Abstract
A 30 km/h speed limit will apply to traffic on the roads without center lines, multiple lanes, etc.in residential areas from September 2026 which under a revision to the Order for Enforcement of the Road Traffic Law, approved at a Cabinet meeting on July 23. In the pre-enforcement phase, the development and establishment of efficient and effective nationwide uniform road traffic condition and usage monitoring methods and the assurance of their effectiveness are policy issues, while the implementation of practical monitoring is an urgent issue after enforcement. This study focuses on car probe data, a kind of passive data, and aims to organize policy issues by proposing a practical monitoring method and case studies of road traffic when the 30 km/h regulation is enforced on residential roads. Considering the ease of handling by the management entity of residential roads, we propose a method that allows regular monitoring at the municipal level and evaluation of traffic conditions over multiple periods of time by elementary school. As monitoring indices, we developed indices related to the areas adjacent to the roads, such as the number of sudden deceleration and the number of vehicles traveling at less than 30 km/h on the roads, taking advantage of the characteristics of the car probe data. Through a case study in Gifu City, we could identify there was value differences between two periods by elementary school district and mesh. As a result, we could clarify that practical monitoring of the 30 km/h regulation on residential roads is possible by using car probe data, which is a nationally uniform standard and passive data. In addition, we could extract policy issues from the viewpoints of use data, monitoring indicators, management system, and monitoring for the future.
