According to the PCR (para. 9) national contractors lacked experience in environment management and engaged national environment consulting firm to prepare site specific EMPs. The lapses that occurred in the initial pre-construction stage were addressed with ADB’s support and advice.
Traffic volume and travel speed increased after the highways were improved by the project. However, the number of traffic accidents, and fatalities and injuries also increased, particularly on the project section of the Greater Mekong Subregion’s Southern Economic Corridor highway. The main reasons, according to initial examinations, were speeding and turning right onto the highway from the access roads. After the DOH implemented safety improvement measures such as installing warning signs and concrete barriers on highway medians, the number of fatalities began to decrease in 2017. Nevertheless, the project experience highlights the need for a traffic safety component to be incorporated in future highway improvement projects in Thailand, the worst country in Asia in terms of traffic fatality rate. A traffic safety assessment should also be made after the completion of future highway projects. ADB highway loans should therefore be kept open for an additional 2 years after physical completion to carry out any necessary traffic safety assessments and road safety improvement works.
The EA for this project, the Department of Highways (DOH), had adequate institutional and human resource capacities to implement the civil works and manage the contracts. It would have been better if the DOH was asked to appoint one of its resident engineers to act as the project engineer with supervisory functions over all the civil works contracts. This would have allowed the construction and supervision consultant to assist the DOH mainly in tasks where it had insufficient knowledge and experience, including implementing social safeguards, monitoring compliance to environmental safeguards, and preparing progress and completion reports. Such an arrangement may be considered in future similar situations.
The project’s civil works were completed within the estimated construction periods mainly because the contract packages were rightly sized and enough time for construction was provided for each package. It helped also that the project did not need to acquire land and the resident engineers of the executing agency (EA) stayed in the contractors’ camp sites to provide implementation and management support.