Risk and Uncertainty in the Cost Contingency of Transport Projects: Accommodating Bias or Heuristics, or Both?

Transport projects are regularly subjected to cost misperformance. The contingency set aside cover any increases in due risk and uncertainty issues is often insufficient. We review approaches that have been used estimate a contingency. show some such as reference class forecasting, which underpins the planning fallacy theory, take biased view formulate Indeed, there perception risks uncertainties form parts of cannot be accurately assessed using heuristics. absence an overarching theory support use heuristics has resulted them being downplayed project's investment decision-making process. This article fills this void provides theoretical backdrop make clarion call reconcile duality bias heuristic approaches, propose balanced framework for developing contingency, suggest uplifts derisk estimates redundant. hope our advocacy approach will stimulate debate question legitimacy solely debias estimates.