Understanding how the brain guides us toward goals while avoiding distractions has profound implications for treating movement disorders, addiction, and age-related cognitive decline. The dopamine system, long viewed primarily as a reward processor, appears to operate a sophisticated dual-channel navigation system that could inform therapeutic approaches for conditions affecting motor control and decision-making. New research using advanced multifiber recording techniques in navigating mice reveals that striatal dopamine neurons simultaneously encode two distinct types of information: trajectory errors that signal how far an animal deviates from optimal paths, and traditional reward-predictive value signals. These trajectory error signals operate bidirectionally, increasing when animals move away from goals and decreasing when approaching them, computed from either locomotor feedback or visual flow patterns. Crucially, this navigation guidance system functions independently from the well-established reward value encoding, suggesting dopamine operates parallel processing channels rather than a single reward-focused stream. The findings align with reinforcement learning models that incorporate mixed sensorimotor inputs, but the distinct neural requirements suggest separate input pathways converging on dopamine circuits. Multifiber recordings across striatal regions revealed these signals overlap spatially but maintain temporal and anatomical separation, indicating sophisticated multiplexing within dopamine networks. This dual-function dopamine system represents a significant conceptual advance beyond traditional reward-centric models. For aging adults, these findings suggest that maintaining dopamine system integrity involves preserving both motivational and navigational functions. The discovery could explain why dopamine-related disorders like Parkinson's disease affect both movement precision and reward processing, potentially guiding more targeted therapeutic interventions that address both navigational accuracy and motivational drive in age-related cognitive decline.