Traffic API Limitations
To reduce the size and increase the relevance of traffic data, the service limits the area and detail of traffic data that you can request for traffic flow data, traffic tiles and incident data. You can request tiles or incident reports only for zoom levels 8-21.
Traffic Flow Data Limitations
The HERE Traffic API restricts the maximum size of a geographical filter used to retrieve traffic flow data. The limitation applies to requests that specify a bounding box and proximity filters. The width and height of a bounding box must be no greater than 10 degrees of longitude and latitude, while the maximum permitted proximity radius is 100km. The maximum allowed corridor length is 500km and width is 10km.
Queries using larger spatial filters will not result in an error response, but the amount of data returned will be according to the limitations specified above.
The recommended maximum size for a bounding box and quadkey (tile) is 1 degree of longitude and latitude. The largest recommended radius in proximity-based queries is 100km. For these ranges, the SLAs apply, which are documented separately.
Traffic Tiles and Zoom Level
The traffic flow detail changes with the zoom level so as not to overcrowd the display. At low zoom levels, map tiles show traffic flow information only for the highest-level functional road classes. Traffic on minor roads becomes visible and then more finely grained as the zoom level goes up (greater map detail is apparent).
- At zoom level 14, traffic information is displayed on highways
- At zoom level 15, traffic information is shown on highways and state roads
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 contain no traffic information, because the zoom level is too low at 5. As the zoom level increases in further tiles, traffic flow data on increasingly lower functional road classes become visible.
Some traffic flow information can be seen zoom level 8 in the following image.
The higher the zoom level, the more detailed the traffic flow display becomes:
Traffic Incident and Zoom Level
Mirroring its handling of traffic flow data, the HERE Traffic API does not return traffic incident information at zoom levels 0-7. A similar limitation applies to bounding box requests, with the maximum bounding box width and height restricted to 30 degrees of latitude and longitude. The largest permitted size of the proximity radius is 100km. The maximum allowed length for corridor is 500km. The effect of these limits is to prevent unsustainably large response data transfers.
Queries that exceed the limits in terms of zoom level or proximity radius result in an error response.