Get route attributes

Spans provide you with various granular route attributes. To use spans, specify the span parameter in your route request. You can specify spans=names,speedLimit to request all the street names and their speed limits.

As the spans refer to the polyline, you need to specify return=polyline as well.

curl -X GET \
  'https://router.hereapi.com/v8/routes?transportMode=car&origin=52.5308,13.3847&destination=52.5323,13.3789&return=polyline&spans=streetAttributes,length&apikey={YOUR_API_KEY}'

{
  "routes": [
    {
      "id": "7c090f54-e0fc-4591-9bec-e414ce5bca77",
      "sections": [
        {
          "arrival": {
            "place": {
              "location": {
                "lat": 52.53232637420297,
                "lng": 13.378873988986016
              },
              "type": "place"
            },
            "time": "2019-12-09T14:38:44+01:00"
          },
          "departure": {
            "place": {
              "location": {
                "lat": 52.53098367713392,
                "lng": 13.384566977620125
              },
              "type": "place"
            },
            "time": "2019-12-09T14:37:23+01:00"
          },
          "id": "d50b2080-0839-407c-9472-a5b23e756e23",
          "polyline": "BGwynmkDu39wZvBtFAA3InfAAvHrdAAvHvbAAoGzF0FnGoGvHsOvRAA8L3NAAkSnVAAoGjIsEzFAAgFvHkDrJAAwHrJoVvb0ezoBAAjInVAA3N_iBAAzJ_Z",
          "spans": [
            {
              "length": 113,
              "offset": 0,
              "streetAttributes": [
                "rightDrivingSide",
                "dividedRoad"
              ]
            },
            {
              "length": 425,
              "offset": 8,
              "streetAttributes": [
                "rightDrivingSide"
              ]
            }
          ],
          "transport": {
            "mode": "car"
          },
          "type": "vehicle"
        }
      ]
    }
  ]
}