDG

Sample Raw GPS Stream (GeoLogger) RECTYPE,GPS_ID,HH_ID,Veh_ID,GMT_DATE,GMT_TIME,LOC_DATE,LOC_TIME,LAT_RAW,LONG_RAW,ELEV_RA W,VELOCITY,HEADING,HDOP,SATS 5,272, ,1,03/25/02,12:40:37,03/25/02,06:40:37, , ,00179,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:38,03/25/02,06:40:38, , ,00179,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:39,03/25/02,06:40:39, , ,00180,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:40,03/25/02,06:40:40, , ,00180,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:41,03/25/02,06:40:41, , ,00180,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:42,03/25/02,06:40:42, , ,00180,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:43,03/25/02,06:40:43, , ,00179,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:44,03/25/02,06:40:44, , ,00179,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:45,03/25/02,06:40:45, , ,00179,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:46,03/25/02,06:40:46, , ,00178,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:47,03/25/02,06:40:47, , ,00178,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:48,03/25/02,06:40:48, , ,00177,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:49,03/25/02,06:40:49, , ,00177,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:50,03/25/02,06:40:50, , ,00177,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:51,03/25/02,06:40:51, , ,00176,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:52,03/25/02,06:40:52, , ,00176,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:53,03/25/02,06:40:53, , ,00176,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:54,03/25/02,06:40:54, , ,00176,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:55,03/25/02,06:40:55, , ,00176,0.00,000,01.7,05 5,272, ,1,03/25/02,12:40:56,03/25/02,06:40:56, , ,00175,0.00,000,01.7,05

Running the Preprocessor Select the directory containing the raw streams Select the target directory for writing the processed streams

HREC,HDOP=5.0,Min Satellites=3 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 GREC,272, ,1, , , ,0.00,000,0 Sample Processed GPS Stream

Click button, navigate to appropriate input files, and select Click button, navigate to directory containing pre-processed GPS streams and select Leave blank to use default algorithm parameters Click to run the trip detection after providing all inputs Provide file name to store the derived travel diaries Basic Analysis

Basic Analysis: Results

Enhanced Analysis Click button, navigate to appropriate input files, and select Additional inputs for enhanced analysis Progress bar

Enhanced Analysis: Results

Querying and Aggregation: Options Aggregation criteria Filtering criteria Input: a file containing derived travel diaries

Querying and Aggregation: Results Overall aggregation summary

Querying and Aggregation: Results Trip table and inter-zonal performance measures (over entire day and all trip purposes)

Querying and Aggregation: Results Trip table and inter-zonal performance measures (PM peak, all trip purposes)

Querying and Aggregation: Results Trip table and inter-zonal performance measures (entire day, home-based work trips)

Thank You!

Structure of GPRMC Streams

Structure of GeoLogger Streams

Algorithm Parameters

Accept inputs Read in data for first/next vehicle Scan GPS stream until a potential trip is detected Compute trip characteristics Perform reasonableness checks Check if end of GPS stream is reached for the current vehicle Write trip to output file Check if there are any more vehicles in the database Potential trip passes checks Potential trip fails checks Yes No Trip diary extraction complete No Conceptual Overview of Process Module

Attributes Characterizing Each Trip in the Derived Travel Diary Database