Motorcycle
A motorcycle carries you fast with your body exposed, so it stands for speed and precariousness together. Riding smoothly is a good omen of things moving quickly, and also reads as going forward under your own power. Wobbling or falling, by contrast, signals a call to slow down, and riding behind someone means being carried at a speed another person set. It does not forecast a real accident, but if your schedule is punishing, look at that too.
A motorcycle falls over when it stops and finds its balance only while moving. Tradition had no such symbol, but the sense is plain. How you rode decides the meaning.
Readings by Situation
Riding smoothly
A good omen of things moving quickly. It also reads as going forward under your own power. A good wind on your face reads more strongly still.
Wobbling or falling
A signal to slow down. Read it as balance not holding. Less a forecast of failure than a call to look at whether your schedule is too heavy.
Riding behind someone
The pace is being set by someone other than you. If it felt easy, this is a fine time to let others carry it; if it made you uneasy, take the controls back. If you remember whose back you were behind, look at where you stand in that relationship too.
The bike stopping or breaking down
A sign that the force pushing you has run out. Read through the old symbols of vehicles, it is time to rest. It also comes up often when your body is tired.
A motorcycle dream does not forecast a real accident. It is a scene drawn by what sits between speed and risk. Still, if your schedule is genuinely punishing, look at that too.