It sounds a bit redundant at first — you’re already in a designated turning lane, yet you must use your turning signal. However, in states like California, you may get a ticket if you don’t. 

According to the California DMV’s Driver’s Handbook, there are certain steps drivers must take before taking a left or right turn. This includes entering a designated turn lane if one is available, looking out for pedestrians and bicyclists, and then turning on a turn signal about 100 feet ahead of the turn itself, usually before stopping behind the limit line. 

While it’s not explicitly stated, this section of the Driver’s Handbook indicates that you’ll need to use the turn signal even if there’s a designated turning lane. This is emphasized in California Code, VEH 22108, which states: “Any signal of intention to turn right or left shall be given continuously during the last 100 feet traveled by the vehicle before turning.” No exceptions are mentioned. 

California isn’t alone in requiring a turn signal when you’re in a designated turning lane. It’s a pretty general traffic safety law throughout the United States. 

Florida Statute 316.155 requires drivers to use a turn signal any time they turn a vehicle, turning it on 100 feet before the turn. Massachusetts General Laws Chapter 90, Section 14B also requires drivers to use a turn signal “before making any turning movement.” Nebraska Statute 60-6,161 also states that drivers must use a turning signal 100 feet ahead of any turn. 

While it may seem redundant or obvious to the driver, this law exists to keep drivers safe. A turn lane won’t necessarily tell other drivers your thoughts — although it can be assumed. The turn signal itself shows your actual thought process and intentions more clearly. It’s all about communication — to other drivers, to pedestrians, and everyone else around you. 

You will also avoid fines: it’s $238 if you violate California Code 22108 — though some would argue not to pay it. It’s best to just follow the general turn signal rules, whether it’s a designated turning lane or a roundabout.