Traffic congestion is an unpreventable problem to avoid in a transportation network and it has negative effects on traffic accident, time wasting, traffic delay and safety problem. Besides, in transportation networks, drivers do not want to deal with traffic jam while traversing between specified origin-destination pair. Therefore, traffic assignment (TA) is imperative to improve traffic management, transportation safety, time, and cost savings. System Optimum Traffic Assignment Problem (SOTAP) is a kind of TA model which aims to minimize the total system travel time on the network, and satisfies the flow conservation constraints. To model the SOTAP more realistically, the imprecise parameters can be taken as fuzzy. Therefore, in this paper, we focus on converting the conventional SOTAP to a fuzzy quadratic programming problem (QPP) which is named System Optimum Fuzzy Traffic Assignment Problem (SOFTAP). Here, link travel time is expressed with BPR function as generally used in the literature by converting to fuzzy except link-dependent parameters. Thus, the nonlinear objective function of SOFTAP is expressed in terms of fuzzy link flows and fuzzy link travel times. A solution approach from the literature is modified to the reconstructed SOFTAP.

交通拥堵是交通网络中不可预防的问题，它对交通事故、时间浪费、交通延误和安全问题产生负面影响。此外，在交通网络中，司机在指定的起点-终点对之间穿梭时不想处理交通拥堵。因此，交通分配（TA）对于改善交通管理、交通安全、时间和成本节约势在必行。系统最优流量分配问题（SOTAP）是一种以最小化系统在网络上的总行程时间为目标，满足流量守恒约束的TA模型。为了更真实地对 SOTAP 建模，可以将不精确的参数视为模糊。因此，在本文中，我们专注于将传统的 SOTAP 转换为模糊二次规划问题 (QPP)，称为系统优化模糊交通分配问题 (SOFTAP)。在这里，链接旅行时间用文献中通常使用的 BPR 函数表示，通过转换为模糊，除了链接相关参数。因此，SOFTAP 的非线性目标函数用模糊链接流和模糊链接旅行时间来表示。将文献中的解决方法修改为重构的 SOFTAP。