Table 2.

Description of the RAVL data structure.

Field	Description (Size)
RAVLVeh	Vehicle identifier. (2 bytes)
RAVLT	GPS Time of day expressed in Coordinated Universal Time (UTC). (4 bytes)
RAVLLat	Latitude of the vehicle expressed in degrees. (4 bytes)
RAVLLong	Longitude of the vehicle expressed in degrees. (4 bytes)
RAVLAlt	Altitude of the vehicle position expressed in feet. (4 bytes)
RAVLVel	Horizontal speed of the vehicle expressed in miles per hour. (2 bytes)
RAVLAge	Age of the GPS data:    0: data not available    1: >10 s    2: <10 s (1 byte)
RAVLSou	Type of position measurement:    0: data not available    1: 2D GPS    2: 3D GPS (1 byte)