Do not enter signs are regulatory signs used where traffic is prohibited from entering a restricted roadway. The signs communicate to the drivers that the traffic will be coming towards them and they must not enter the road, off-ramp, exit ramp, or crossover where this sign is posted to avert a serious risk of collision. Do not enter road traffic signs are square in shape with a horizontal white line inside a red circle.
In addition to being used on roads to control traffic, do not enter signs are also found in facilities such as workplaces, parking lots, etc., to restrict entry to certain areas for personal, operational, or data safety.
Do not enter signs are common traffic control devices often seen at the beginning of one-way streets and ramps to restrict vehicle entry. Additionally, these signs are also used to mark dangerous areas like construction zones and facilities such as hospitals, testing centers, laboratories, data centers, offices, etc.
Do not enter signs are meant to keep people safe and help them avoid potential hazards. Ignoring a do not enter sign can prove to be rather dangerous not only for the violator but also for other people. Where not obeying these signs on the road can result in collisions, entering restricted areas in facilities can expose one to harmful situations or sensitive and confidential information. It may at times attract legal action against the violator.
Do not enter traffic signs are covered in MUTCD Section 2B.37. As stated in the section, these signs should be mounted on the right-hand side of a roadway such that it faces the traffic that might enter the roadway or ramp in the wrong direction.
These signs should be visible to road users who might wrongly enter a roadway, but where it would be visible to traffic to which it does not apply, it should be shielded or turned away from the view of such traffic.
Additionally, a do not enter sign may be used on the left-hand sign of a road where traffic approaches from an intersecting roadway.
As stated under Section 2B.37 of the MUTCD, do not enter signs are to be used on restricted roadways that traffic is prohibited from entering. Illustrated in Figure 2B-11, the do not enter sign (R5-1) should be a square white sign with a solid red disc in the middle. The disc should contain the words "DO NOT" and "ENTER" in white, above and below, respectively, a thick horizontal white line. Specifications regarding these signs’ size can be found in Table 2B-1 and cover single lane and multi-lane conventional roads, expressways, freeways, and the requirements specific to oversized do not enter signs.
Wrong way signs cannot replace but may be used to supplement do not enter signs, “where an exit ramp intersects a crossroad or a crossroad intersects a one-way roadway in a manner that does not physically discourage or prevent wrong-way entry”, as stated in the MUTCD. Wrong-way and do not enter signs are often used together to drivers that they are headed in the wrong direction.