OptionalboundingWGS84 [minLongitude, minLatitude, maxLongitude, maxLatitude].
OptionalcountyOptionalmunicipalityOptionalpageOptionalroadExisting-road categories. They map to NVDB references EV/RV/FV/KV/PV/SV.
OptionalstartOpaque continuation marker returned by the preceding response.
Filters accepted when reading segmented NVDB road-network links.