Public transport safety is an important issue that has recently gained large attention, especially with the rise of violence happening abroad. To avoid such incidents and to perform post-incident investigations, many buses today are equipped with surveillance cameras. These cameras are usually in stalled at important places such as doors, the front and the middle of the bus. This camera placement is often performed manually based on human intuition and knowledge; however, there is no scientific basis to justify: 1) how many cameras would be sufficient, and 2) where they should be placed, to increase the area of coverage at a minimum cost. In this pa per we present this as an optimization problem and propose a method to compute the approximate coverage of a camera inside the 3D bus model. The utility of proposed method is demonstrated for a single camera setup.