Conn. Gen. Stat. § 14-248a

The Commissioner of Transportation, or the local traffic authority on highways under its jurisdiction, shall control the placing of cattle crossing signs within the limits of the traveled portion of the roadway of any public highway. No such cattle crossing sign shall be so placed without the securing of a permit from said commissioner or such traffic authority, as the case may be, which permit shall specify the size, color, wording and placement of such signs. Cattle crossing signs shall be so placed only when animals are actually crossing or are about to cross the roadway. When such signs are in position, the operator of any vehicle shall appropriately reduce speed or stop if necessary to avoid endangering or striking any animal crossing the roadway. Failure to reduce speed or stop in accordance with the provisions of this section shall be an infraction.