Traffic API supports the standard HTTP headers.
- Expires HTTP Header estimates when fresh data for the requested area will be available next time. It includes some randomization to spread load.
- If the estimation was wrong and there is no fresh data, Expires will be set a smaller value that the customer knows to download data again.
- If there are multiple tables in the requested area, TDA Service will send the earliest Expires value.
- Max-age in the Cache-Control HTTP Header will be in sync with Expires.
- Last-Modified will have the latest timestamp from the Traffic Feeds in the requested area.
- ETag is supported for the traffic tiles.