Do not block intersection sign: what it means
The DO NOT BLOCK INTERSECTION sign means you must not enter the intersection unless there is room to get all the way across.
What does the DO NOT BLOCK INTERSECTION sign mean?
MUTCD Section 2B.59 lists DO NOT BLOCK INTERSECTION (R10-7) among the traffic signal signs, used to avoid traffic obstructions.
Quick quiz
What does the sign at the top of this page mean?
- Traffic lights are ahead.
- Do not stop inside the intersection.
- Stop at this line when the light is red.
Show answer
B. Do not stop inside the intersection. It is used to keep traffic from blocking the intersection (MUTCD Section 2B.59). Source: MUTCD 11th Edition, Chapter 2B, Regulatory Signs, Barricades, and Gates: Section 2B.59, FHWA; MUTCD 11th Edition, FHWA
Where will you see it?
At busy signalized intersections where traffic backs up.
What should you do?
Before you enter on green, check there is space on the far side for your whole vehicle. If not, wait.
What do people get wrong?
Entering on a green light behind stopped traffic and getting stuck when the light turns red.
Common questions
Can I enter on a green light if traffic is backed up?
Not if you would be left stopped in the intersection. Wait until there is room on the other side.
Are there markings too?
Some cities add pavement markings. The rule on the sign applies either way.
Compare with
Signal ahead signTraffic lights are ahead.
Stop here on red signStop at this line when the light is red.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 4 November 2026 against the MUTCD 11th Edition (FHWA), Section 2B.59.
- MUTCD 11th Edition, Chapter 2B, Regulatory Signs, Barricades, and Gates: Section 2B.59, FHWA
- MUTCD 11th Edition, FHWA. FHWA lists the current version as the 11th Edition with Revision 1, dated December 2025
Sign pictures are our own simplified drawings of the MUTCD designs, which are in the public domain (MUTCD Section 1D.06). Sources and image credits.