Q 01/05

In which US city did police sergeant Harry Jackson create the first stop sign in 1914?

A) Detroit

B) Chicago

C) Cleveland

D) Pittsburgh

Answer · why

A) Detroit

He cut the corners off a piece of plywood, wrote STOP on it and faced it at a blind street; Michigan adopted the idea statewide the next year.

Q 02/05

Why did a 1922 US committee pick the octagon for stop signs?

A) It was cheapest to stamp

B) Drivers could recognise it from behind

C) It echoed railway semaphores

D) Eight sides for eight states

Answer · why

B) Drivers could recognise it from behind

A driver seeing the back of the sign knows oncoming traffic must stop. The shape also stood out at night, since early signs were not reflective.

Q 03/05

What background colour did US stop signs have from 1924 to 1954?

A) White

B) Green

C) Yellow

D) Blue

Answer · why

C) Yellow

Fade-resistant red materials did not exist yet. The red-field, white-legend sign was specified in 1954 to match red traffic lights.

Q 04/05

In which year did the MUTCD first specify a white STOP legend on a red field?

A) 1958

B) 1966

C) 1954

D) 1971

Answer · why

C) 1954

The same edition raised the rural mounting height to 5 feet; the current 7-foot height dates from 1971.

Q 05/05

What shape is Japan's stop sign?

A) An inverted red triangle

B) A red octagon

C) A red circle

D) A white diamond

Answer · why

A) An inverted red triangle

South Korea, Hong Kong and Taiwan use the standard octagon. Zambia and Zimbabwe used a disc with a black cross until 2016.