Freeway Weaving: Comparison of Highway Capacity Manual 2000 and Dutch Guidelines

Weaving sections are a commonly adopted freeway facility both in the United States and in Europe. Knowledge about the capacity and level of service achievable on different types of weaving segments is necessary for the design and management of freeways. Guidelines such as those of the U.S. Highway Capacity Manual (HCM) provide capacity values for different weaving configuration types. The Dutch guidelines for the design of weaving segments are compared with those of the U.S. HCM. Differences between their respective approaches are identified, and a comparison of capacity values is conducted. It was found that there are large differences in capacity estimates for certain weaving configuration types. The results of a sensitivity analysis explain these differences in capacity values to a large extent. This analysis showed that it is important to consider the weaving proportions per leg. Currently, neither the HCM nor the Dutch approach considers different weaving flows per incoming leg. The introduction of an additional variable into the calculation procedure that takes into account the presence of asymmetrical weaving flows is recommended.