The invention provides a method for determining a transportation direction (TD) for a user, the method comprising: receiving a current location (CL) of the user; receiving a pollution based input value (PIV) related to air pollution in a geographical area (GA) including the current location (CL); determining the transportation direction (TD) using the pollution based input value such that the user is subjected to a lowest level of pollution and/or such that a predefined maximum level of pollution to which the user is subjected is not exceeded; and retrieving a human activity based input value, wherein the human activity based input value is based on activity data from a portable device (