Travel Time Reliability Reference Manual/Data Format and Size
NPMRDS Data Format edit
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:
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:
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. |
Previous Page → Accessing the Data
References edit
- ↑ a b NPMRDS Specification Document (http://www.ops.fhwa.dot.gov/freight/freight_analysis/perform_meas/vpds/npmrdsfaqs.htm)