Goal-directed navigation requires animals to continuously evaluate their current direction and speed of travel relative to landmarks to discern whether they are approaching or deviating from their goal. Striatal dopamine release signals the reward-predictive value of cues1,2, likely contributing to motivation3,4, but it is unclear how dopamine incorporates an animal’s ongoing trajectory for effective behavioral guidance. We demonstrate that cue-evoked striatal dopamine release in mice encodes bi-directional 'trajectory errors' reflecting the relationship between the speed and direction of ongoing movement relative to optimal goal trajectories. Trajectory error signals could be computed from locomotion or visual flow, and were independent from simultaneous dopamine increases reflecting learned cue value. Joint trajectory error and cue value encoding were reproduced by the RPE term in a standard reinforcement learning algorithm with mixed sensorimotor inputs. However, these two signals had distinct state space requirements, suggesting that they could arise from a common reinforcement learning algorithm with distinct neural inputs. Striatum-wide multi-fiber array measurements resolved overlapping, yet temporally and anatomically separable representations of trajectory error and cue-value, indicating how functionally distinct dopamine signals for motivation and guidance are multiplexed across striatal regions to facilitate goal-directed behavior.