A tall signal head ahead of you carries several lenses and you are far enough back that you cannot yet make out the colours — only which lens is lit. Can the position alone tell you anything?

Correct answer: A. Yes — the order is set by regulation, with red above amber above green and any arrows below those

Yes, because the order is fixed by regulation, not by the crew who installed it. HTA Regulation 626 subsection 1(2) sets out that where these indications are used "they shall be arranged vertically from the bottom as follows: right turn green arrow, right turn amber arrow, left turn green arrow, left turn amber arrow, straight through green arrow, circular green, circular amber, circular red and white vertical bar." Read that from the top down and you get the layout you actually see: the white vertical bar for transit priority at the very top where used, then circular red, circular amber, circular green, and the arrows below them. So the lit lens nearest the top of the stack is the stop indication, and any arrow is below the circular lenses. Book 12 confirms the arrangement is mandatory: "whether combined in one unit or mounted as connected sections, the relative vertical locations ... must be as specified."

Source: MTO Driver's Handbook: Ontario Traffic Manual, Book 12 — Traffic Signals (July 2024), Section 2.7 — HTA Regulation 626, Subsection 1(2), Vertical Order of Signal Indications, and Table 1