All areas of the world that are part of the British Empire.
The British Empire is one of the three world superpowers left after the devastating actions of World War 2 following the collapse of Nazi Germany.
With much of mainland Europe left decimated the remaining governments in exile were formally annexed by Great Britain and British Forces quickly occupied the former Germany. This left Great Britain in a unique position at the end of the war with no opposition from anyone left in Europe they quickly formed a proper empire in Europe. With London being the seat of all power. The former European states such as France and Spain, were re-designated autonomous regions within the new empire.
The post war empire had a hard time reestablishing order, but eventually succeeded in a ultimately unstable world. They quickly moved to nationalize industry in the autonomous regions. Restarting the vast industrial sectors left over by the German war machine. We utilized the vast infrastructure that Nazi Germany had built when they still believed in the 1000 year Reich. With the integration of the former European states much of the world was now under the British Empire control. Most of the African continent and much of the middle east was now direct colonies of the empire with a few remaining countries managing to stay independent. The 1960's were a period of slow but ultimately fruitful growth for the new empire. Thanks to the ongoing cold war between the Japanese Empire and the U.S.A. alongside the barbarianism and lawlessness of the SOV-states. Air Travel for non millitarised purposes was deemed entirely useless. So towards the end of the 60's and into 70's we saw many new forms of transportation being trialed the most successful of which the Landrover/Rolls-Royce Landtrain.