Weather forecast plays an important role in the strategic air traffic flow management decision. In our previous study, we modeled the single-aircraft routing decision problem as a Geometric Recourse Model (GRM) when the preferred route is unavailable due to a weather disruption in the airspace. The stochastic optimization model generates an optimal route to achieve the minimum expected total cost while reducing the weather related risks. In this paper, we adopt the same geometric setup and employ the decision analysis framework to assess the value of perfect weather information in strategic routing decision problem. The binomial route choice theorem states that the optimal route is either the nominal or the detour route once the weather clearance time is given. The theorem also identifies time threshold that determines the optimal choice between the two route options. We obtain the value of perfect information over a large set of weather parameters by solving both the stochastic GRM and the GRM with known clearance
time. Numerical analysis suggests that improvement with perfect weather information is marginal overall, except for a small set of parameter combinations that generates cost saving close to 10%. The study validates the importance of incorporating the probabilistic nature of the weather uncertainty into strategic traffic flow management decision, as it is as important as improving the accuracy of the weather information itself. Index Terms—value of perfect information; PATM; geometric recourse model; geometric model