'Guideline of performance-based design for steel structure' has been developed to introduce the PBD code for steel structure design in Korea. This guideline includes various innovative design concepts and standardized methodologies and provides more obvious and practical guidance to the PBD process. A simple procedure to perform vibration serviceability evaluation for bridges is introduced proposing a new concept of artificial wheel load generation technique, by which the dynamic responses of bridges due to the heavy vehicles traveling on the decks with surface roughness can be calculated with the commercial programs. Based on the LCC analysis, the procedure to select optimum target reliability level and the procedure to adjust the LRFD formats to achieve the selected target reliability level by modifying either load factors or resistance factor are presented. A traffic control system is proposed to control the headway distance between the consecutive heavy vehicles and reduce effectively the maximum traffic load effects in the bridge. The design live loads for long span bridges can be reduced effectively while maintaining the desirable life cycle safety level.