When the prefectural public safety commission (hereinafter referred to as a "public safety commission") finds it necessary in order to prevent hazards on roads and otherwise ensure the safety and fluidity of traffic, or to prevent traffic nuisances and other harm arising from road traffic, it may, pursuant to Cabinet Order, install and manage traffic lights or road signs or markings and thereby carry out traffic control, prohibit the passage of pedestrians or remotely operated small vehicles (limited to those traveling on a road by remote operation) (referred to as "pedestrians, etc." in the following Article through Article 13-2) or of vehicles or streetcars, or otherwise regulate traffic on roads. In this case, if it is urgent and there is no time to install road signs or markings, or it otherwise finds it difficult to regulate traffic with road signs or markings, the public safety commission may, through on-site instructions given by a police officer of the prefectural police under its management, regulate traffic in a manner equivalent to regulating traffic by installing and managing road signs or markings.
都道府県公安委員会（以下「公安委員会」という。）は、道路における危険を防止し、その他交通の安全と円滑を図り、又は交通公害その他の道路の交通に起因する障害を防止するため必要があると認めるときは、政令で定めるところにより、信号機又は道路標識等を設置し、及び管理して、交通整理、歩行者若しくは遠隔操作型小型車（遠隔操作により道路を通行しているものに限る。）（次条から第十三条の二までにおいて「歩行者等」という。）又は車両等の通行の禁止その他の道路における交通の規制をすることができる。この場合において、緊急を要するため道路標識等を設置するいとまがないとき、その他道路標識等による交通の規制をすることが困難であると認めるときは、公安委員会は、その管理に属する都道府県警察の警察官の現場における指示により、道路標識等の設置及び管理による交通の規制に相当する交通の規制をすることができる。
The regulation of traffic under the preceding paragraph is undertaken at a specific location or within a specific area or section of a road. It may have a limited target and its application may be limited to certain days or hours.
A public safety commission must endeavor to install traffic lights at high-traffic intersections other than roundabouts (meaning intersections with a circular area for motor vehicle traffic, where drivers of vehicles are directed by road signs or markings to proceed in a clockwise direction; the same applies hereinafter), and at other locations where lights are found to be necessary to prevent traffic hazards.
Cabinet Order provides for the meanings of signals displayed by traffic lights and for other necessary particulars concerning traffic lights.
信号機の表示する信号の意味その他信号機について必要な事項は、政令で定める。
Cabinet Office Order/ Order of the Ministry of Land, Infrastructure, Transport and Tourism provides for the types, formats, placement, and other necessary particulars concerning road signs and markings.
道路標識等の種類、様式、設置場所その他道路標識等について必要な事項は、内閣府令・国土交通省令で定める。