Map Tile API Developer's Guide

Traffic Tiles

The Map Tile API China provides traffic tiles that you can use to display the traffic flow on the road network and to highlight congestion.

Traffic Coverage

The API supports traffic tiles for the regions listed in Traffic Coverage.

Traffic Visualization

Traffic tiles display the traffic flow on the roads: they reflect the traffic congestion on the road network, which is presented to the user by color coded lines drawn along the affected streets and roads. The traffic congestion displays four congestion levels:

  • Free Flow (green): Road segments where the average speed of the traffic is around the expected free flow speed, mostly due to a small volume of cars.
  • Heavy (yellow): Road segments with a higher volume of cars, which would lead to an average speed that is less than the expected free flow speed.
  • Queuing (red): Road segments with a very high volume of cars that would lead to an average speed closer to stopping and that would reduce the distance between two (2) successive vehicles, which would have the effect of creating a queue.
  • Blocked (black): Road segments that are blocked, due to temporary issues such as construction sites and accidents..

Traffic Tile Types

The Map Tile API China can render the traffic tile type as shown below.

Flow Tile
transparent tile with only traffic flow

The following additional traffic tile types will be available at a later point:

Traffic Tile Flow Base Tile Flow and Label Tile
map tile with traffic flow base tile (no labels) with traffic flow tile with traffic flow and labels

Rendering by Traffic Congestion Levels

Based on the congestion levels described in Traffic Visualization, the API can render traffic lines only for road segments where a traffic reaches a minimum congestion level.

free traffic and above heavy traffic and above queuing traffic and above

Validity of Traffic Data

It is important to note that traffic information remains valid only for a short period of time (about 1-5 minutes). For this reason, client applications should not cache traffic tiles.