Vehicles, such as buses which are massive and have a very high centre of gravity, they have a lower resistance to overturning than other vehicles. The studies have shown that deformations can especially occur in the body structure. Some deformations that can occur in carrier elements during an accident make the vehicle a vital danger area for drivers and passengers. The aim of this study is to examine the protection of the passengers in the bus by means of constructive developments to be made within the body structure. ECE R66 legal regulations which are issued by the European Union (EU) and (Economic Commission for Europe Regulation 66- Provisions on the Approval of Major Passenger Vehicles for Resistance to the Construction of the Skeleton) for the buses were developed to protect passengers’ habitats in overturning accidents. This work focuses to reach constructive solutions for costing, manufacturing and, safety which provided conditions for the body structure during rollover behaviour of the vehicle. Computer simulations and analysis have been performed to examine the strength of the cross-section of the body structure. The methods specified in the standard for calculating the rollover behaviour of the vehicle have been implemented and concluded. The results obtained from all these analyses produced constructive solutions and optimizations for the design of intercity buses.