An asset's TCU, or a mobile device coupled thereto, receives and stores geographical boundary definitions to a memory. A processor uses the boundary definition to determine an initial-location boundary based on the definition and the current location of the TCU at the time it received the boundary request message. As the TCU's GPS unit generates location information, the processor retrieves the initial-location boundary definition from the memory and compares the current location from the GPS receiver to it according to an algorithm. If the processor determines that the current location of the vehicle has crossed the boundary, the processor generates an alert message, which may be an e-mail, SMS, telephonic, interne, IM, or other electronic message indicating that an asset crossed the boundary, and sends it wirelessly using a transceiver to a central computer for further processing, or directly to another device, according to a notification destination identifier.