anglophone and francophone population, a heavier reliance on symbols rather than text legends and metric measurements instead of imperial. The Ministry of Transportation of Ontario (MTO) also has historically used its own MUTCD which bore many similarities to the TAC MUTCDC. However, as of approximately 2000, MTO has been developing the Ontario Traffic Manual (OTM), a series of smaller volumes each covering different aspects of traffic control (e.g., regulatory signs, warning signs, sign design principles, traffic signals, etc.). Central America For road signs in Central American countries, the Central American Integration System (SICA) publishes its own , a Central American equivalent to the US MUTCD. See also Comparison of MUTCD-influenced traffic signs Comparison of traffic signs in English-speaking territories Road signs in the United States References External links National Committee on Uniform Traffic Control Devices (NCUTCD) website MUTCD History by H. Gene Hawkins