Traffic API Developer's Guide

Limitations

To reduce the size and increase the relevance of traffic data, the Traffic API allows you to limit the area and detail of traffic flow data, traffic tiles, and incident data that you can obtain via queries. In addition, you can request tiles or incident reports for zoom levels 8 to 21 only.

Traffic Flow Data Limitations

The API restricts the maximum size of a geographical filter used to retrieve traffic flow data. The following limitations apply to requests that specify a bounding box and proximity filters:
  • Maximum width and height of a bounding box: 2 degrees of longitude and latitude
  • Maximum permitted proximity radius: 100km
  • Maximum allowed corridor length: 500km
  • Maximum allowed corridor width: 10km

Although requests that specify very large spatial filters do not result in an error response, the response specifies a limited amount of data, as described above.

Note: The HERE Service Agreement applies for the following recommended ranges:
  • Maximum size for a bounding box and a quadkey ( tile): 8-21
  • Maximum radius in proximity-based queries
For details on the HERE Service License Agreement, see the relevant documentation.

Traffic Tiles and Zoom Level

To avoid overcrowding the display, the display of tiles have the following limitations:
  • The traffic flow detail changes with the zoom level.
  • At low zoom levels, map tiles show traffic flow information only for the highest-level functional road classes. Traffic on minor roads become visible and more detailed as the zoom level increases.

For example:

  • At zoom level 14, traffic information is displayed on highways
  • At zoom level 15, traffic information is shown on highways and state roads

However, you may have access to a customized profile that displays different traffic flow data, depending on the zoom level.

The images below demonstrate traffic tile detail available at different zoom levels. The first two images contain no traffic information, because the zoom level is at 5, which is too low. As the zoom level increases in further tiles, traffic flow data on increasingly lower functional road classes become visible.

Figure 1. Zoom level too low to show traffic Tile at zoom level 5: too high to show traffic flow overlay.

In the image below, zoom level 8 shows some traffic flow information.

Figure 2. Zoom level 8 begins to show traffic flow overlay Tile at zoom level 8: begins to show traffic flow overlay.

The higher the zoom level, the more detailed the traffic flow display becomes:

Figure 3. Zoom level 14 shows more detailed traffic flow overlay Tile at zoom level 14: shows more detailed traffic flow overlay.

Traffic Incident and Zoom Level

Similar to the limitation of traffic flow data, the Traffic API has limitations on traffic incident information which prevent large response data transfers that are unsustainable:
  • No display of traffic incident information: zoom levels 0-7
  • Maximum bounding box width and height: 30 degrees of latitude and longitude
  • Maximum permitted size of the proximity radius: 100km
  • Maximum allowed corridor length: 500km
Note: Queries exceeding the limits in terms of zoom level or proximity radius result in an error response.