A Road Narrows Left sign is a warning sign. A Road narrows Left sign indicates that road users will have less space on the left-hand side for manoeuvring in their lane. A road narrows left sign prepares road users for driving closer to other road users and embankments, signalling that they should reduce their speed to have maximum control over the vehicle. A road narrows left sign can be used in conjunction with other road signs, common usage includes on roads that lead to old, small bridges where the road is narrow and cannot be made wider.