As our cities become more populous, it is becoming more common to develop housing around and over transport hubs, including over and adjacent electrified railways. These over site and adjacent to the railway corridor developments present challenges for the design of the earthing system for the electrical installations supplying the developments. An electrified railway, whether AC or DC, will give rise to traction return currents that will flow via the ground and may impact on the electrical installations of the developments. The issues that arise due to an electrified railway may not be immediately obvious to designers of electrical supply and installations for developments, unless they have come across the issues previously, or the approvals process dictates considerations be made. However, once identified, various design solutions are available to minimise the impacts of the railway traction systems on people and the infrastructure of the developments over and adjacent to the electrified rail corridor.