No U-Turn Signs
MUTCD R3-4

No U-Turn Signs communicate to drivers that U-turns are not allowed at a given intersection, typically at an intersection with traffic lights. The No U-Turn Symbol Sign (R3-4) features an arrow symbol curved to the left in an upside-down U-shape, overlaid with a red circle and diagonal line. A variation of the R3-4 is the No U-Turn Or Left Turn Symbol Sign (R3-18). The R3-18 layers a left-turn arrow over a U-turn arrow, and this modified symbol is also overlaid with a red circle and diagonal line.

Like other “Turn Prohibited” Signs, No U-Turn Signs restrict vehicle movement to maintain safe traffic flow. In contrast, the Left Turn and U-Turn Symbol Sign (R3-6A) is optionally used at intersections where both a left turn and U-turn are allowed (2B.27, 02).

Because at certain intersections, allowing drivers to U-turn creates an unpredictable and dangerous “conflict of movement”.

For example, when traffic lights are “green” on both northbound and southbound multi-lane roads, each side of the road may allow a “Left Turn on Yield”. A northbound vehicle may enter the left turn lane, check for southbound traffic, and attempt a U-turn. Although the driver may have intended to enter the leftmost lane, if median is too narrow or the curve of the turn is too sharp, the vehicle may unintentionally enter the center lane.

In this scenario, U-turns will likely endanger all drivers that pass through the intersection. Using a No U-Turn Sign would be an essential tool in keeping drivers safe.

When a R3-18 sign is used, both U-turns and left turns are prohibited. The sign informs drivers that they can either continue straight or, in most cases, can also make a right turn.

For example, a “No U-Turn or Left Turn” Symbol Sign can be placed when a two-lane main road intersects with a one-way only road. There are two movement restrictions in this case. When traffic on the one-way road flows to the right, that prevents drivers from making a left turn. When incoming traffic or intersection geometry interferes with a U-turn, it cannot be safely performed.

For both “No U-Turn” and “No U-Turn Or Left Turn” Symbol Signs, single lane roads require 24”x24” signs, while multi-lane roads and highways require 36”x36” signs. For overhead mounting, signs should be 48”x48”.

No U-Turn Signs can be mounted in one of three configurations: overhead only, post-mounted only, or both overhead and post-mounted (2B.26, 12). The MUTCD notes that post-mounted signs can be placed at the far left of the intersection, on a median, or with a Stop Sign or Yield Sign on the near right corner (2B.26, 05, 07).

For overhead mounting, check out our Overhead Sign Brackets page. To post-mount signs, use a round, square, or U-channel post with our Sign Installation Hardware.

080” rustproof aluminum provides the base for our No U-Turn Signs. Your choice of white high-intensity prismatic (HIP) sheeting or white full-cube prismatic (FCP) sheeting will be securely adhered onto the aluminum. HIP sheeting has a 10-year warranty, while FCP sheeting has a 12-year warranty.

No U-Turn Signs are shipped in cut-to-size cardboard and stacked back-to-back. We layer slip sheeting onto each sign face to protect signs during shipment.

We ship most orders the same or next day. We offer free shipping on traffic signs and stands. UPS tracking numbers are emailed to the customer when the items are picked up by the shipping carriers.

Section 2, Chapter 2B of the MUTCD contains more information about these signs.