Abstract:
Various attempts have been taken in order to achieve the objective of environmental soundness in road
construction activities. Effectiveness of allocating the funds and the due payment for the contractor
can create a great influence in achieving such an objective. Thus, this study aims to identify what is the
optimum payment evaluation method of contractor’s due payment for controlling environmental
defilement in road construction projects. The aforesaid research problem was approached through a
multiple case study including three road construction projects in Sri Lanka. Different environmental
hazards occurred due to different road construction activities, related hazard mitigation methods, fund
allocation for environmental hazard controlling and the associated existing payment methods for
contractors could be identified through the data collected by means of semi-structured interviews
conducted with the professionals who are involved in the projects having knowledge on both
environmental and monetary aspects. Further, direct observations and documentary survey
strengthened these findings. Quantitative data was collected from each case through a questionnaire
survey and prioritized the payment method under each specific hazard controlling method using
Relative Importance Index in terms of effectiveness to identify the optimum payment method to the
contractor for controlling environmental hazard. Findings revealed that there are four types of such
payment methods available including; payments by unit rate, payments where a provisional sum
established in the contract; payments where fixed amounts are assigned in the contract and payments
made along with some main work item in the contract which were identified being the optimum method
under different hazard controlling methods. These findings would be useful for bidders and estimators
at the pre-construction stages to develop more effective modes of payment evaluation and to improve
effectiveness in estimation.
