A computer implemented method, the method comprising: receiving information of a location or movement of a transport chassis, the transport chassis being configured to carry a cargo transportation unit, CTU; and using the received information of a location or movement to trigger a determination of whether the transport chassis is loaded with a CTU or a cargo, wherein determining whether the transport chassis is loaded with the CTU or the cargo comprises: receiving measurement data from a sensor of the transport chassis; accessing a profile learned based on past measurement data, the profile comprising a range of measurement data values indicating that the transport chassis is loaded; and determining, based on the measurement data and the profile, whether the transport chassis is loaded with the CTU or the cargo, said determining comprising determining that the measurement data is within the range of measurement data values wherein measurement data is from either: an optical sensor of the transport chassis, the measurement data comprising a characteristic of an optical signal; or a magnetic field sensor of the transport chassis, the magnetic field sensor being configured to measure a distortion of the magnetic field by the presence of the CTU or the cargo. receiving information of a location or movement of a transport chassis, the transport chassis being configured to carry a cargo transportation unit, CTU; and using the received information of a location or movement to trigger a determination of whether the transport chassis is loaded with a CTU or a cargo, wherein determining whether the transport chassis is loaded with the CTU or the cargo comprises: receiving measurement data from a sensor of the transport chassis; accessing a profile learned based on past measurement data, the profile comprising a range of measurement data values indicating that the transport chassis is loaded; and determining, based on the measurement data and the profile, whether the transport chassis is loaded with the CTU or the cargo, said determining comprising determining that the measurement data is within the range of measurement data values receiving measurement data from a sensor of the transport chassis; accessing a profile learned based on past measurement data, the profile comprising a range of measurement data values indicating that the transport chassis is loaded; and determining, based on the measurement data and the profile, whether the transport chassis is loaded with the CTU or the cargo, said determining comprising determining that the measurement data is within the range of measurement data values wherein measurement data is from either: an optical sensor of the transport chassis, the measurement data comprising a characteristic of an optical signal; or a magnetic field sensor of the transport chassis, the magnetic field sensor being configured to measure a distortion of the magnetic field by the presence of the CTU or the cargo. an optical sensor of the transport chassis, the measurement data comprising a characteristic of an optical signal; or a magnetic field sensor of the transport chassis, the magnetic field sensor being configured to measure a distortion of the magnetic field by the presence of the CTU or the cargo.