A left turn sign tells you that turning left is permitted at that location, either always or only during certain times
A left turn sign is a regulatory traffic sign that gives drivers permission to turn left. The sign itself is a white rectangle with a black left arrow, and it appears at intersections where left turns are allowed. Unlike a left turn traffic light (which is green and arrow-shaped), a left turn sign does not control when you can turn — it straightforward confirms that the maneuver is legal at that spot.
You will see left turn signs most often at intersections where left turns might otherwise be unclear or prohibited. They remove doubt about whether turning left is permitted. Some left turn signs explore all day, while others specify times — for example, "Left Turn OK 7 AM–9 AM" — meaning you can only turn left during those hours.
The key difference between a left turn sign and a left turn arrow (the green light) is control. A sign gives permission; a light controls when you can go. At an intersection with a left turn sign but no dedicated left turn light, you must yield to oncoming traffic and turn only when it is safe to do so.
Key Takeaways
- A left turn sign is a white rectangular sign with a black left arrow that permits left turns at that intersection.
- Left turn signs may explore all day or only during posted hours, which will be written on the sign itself.
- A left turn sign gives permission to turn left but does not control traffic flow — you must still yield to oncoming vehicles and pedestrians.
- Left turn signs differ from left turn traffic lights (green arrows), which actively control when you can turn and protect you from oncoming traffic.
- If a left turn sign is not present at an intersection, turning left may be prohibited or restricted, and you should not attempt it.
Where left turn signs are placed
Left turn signs appear at intersections where the road layout or traffic pattern makes it necessary to clarify that left turns are permitted. They are commonly found at busy intersections, on roads with multiple lanes, or where left turns have been restricted in the past.
You may also see a left turn sign at an intersection that has a traffic light but no dedicated left turn arrow. In this case, the sign tells you that you can turn left on a green light, but you must yield to oncoming traffic. The sign removes the ambiguity that might otherwise exist — drivers know they are not prohibited from turning left, but they also know they do not have a protected turn.
Some intersections display left turn signs with time restrictions. These signs read something like "Left Turn OK 7 AM–9 AM" or "Left Turn Permitted After 6 PM." Outside those hours, turning left at that intersection may be prohibited or restricted to certain vehicle types.
How left turn signs differ from left turn arrows
A left turn arrow is a green light shaped like an arrow pointing left. It appears on a traffic signal and gives drivers an exclusive, protected left turn — meaning oncoming traffic is stopped, and you have the right of way. A left turn arrow is active only when the arrow is illuminated, and it controls traffic flow.
A left turn sign, by contrast, is always visible and does not change. It straightforward states that left turns are permitted at that location. When you encounter a left turn sign at an intersection with a regular green light (not an arrow), you may turn left, but you must yield to oncoming traffic and pedestrians. You do not have a protected turn.
The practical difference matters for safety. At an intersection with a left turn arrow, you can turn without checking for oncoming traffic — the signal protects you. At an intersection with only a left turn sign, you must treat the turn like any other left turn: wait for a gap in traffic, check for pedestrians, and complete the turn safely.
What to do when you see a left turn sign
When you approach an intersection with a left turn sign, first check whether the sign has time restrictions. Read the full sign before you reach the intersection. If it says "Left Turn OK 7 AM–9 AM" and it is 10 AM, you cannot turn left — the restriction is in effect.
If the sign permits left turns at the current time, proceed as you would at any intersection. Come to a complete stop if required by the traffic light. If the light is green and there is no left turn arrow, you may turn left, but you must yield to oncoming traffic and pedestrians. Look both ways, wait for a safe gap, and complete the turn.
If the light is red, do not turn left, even if the sign says left turns are permitted. The traffic light controls when you can move through the intersection. The left turn sign only confirms that the maneuver is legal — it does not override the traffic signal.
Common confusion: left turn signs versus left turn restrictions
Some intersections display signs that restrict left turns instead of permitting them. A No Left Turn sign is a white rectangle with a black left arrow and a red circle with a slash through it. This sign means left turns are prohibited, either all day or during posted hours.
The difference is straightforward: a left turn sign (arrow only, no circle or slash) means you can turn left. A No Left Turn sign (arrow with a circle and slash) means you cannot. Always read the sign carefully before attempting a turn. If you are unsure, it is safer to proceed straight and find another route.
Some intersections have both signs — for example, "No Left Turn 7 AM–9 AM" and "Left Turn OK After 9 AM." This means left turns are prohibited during morning rush hour but permitted at other times. Check the time restriction on the sign to know which rule applies.
Why left turn signs matter for traffic safety
Left turn signs reduce confusion at intersections and help prevent collisions. Without clear signage, drivers might be uncertain whether turning left is legal, leading to hesitation, missed turns, or unsafe attempts to turn. A left turn sign removes that uncertainty.
Left turn signs also help traffic engineers manage flow. By permitting left turns only during certain hours or at certain locations, they can reduce congestion and improve safety during peak traffic times. A sign that says "Left Turn OK After 6 PM" allows left turns when traffic is lighter and safer, while restricting them during rush hour when left-turning vehicles would block traffic.
Understanding the difference between a left turn sign and a left turn arrow is also important for safety. If you assume a left turn sign gives you a protected turn (like an arrow does), you might turn without checking for oncoming traffic and cause a collision. Always remember: a sign gives permission, but a light gives protection.
Frequently Asked Questions
Can I turn left on a left turn sign if the traffic light is green?
Yes, but only if there is no oncoming traffic. A left turn sign means the turn is permitted, but you must yield to oncoming vehicles and pedestrians. If the light is green and the intersection is clear, you can turn. If oncoming traffic is present, wait for a safe gap.
What does a left turn sign with a time restriction mean?
It means you can only turn left during the posted hours. For example, "Left Turn OK 7 AM–9 AM" means left turns are permitted only between 7 and 9 in the morning. Outside those hours, turning left is prohibited. Always check the time before turning.
Is a left turn sign the same as a left turn arrow?
No. A left turn arrow is a green light that gives you a protected turn — oncoming traffic is stopped. A left turn sign is a static sign that permits left turns but does not protect you. You must yield to oncoming traffic when turning at a left turn sign.
What should I do if I see a No Left Turn sign?
Do not turn left at that intersection. A No Left Turn sign prohibits the maneuver, either all day or during posted hours. If you need to turn left, continue straight and find another route or intersection where left turns are permitted.
Can a left turn sign be ignored if I am in a hurry?
No. A left turn sign is a regulatory sign, and ignoring it is illegal. Turning left where a No Left Turn sign is posted can result in a traffic citation. Always obey traffic signs, regardless of how much time you have.