Have you ever used the route search function? Most of you have probably used the route search function that comes with map applications such as Google Maps, Apple Maps, and Open Street Map at least once. This discrete mathematical problem, called the shortest path problem in informatics, is currently being tackled by a variety of companies. In most cases, this shortest path problem can be solved by an algorithm. There are three main types of algorithms for solving the shortest path problem: Dijkstra's method, Berman-Ford's method, and Warshall-Freud's method. Basically, the route search function attached to maps uses Dijkstra's method. Specifically, Google Maps uses the Dijkstra method to guide you to a route or to solve the shortest path problem. However, if you are using the route search function, have you ever felt this way? “I'm not in a hurry, and I want to get around as cheaply as possible, but the results I get are several times more expensive than my budget.” ” I want to know how to get around with fewer transfers, even if it takes a little longer.” I will explain later which specific functions are lacking in the route search functions currently in use, but the fact is that there are few map applications that have a route search function that at least meets the "demands" of readers. I wonder if this is because they are not using the algorithm (Dijkstra method) well. So, first of all, I'd like to analyze the current situation and list the problems with the existing map apps (or route search apps) that have a route search function.I have solved this problem by providing multiple ways to derive cost, but unfortunately, the creators of route planning apps, especially Google Maps, have yet to solve the shortest path problem based on price or other factors (as of 2021). Other route planners have also not yet solved the issues mentioned in the Introduction. If features like this are added to each route planner (e.g., creating multiple ways to derive cost for Google Maps), we can expect a broader range of users to use the current route planners.