In Electronic Orientation Aids, the guidance process consists in two steps: first, identify the location of a visually impaired user along the expected trajectory, and second, provide her/him with appropriate instructions on directions to follow, and pertinent information about the surroundings. In urban environment, positioning accuracy is not always optimal and tracking the user's progress along the expected itinerary is often challenging. We present three new waypoint-based validation strategies to track the user's location despite low positioning accuracy. These strategies are evaluated within SIMU4NAV, a multimodal virtual environment subserving the design of Electronic Orientation Aids for visually impaired people. Results show that the proposed strategies are more robust to positioning inaccuracies, and hence more efficient to guide users.