Worldwide, 50% of the population already live in cities, and this percentage is expected to rise. Cities account for an estimated 70% of both energy use and fossil fuel CO2 emissions, and urban passenger travel forms a significant share of this total. This paper introduces a novel approach for reducing both the energy and resulting carbon emissions from such urban travel, in the form of a personal transport energy quota, using a unique cloud technology based intelligent navigation system. The approach has some similarities to the Personal Carbon Trading scheme proposed for the UK some years ago, but is for personal transport only. Like carbon taxes, which have now been introduced in a number of countries/regions, this UK scheme aimed at reducing carbon emissions. The approach proposed in this paper would grant a monthly transport energy quota to all residents. A mobile phone-based application would provide the user with details on the energy costs of each trip, the remaining energy quota at any time, and suggest alternative travel options to minimise trip energy use.