High Quality Content by WIKIPEDIA articles! The 400- series highways are a network of controlled- access freeways throughout the southern portion of the province of Ontario, Canada, forming a special subset of the provincial highway system. They function similarly to the Interstate Highway network in the United States. Modern 400-series highways have high design standards, speed limits of 100 kilometres per hour (62 mph), and various collision avoidance and traffic management systems. 400-series highway design has set the precedent for a number of innovations used throughout North America, including the parclo interchange.