A self-declaring device adapted to be installed on a vehicle, comprising: a sensor module configured to collect data from inside the vehicle, the sensor module comprising a plurality of sensors including at least a first sensor and a second sensor, wherein the first sensor is configured to collect the data from inside the vehicle during a first period of day and the second sensor is configured to collect the data from inside the vehicle during a second period of the day; a wireless transceiver comprising a plurality of operation states and configured to communicate with an electronic toll collection system using one or more of the plurality of operation states, wherein the operation states of the wireless transceiver include at least one of an ON/OFF state of the wireless transceiver and a plurality of operation frequencies of the wireless transceiver; and a microcontroller coupled to both the sensor module and the wireless transceiver and configured to: receive at least a portion of data collected by the sensor module; determine occupancy data based at least in part on the at least a portion of data; determine an operation state of the wireless transceiver from the plurality of operation states based at least on the determined occupancy data; change the operation state of the wireless transceiver to the determined operation state in response to the determination; and communicate the occupancy data with a reader of the ETC system using the determined operation state of the wireless transceiver, wherein if the determined operation state is the OFF state, communication with the ETC system is disabled and, if the determined operation state is the ON state, communication with the ETC system is enabled. a sensor module configured to collect data from inside the vehicle, the sensor module comprising a plurality of sensors including at least a first sensor and a second sensor, wherein the first sensor is configured to collect the data from inside the vehicle during a first period of day and the second sensor is configured to collect the data from inside the vehicle during a second period of the day; a wireless transceiver comprising a plurality of operation states and configured to communicate with an electronic toll collection system using one or more of the plurality of operation states, wherein the operation states of the wireless transceiver include at least one of an ON/OFF state of the wireless transceiver and a plurality of operation frequencies of the wireless transceiver; and a microcontroller coupled to both the sensor module and the wireless transceiver and configured to: receive at least a portion of data collected by the sensor module; determine occupancy data based at least in part on the at least a portion of data; determine an operation state of the wireless transceiver from the plurality of operation states based at least on the determined occupancy data; change the operation state of the wireless transceiver to the determined operation state in response to the determination; and communicate the occupancy data with a reader of the ETC system using the determined operation state of the wireless transceiver, wherein if the determined operation state is the OFF state, communication with the ETC system is disabled and, if the determined operation state is the ON state, communication with the ETC system is enabled. receive at least a portion of data collected by the sensor module; determine occupancy data based at least in part on the at least a portion of data; determine an operation state of the wireless transceiver from the plurality of operation states based at least on the determined occupancy data; change the operation state of the wireless transceiver to the determined operation state in response to the determination; and communicate the occupancy data with a reader of the ETC system using the determined operation state of the wireless transceiver, wherein if the determined operation state is the OFF state, communication with the ETC system is disabled and, if the determined operation state is the ON state, communication with the ETC system is enabled.