Q 01/05

Where was the world's first traffic signal, a gas-lit semaphore, erected in December 1868?

A) London

B) Paris

C) New York

D) Berlin

Answer · why

A) London

It stood outside the Houses of Parliament near Westminster Bridge and was operated by a policeman.

Q 02/05

What fate befell the 1868 Westminster gas signal only weeks after it was switched on?

A) It was stolen

B) It exploded

C) A carriage flattened it

D) A storm toppled it

Answer · why

B) It exploded

A gas leak set it off and badly injured the policeman working it; Britain did without traffic lights again until 1929.

Q 03/05

In which city did the American Traffic Signal Company install an electric traffic light at Euclid Avenue in August 1914?

A) Chicago

B) Pittsburgh

C) Cleveland

D) Buffalo

Answer · why

C) Cleveland

It had red and green lights and a buzzer, and was wired so that conflicting signals could not show at once.

Q 04/05

Which inventor patented a manually operated three-way traffic signal with moving arms in 1923?

A) Elmer Sperry

B) Lewis Latimer

C) Granville Woods

D) Garrett Morgan

Answer · why

D) Garrett Morgan

Morgan, also known for an early gas mask, reportedly sold the rights to General Electric.

Q 05/05

Which country decreed in 1973 that the 'go' light should be the bluest possible shade of green?

A) Japan

B) South Korea

C) Thailand

D) China

Answer · why

A) Japan

The word for the light there was traditionally the same word used for blue, so the tint was changed to match the name.