It is not uncommon in the field of traffic engineering for two-way roads to be converted to one-way roads and vice versa. In these situations the traffic engineer would be faced with the problem of selecting direction for each of the one-way roads. This problem is named the one-way road network problem in this thesis. By modelling the road networks as graphs, an algorithm (called 'conversion algorithm' in this thesis) is developed; this The author would like to extend his sincere gratitude to the following people: Supervisor, A/Prof Lew Sin Chye, for his guidance and contributions throughout this project.