The research is aimed to 1) study the level and priority of the factors affecting the delay of construction projects and 2) provide suggestions in relation to the prevention of such delay. The sample is 520 people who were working for different construction projects. They were project managers project engineers field engineers and foremen. The data were collected by using online questionnaires and analyzed to find out mean standard deviation (SD) frequency correlation coefficient and confirmatory factor analysis. The findings reveal two significant aspects. First those who were working in the construction projects concerned about the factors affecting the delay of the projects at high level. Respectively the factors related to design resource external factors and others were taken into consideration. The factor regarding to work performance is regarded affecting the project delay at the highest level. Other factors i.e. the design external factors and others and resource have the affects at the lower level. Second the work-related factors can help prevent the project delay. In other words the construction plan and methods as well as the project management should be well-implemented in accordance with the design. The construction site should be on inspection considering its drawing. Regarding the external factors and others the public voices of those living around the construction site should be taken into consideration. Furthermore the effective use of the resources can be carried out by sufficiently preparing all materials tools and equipment for constructing any project effectively as a consequence.

This research aims to evaluate the effectiveness and limitations of the Road Safety Audit in Thailand. The evaluations would be used as a guideline to set Road Safety Audit policy for transport authorities in order to enhance the traffic safety in the construction area. In the study the construction project route 318 Trat-Had Lek part2 (Section1) Sta.1+900.00 to 20+000.00 (total distance of 18.100 kilometer) was selected as a case study. The accident statistics occurred before the construction and during the construction were compared to analyze the effectiveness of the Road Safety Audit used in the project. The result of the study shows that the main cause of the accident are traffic management traffic sign and marking as well as pavement surface. Therefore the researchers have provided some recommendations against the accident causes. Finally the operations of the contractors according to the recommendations were monthly summarized to measure the effectiveness of the recommendations.