Abstract: A network system determines and remediates dissimilarities between a digital map and trace data of a road network in an area as service providers and service requesters coordinate service using the road network in the area. To determine dissimilarities the network system can select and convert a digital map, aggregate received trace data into trace data accurately representing the road network in the area, generate a visualization of the dissimilarities, and remediate the dissimilarities using a variety of methods. A first remediation method includes verifying the dissimilarity using a single service provider, a second method includes verifying the dissimilarity leveraging multiple service providers, and a third method modifies the methods used to determine dissimilarities. After remediation, the network system can generate a map of the area that accurately represents the road network in the area.

Abstract: A network system uses a hybrid passive and active method for aggregating sensor data. The network system processes the sensor data to generate or update map information, which is used to coordinate geographic based services between users of the network system. In an embodiment, to leverage the idle time of users not actively providing services, the network system provides tasks for the users to collect sensor data for roads or points of interest (POIs) within a geographic region for which the network system is missing map information. The network system may determine that a user is more likely to complete a certain task if the target location for sensor data collection is nearby the user's current location. Thus, the network system is able to micro-target users with specific tasks, resulting in a greater likelihood of efficiently matching tasks to users.