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here-api

How to retreive speed limit from here maps given a latitude and longitude?

I'm trying to get speed limit from Here API maps but I can't find the way to do it. I tryed few example on web site but the only one that works is the one which require point of start and point of stop of the route.

I would like to get the speed limit given only one point ( or a box ). Which api do I have to use? Is there an example?

https://route.cit.api.here.com/routing/7.2/calculateroute.json?jsonAttributes=1&waypoint0=51.31854,9.51183&waypoint1=50.11208,8.68342&departure=2019-01-18T10:33:00&routeattributes=sh,lg&legattributes=li&linkattributes=nl,fc&mode=fastest;car;traffic:enabled&app_code=appcode&app_id=appid

This is the waypoint one but is not what I'm looking for, I would like to pass it only a Latitude / Longitude.

Thank you

Solution

  • You can achieve this by using PDE API(Platform Data Extension)

    1. You have to first map your geocordinates(lat,long) to a navigable position(lat,long) for the given coord and the Functional Class(FC1-5) it is located in. This you can achieve by a simple geocoder request
    2. You can calculate tilexy values based on the navigable lat,long and pass it to PDE API for querying speed limit layer on that particular FC class.

    Look at https://tcs.ext.here.com/examples/v3/link_speed_locator example which covers this exact usecase.

    Below is a sample geocoder request. Here prox parameter is your lat,long

    https://reverse.geocoder.cit.api.here.com/6.2/reversegeocode.json?app_id=xxxx&app_code=yyyy&prox=50.133848, 8.715332,500&mode=retrieveAddresses&maxResults=1&additionaldata=SuppressStreetType,Unnamed&locationattributes=linkInfo

    Below is a sample pde request 

    https://pde.cit.api.here.com/1/tiles.json?layers=SPEED_LIMITS_VAR_FC1,SPEED_LIMITS_VAR_FC2,SPEED_LIMITS_VAR_FC3,SPEED_LIMITS_VAR_FC4,SPEED_LIMITS_VAR_FC5,ROAD_GEOM_FC1,ROAD_GEOM_FC2,ROAD_GEOM_FC3,ROAD_GEOM_FC4,ROAD_GEOM_FC5&levels=9,10,11,12,13,9,10,11,12,13&tilexy=536,398,1073,797,2147,1594,4294,3188,8588,6377,536,398,1073,797,2147,1594,4294,3188,8588,6377&app_id=xxxx&app_code=yyyy

    Read more about it in the developer site - https://developer.here.com/documentation/platform-data/topics/quick-start-view-map-data.html

    Hope you find this useful!