Systems, methods, and devices relating to tracking a vehicle on its journey. At predetermined reporting time intervals, the vehicle's location is determined using GNSS and a current vector is calculated based on a current location and an immediately preceding location. The difference between the current vector and the immediately preceding vector is then determined and this difference is stored in the data packet. The data packet is transmitted to the base station using a two-way radio data link at select predetermined transmission time intervals. The data in the data packet is encoded to minimize the number of bits needed to store each data point.