| Abstract | The construction industry has been globally regarded as a relatively hazardous industry. It has always been reported that fatal accidents and injuries in construction remain consistently at a very high level despite a significant downward trend in recent years. Similarly, in Thailand, the construction industry has faced a wide range of challenges, one of which is the frequent occurrences of accidents at the workplace. Safety programs are now considered to be one of the most important approaches to eliminating work-related accidents and injuries. An effective safety program can substantially reduce accidents because it can help management build up safer ways to operate and create safe working environments for the workers. The Thai Government has taken significant steps to improve safety in the construction industry by promoting the establishment of safety programs at the enterprise level. It has been suggested that the following 17 safety programs should be implemented as business core functions: safety policies, safety committees, safety inductions, safety training, safety inspections, accident investigations, first aid programs, in-house safety rules, safety incentive schemes, control of subcontractors, selection of employees, personal protection programs, emergency preparedness planning, safety-related promotions, safety auditing, safety record keeping, and job hazard analysis. However, the accident occurrence rate in the construction industry still remains at unacceptable levels. This shows that the industry suffers from an inability to implement safety programs which achieve improved safety performance. To help the industry, therefore, it is worthwhile to conduct research focused on investigating effective and efficient safety programs, and identifying the key factors influencing the success of safety programs. The findings therefore can be used as a guideline by construction sites to implement safety programs successfully. This study was conducted with 35 medium and 35 large-scale construction projects taking part. To assess safety programs, an evaluation tool was developed by using scientific methods based upon Thai safety regulations and standards, and which was validated by a panel of safety experts. Multiple regression analysis was used to create models that reflect a set of the most effective and efficient safety programs for safety performance improvement. The effectiveness of safety programs was evaluated by studying the relationship between their actual status and associated site safety performance. It was found that 4 of the 17 safety programs, namely accident investigations, safety inspections, control of subcontractors, and safety incentives, are the most effective in reducing accident rates at construction sites. The most effective safety programs in minimizing the occurrence of unsafe acts at construction sites are safety inspections, accident investigations, control of subcontractors, and safety incentives. And lastly, accident investigations, safety inspections, job hazard analysis, safety inductions, and safety auditing were the most effective factors in eliminating unsafe conditions at construction sites. To evaluate the efficiency of safety programs, this study quantified amounts of staff time and budget allocated for safety program implementation based upon the perception-based survey and correlated them with safety performance. Multiple regression analysis yielded models which showed that 5 of the 17 safety programs, namely accident investigations, control of subcontractors, safety incentives, safety inspections, and safety auditing were the most efficient in improving accident rates. The most efficient safety programs in preventing the occurrence of unsafe acts were accident investigations, job hazard analysis, in-house safety rules, safety inspections, safety committees, and safety incentives. Lastly, safety committees, safety incentives, accident investigations, safety auditing, and safet) inspections were found as the most efficient factors in controlling unsafe conditions on th~ sites. Furthermore, this research also investigated critical success factors (CSFs) for safet) programs. These CSFs are important to guide contractors to implement safety program~ successfully. The CSFs are regarded as the limited number of activities in which results, i: they are satisfactory, will ensure successful implementation of safety programs. Therefore the final output of this study will enable contractors to choose effective and efficient safet~ programs and to implement them by understanding the CSFs. This study showed tha management support, appropriate safety education and training, teamwork, clear an< realistic goals, and an effective enforcement scheme were perceived by the respondents a: the most significant factors that need considerable attention in order to ensure successfu safety programs. However, this study found the current problems which may lead to failun of safety programs were lack of management support, lack of appropriate supervision, lad of sufficient resource allocation, lack of teamwork, and lack of effective enforcement Improving these priority factors to satisfactory levels would lead to successful safet: programs, thereby minimizing accidents. In conclusion, in light of this research, a package of comprehensive strategies for achievin: improved construction safety performance was provided. In other words, the study gave set of the most effective and efficient safety programs for implementation on constructio: sites as well as critical activities or known as critical success factors (CSFs) that can en sur the successful implementation of the safety programs |