Travel Time Reliability Reference Manual/Data Format and Size

NPMRDS Data FormatEdit

NPMRDS data comes in two formats. The first is the static file containing the TMC information for all states. This file may be updated from time to time, but is typically static. The remaining files contain the travel time information for each state in the form of comma separated files (CSV). The files are usually between 500MB and 4GB depending on the region, with the Northeast being the largest data set.

A sample Google Earth (.kml) file mapping out the TMCs in Iowa, Minnesota, North Dakota, South Dakota and Wisconsin is available here or on Google Maps here .

TMC Static File Format

Field Name Type Example Description
TMC Text D01N04474 Traffic Location code in the format of:

CLLDTTTTT

Where:

  • C is the Country Code (1 digit)
  • LL is the Location Table Number (2 digits)
  • D is the TMC path direction ('P' or 'N')
    • N refers to negative direction of the TMC
    • P refers to positive direction of the TMC
  • TTTTT is the TMC location code (5 digits)

If no data exists for a TMC for an epoch, there will be no entry in the data file for that combination of TMC/day of week/epoch.

ADMIN_LEVEL_1 Text United States The Country where the listed Traffic Location Code is located.
ADMIN_LEVEL_2 Text Illinois The State / Province where the listed Traffic Location Code is located.
ADMIN_LEVEL_3 Text DuPage The County where the listed Traffic Location Code is located.
DISTANCE Float 3.27285 The length of the TMC, measured in Miles to five decimal places.
ROAD_NUMBER Text I-90 Road Number taken from Location Table. When a Road has both a route number and local name, the route number is placed in the Road Number column and the local name in the Road Name column.
ROAD_NAME Text S ARCHER AVE Road Name taken from Location Table. When a Road has both a route number and local name, the route number is placed in the Road Number column and the local name in the Road Name column.
LATITUDE Float 37.87472 WGS84 coordinate to five decimal places

Note: latitude & longitudes provided will be for the beginning of the TMC.

LONGITUDE Float -122.18671 WGS84 coordinate to five decimal places

Note: latitude & longitudes provided will be for the beginning of the TMC.

ROAD_DIRECTION Text NORTHBOUND Road direction represents the direction of travel based on the road sign

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Travel Time File Format

Field Name Type Example Description
TMC Text D01N04474 Traffic Location code in the format of:

CLLDTTTTT

Where:

  • C is the Country Code (1 digit)
  • LL is the Location Table Number (2 digits)
  • D is the TMC path direction ('P' or 'N')
    • N refers to negative direction of the TMC
    • P refers to positive direction of the TMC
  • TTTTT is the TMC location code (5 digits)

If no data exists for a TMC for an epoch, there will be no entry in the data file for that combination of TMC/day of week/epoch.

DATE Text 04022012 Day Month Year (DDMMYYYY)
EPOCH Integer 48 A value from 0 through 287 that defines the 5-minute period the average speed applies (local time), where:

0 = 00:00:00 to 00:04:59 1 = 00:05:00 to 00:09:59 2 = 00:10:00 to 00:14:59 … 287=23:55:00 to 23:59:59

Travel_TIME_ALL_VEHICLES Integer 44 In seconds.

Travel times are calculated as the ratio between the segment length and the average speed on the segment. Average segment speed is determined from a combination of the passenger and freight trucks individual GPS probe speed observations.

Travel_TIME_PASSENGER_VEHICLES Integer 76 In seconds.

Travel times are calculated as the ratio between the segment length and the average speed on the segment. Average segment speed is determined from only passenger individual GPS probe speed observations.

Travel_TIME_FREIGHT_TRUCKS Integer 1 In seconds.

Travel times are calculated as the ratio between the segment length and the average speed on the segment. Average segment speed is determined from only freight trucks individual GPS probe speed observations.

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ReferencesEdit