Friday, January 27, 2006

Traffic lights and signs

Almost everything you'd ever want to know about traffic signals and signs can be found in the Manual on Uniform Traffic Control Devices (MUTCD) from the Federal Highway Administration. MUTCD defines the standards used nationwide to install and maintain the signs, signals, and pavement markings on all streets and highways. Everything else you'd want to know is probably in Massachusetts Construction and Traffic Standard Details from the Mass. Highway Department. This 197-page document references the MUTCD, but goes on to provide the smallest details of highway construction and traffic signage in Massachusetts. For example, the section on Standard State Route Marker provides "Use M8 dia. hot dipped galvanized button head bolt with a slot in head and nut with lockwasher, with a minimum of 6 mm of threads beyond nuts on all signs after they are securely fastened." These documents and more are linked from Law About Traffic Violations.