This study presents a user interactive computer program for the design and configuration arrangement of a 33/11 kV substation earthing grid system within restricted areas such as the cases of Benin city injection substations. The study is aimed at the creation of awareness on safe substation earthing grid system design. The provision of earthing systems is not only for the protection and proper functioning of substation equipments, but also for the safety of personnel during earth faults and lightning strikes. Standard expressions taken from IEEE 80 and 2000 are used in writing an interactive programme for the simulation of touch, step and mesh potentials of substation earthing grid, which are the most important factors for personnel safety in and around substations. The interactive program follows an algorithm that gives the final design configuration and the total required conductor length that satisfied the criterion for safety.