Sign shapes and colorsQuestion 3 of 223

Which sign has a circle as its shape?

  1. Advance warning of a school
  2. Advance warning of a railroad crossing
  3. Advance warning of a curve
  4. Advance warning of a stop
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Correct answer: Advance warning of a railroad crossing

A circle is the shape of the railroad advance warning sign. No other sign uses a circle for this purpose.

Source: Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD), 11th Edition with Revision 1 (FHWA, December 2025), Section 2A.05 Shapes, page 83

Practice sign shapes and colors

Questions last reviewed: 18 October 2026