What metaphors are used in For the Sake of Strangers by Dorianne Laux?

Momentum is not speed that is controlled or guided. When it is used as a metaphor in the poem, it depicts speed acting on its own. The momentum in the speaker's life is an unknown, as the rest of the poem indicates. Whether the momentum will build and take the speaker hurtling deeper into despair or lift her out of despair and back into normalcy and contentment remains to be seen. Regardless, the speaker is not in the driver's seat.