Optional. Default: For public HERE maps all maps/regions containing the layer are returned, for private BYOD maps the layers from the DEFAULT map are returned

Comma separated list of PDE layer names, to get link attributes along the route. Only link attribute layers (roughly those ending in FC1, FC2 ... ) are supported. Specify FCn to get the layers of all functional classes. Behind each layer name attributes can be listed, or (*) to get all. Example: &attributes=ROAD_GEOM_FCn(TUNNEL), SPEED_LIMITS_FCn (FROM_REF_SPEED_LIMIT, TO_REF_SPEED_LIMIT), ADAS_ATTRIB_FCn (SLOPES). A maximum of 32 layers can be requested per request.

Semicolon separated list of one or multiple disconnected topology segment references. Format of a SegmentRef is [Segment Identifier:]Segment Ref Id#Start Offset[..End Offset][,LAT,LON][,Remaining Time On Route,Functional Class]. Please use here:xs1:segment as the segment identifier for Japan segmentRefs and here:cm:segment for segmentRefs from rest of the world. The input is typically retrieved from the Geocoding&Search (Reverse Geocoding) API.

A key generated specifically to authenticate API requests. For more information on how to get an API key, see https://developer.here.com/documentation/identity-access-management/dev_guide/index.html .
Other authentication options are Bearer token, see https://developer.here.com/documentation/identity-access-management/dev_guide/index.html or app_id with app_code for backward compatibility.