In Connecticut the maximum speed limit of 65 mph (105 km/h) is usually posted on rural freeways, up to 55 mph (89 km/h) is posted on rural divided and undivided highways. In urban areas speed limits vary from 25 mph (40 km/h) on residential streets and central business districts to 30–40 mph (48-64 km/h) on arterial roadways, and from 45 to 55 mph (72 to 89 km/h) on urban freeways. Limited-access divided highways have a minimum speed of 40 mph (64 km/h), but this is not always posted, and rarely enforced.
Speed limits for all roads within Connecticut, including local streets, are established by the State Traffic Commission, an agency composed of members of the Department of Motor Vehicles (CTDMV), the Department of Emergency Services and Public Protection (DESPP), and the Department of Transportation (CONNDOT).
The State Traffic Commission typically sets speed limits following engineering studies performed by CONNDOT. Data used in setting speed limits includes: traffic volume vs. roadway capacity, design speed, road geometry, spacing of intersections and/or interchanges, number of driveways and curb cuts, and accident rates.
Municipalities are normally required to seek approval from the State Traffic Commission for changes to the posted speed limits on locally owned streets after appropriate engineering studies are performed.
Speeding fines are doubled in school zones when children are present, and construction areas when workers are present.