16. One or more computer-readable storage devices having stored thereon a data structure, comprising: an end time index that contains entries corresponding to a plurality of end times for segments that have common spatial relationships; a plurality of start time indexes, each start time index containing entries for start times of segments that have end times within a time range corresponding to that index; and wherein the data structure may be identified relative to other data structures based on spatial data, and searched via temporal data to determine from the start times and end times one or more tracks that are associated with one or more segments that correspond to the temporal data.
16. One or more computer-readable storage devices having stored thereon a data structure, comprising: an end time index that contains entries corresponding to a plurality of end times for segments that have common spatial relationships; a plurality of start time indexes, each start time index containing entries for start times of segments that have end times within a time range corresponding to that index; and wherein the data structure may be identified relative to other data structures based on spatial data, and searched via temporal data to determine from the start times and end times one or more tracks that are associated with one or more segments that correspond to the temporal data. 18. The one or more computer-readable storage devices of claim 16 wherein the start time of each segment is used as a key to the start time index to determine which track is associated with that segment.