"Taxis are interesting environments in that they are often treated as a temporary private space - in which people can relax and objects are likely to spread out within the natural boundaries of the environment. When combined with other parameters such as: people using taxi’s whilst tired or impaired e.g. drunk/high; the likelihood of using the mobile phone in the taxi; placing objects on the seat/out of sight after use; and a pressured sequence of tasks at the end of the journey such as thinking what to do next on arrival at the destination and paying the driver, help explain why mobile phones are often left in taxis."