- Summary
- Data Filtering
- File Content Description
- Data Size
- Variables
- Reference
- Coordinate Reference System
This document describes the UMTRI MAP dataset that is available on Flux through Globus Connect. The data represents the MAP messages used to provide intersection and roadway lane geometry data for one or more locations. Almost all roadway geometry information as well as roadway attributes (such as where a do not block region exists, or what maneuvers are legally allowed at a given point) is contained in the “generic lane” details of this message. MAP messages are used in intersections to number and describe lane level details of each lane, while the SPAT message provides the current state of each signal head controlling the ability to stop/pass a given lane.
Since MAP messages do not change (since intersection geometry is constant barring significant construction), the dataset only contains a single instance of that message to reduce redundancy.
The table represents the MAP messages available that are transmitted by Roadside Equipment (RSE) devices in the Plymouth Road corridor.
| RxDevice | Location | MapMD | AEB | Lane | Node |
|---|---|---|---|---|---|
| 18010 | Plymouth and Barton | Yes | No | No | No |
| 18012 | Plymouth and Traverwood | Yes | Yes | Yes | Yes |
| 18013 | Plymouth and Nixon | Yes | Yes | Yes | Yes |
| 18014 | Plymouth and Huron Parkway | Yes | Yes | Yes | Yes |
| 18015 | Plymouth and Green | Yes | Yes | Yes | Yes |
| 18022 | Plymouth and Murfin | Yes | No | No | No |
No filtering has been done to MAP messages.
Each file is comma delimited. Files do have column headers.
The total size of the dataset is a tiny 8 KB (see summary for reason).
Here is the variable definitions for the four MAP data files.
The RxDevice column represents the primary key for the dataset.
| Column Number | Name | Description | Units |
|---|---|---|---|
| 1 | RxDevice | device Id of the RSE | none |
| 2 | FileId | unique number assigned to each file; not the same FileId in the BSM dataset | none |
| 3 | TxDevice | another RSE Device Id | none |
| 4 | Gentime | number of microseconds since Jan 1, 2004 (UTC +00:00) | microseconds |
| 5 | MsgCount | MAP message count (restarts with new pcap file) | none |
| 6 | FrameOffset | ||
| 7 | FrameSize | ||
| 8 | MapRelOffset | ||
| 9 | MapPayLoad | ||
| 10 | GenTimeRelOffset | ||
| 11 | Version | ||
| 12 | MessageAttr | ||
| 13 | Latitude | y-reference point of intersection | degrees |
| 14 | Longitude | x-reference point of intersection | degrees |
| 15 | Elevation | z-reference point of intersection | |
| 16 | AEBCount |
The RxDevice column represents the primary key for the dataset.
| Column Number | Name | Description | Units |
|---|---|---|---|
| 1 | RxDevice | device Id of the RSE | none |
| 2 | FileId | unique number assigned to each file; not the same FileId in the BSM dataset | none |
| 3 | TxDevice | another RSE Device Id | none |
| 4 | MsgCount | MAP message count (restarts with new pcap file) | none |
| 5 | AEBCount | ||
| 6 | AEBType | ||
| 7 | LaneCount | Number of lanes in intersection | lanes |
| 8 | PriPreLoad |
The RxDevice and Lane columns represents the composite primary keys for the dataset.
| Column Number | Name | Description | Units |
|---|---|---|---|
| 1 | RxDevice | device Id of the RSE | none |
| 2 | FileId | unique number assigned to each file; not the same FileId in the BSM dataset | none |
| 3 | TxDevice | another RSE Device Id | none |
| 4 | MsgCount | MAP message count (restarts with new pcap file) | none |
| 5 | AEB | ||
| 6 | Lane | lane number | none |
| 7 | LaneType* | 1-motorized vehicle lane, 2-computed lane, 3-pedestrian lane, 4-special purpose lane | none |
| 8 | LaneId | lane Number (same as column 6) | none |
| 9 | LaneAttr* | unsigned 16-bit integer describing the lane attributes | none |
| 10 | BarrierAttr* | unsigned 16-bit integer describing the barrier attributes | none |
| 11 | Width | lane or barrier width | cm |
| 12 | ConnLaneId | lane id of a previously defined lane to which this lane connects | lane |
| 13 | ConnCode* | unsigned 8-bit integer describing the maneuver code | none |
| 14 | RefLaneId | lane id of reference lane that a computed lane parallels | none |
| 15 | RefLatOffset | signed 16-bit integer describing the lateral offset of reference lane | cm |
| 16 | NodeLoad | ||
| 17 | NodeAttr | unsigned 8-bit integer describing the node attributes | none |
| 18 | NodeNumOfPts | Number of nodes in each lane | nodes |
*Bit values for these columns can be found in the reference documentation mentioned below.
The RxDevice, Lane, and Node columns represents the composite primary keys for the dataset.
| Column Number | Name | Description | Units |
|---|---|---|---|
| 1 | RxDevice | device Id of the RSE | none |
| 2 | FileId | unique number assigned to each file; not the same FileId in the BSM dataset | none |
| 3 | TxDevice | another RSE Device Id | none |
| 4 | MsgCount | MAP message count (restarts with new pcap file) | none |
| 5 | AEB | ||
| 6 | Lane | lane id | none |
| 7 | Node | node id | none |
| 8 | NodeEastOff | node eastern offset relative to the intersection reference point | cm |
| 9 | NodeNorthOff | node northern offset relative to the intersection reference point | cm |
| 10 | NodeEleOff | node elevation offset relative to the intersection reference point | cm |
| 11 | NodeWidth | lane width at node location | cm |
Note: Missing descriptions mean I did not find a good reference in the documentation to explain the column.
Variable definitions were taken from the Word document J2735_SPATblob_MAPblob_RevC_20120217.docx in the TripStart/map/documentation folder.
GPS coordinates are in WGS84 or EPSG:4326