Travel Time Reliability Reference Manual/Data Format and Size

NPMRDS Data Format

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

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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