# 49. Manipulation of bias and heuristics in decision making ## 49.5. Methodology/Refinements/Sub-species ### 49.5.71. Well-travelled road effect This is both the underestimation of the time taken to traverse oft-traveled routes, and the overestimation of the time needed to traverse less familiar routes. A manipulator can use this flaw in estimation to trick a victim into making poor approximations of the time required to reach a particular destination. A "route" can also be seen as a synonym for a process, like a project plan, or a development plan, etc. A familiar activity will be underestimated, whilst an unfamiliar activity will be overestimated in terms of effort, time and resources required.