The Meaning Of NORAC Signals

Quick Reference Guide

Version 0.2 (6/08) -- Copyright © 2008 Deltareum. All rights reserved.

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First, A Few Terms: Signal Aspects, Names And Indications

The following are simplified definitions of signal terms, but not the actual NORAC definitions.

Signal aspect is the way a signal looks.
Signal name is what the signal is called.
Signal indication is what the signals indicate to us to do.

Signal Types

Again, the meanings of signals are explained in plain language. They are not the actual indications.

There are basically three types of signals:

1. Signals That Bring You To A Stop.

2. Signals That Regulate Your Speed

First come the Clears:

Signals that bring your speed down:

In basic terms the following math equations are true:

Medium Approach ≅ Medium Clear + Approach.
Slow Approach ≅ Slow Clear + Approach.
Medium Approach Medium ≅ Medium Clear + Approach Medium.

The symbol “≅” means "approximately equal," as the indications do not match exactly.

3. Oddball Signals

On our territory, you may also see this one:

This concludes the discussion on the meaning of signals. Signal Progressions explains how signals are used with each other.