Map Matching service API reference¶

With Valhalla's Map Matching service, you can match coordinates, such as GPS locations, to roads and paths that have been mapped in OpenStreetMap. By doing this, you can turn a path into a route with narrative instructions and also get the attribute values from that matched line.

You can view an interactive demo.

There are two separate Map Matching calls that perform different operations on an input set of latitude,longitude coordinates. The trace_route action returns the shape snapped to the road network and narrative directions, while trace_attributes returns detailed attribution along the portion of the route.

It is important to note that all service requests should be POST because shape or encoded_polyline can be fairly large.

Trace route action¶

The trace_route action takes the costing mode and a list of latitude,longitude coordinates, for example, from a GPS trace, to turn them into a route with the shape snapped to the road network and a set of guidance directions. You might use this to take a GPS trace from a bike route into a set of narrative instructions so you can re-create your trip or share it with others.

By default a single trip leg is returned in a trace_route response. You can split the route response into multiple legs by setting "type":"break" on any of the input shape objects in the shape parameter of your query. The first and last locations should always have type break. Note that setting breaks is not supported for encoded_polyline input, and is only supported for map_snap mode of the trace_route endpoint.

If the path contains one or more discontinuities (i.e. no path can be found between two locations), it is split into multiple paths. Any remaining paths from the first discontinuity onwards are stored as route alternates on the response.

Trace attributes action¶

The trace_attributes action takes the costing mode and a GPS trace or latitude,longitude positions and returns detailed attribution along the portion of the route. This includes details for each section of road along the path, as well as any intersections along the path. Some of the use cases for trace_attributes include getting:

just-in-time information for navigation. Getting attributes only for portions of the upcoming route can improve performance because returning full details along an entire route can create a very large payload. For example, regular route responses include shape and a set of maneuvers along each route leg. The maneuvers are a generalization of the path to simplify the description. Detailed attributes and localization of attributes along a maneuver would require significant additions to the route response. For long and even moderate length routes this can be wasteful, as the chances of re-routing along a long route are high.
speed limits. Speed limits along a path are a good example of just-in-time information that can be used for navigation. A single maneuver in a route (US-1, for example) may have many different speed limits along the full length of the maneuver. The trace_attributes action allows speed limits along each road segment to be determined and associated to portions of a maneuver.
way IDs. You can turn a GPS trace into a set of way IDs that match the trace.
the current road. A map-matching call with a recent set of GPS locations can be useful to find information about the current road, even if not doing navigation or having a route loaded on device.

Note that the attributes that are returned are Valhalla routing attributes, not the base OSM tags or base data. Valhalla imports OSM tags and normalizes many of them to a standard set of values used for routing. The default logic for the OpenStreetMap tags, keys, and values used when routing are documented on an OSM wiki page. To get the base OSM tags along a path, you need to take the OSM way IDs that are returned as attributes along the path and query OSM directly through a process such as the Overpass API.

Inputs of the Map Matching service¶

Shape-matching parameters¶

shape_match is an optional string input parameter. It allows some control of the matching algorithm based on the type of input.

shape_match type	Description
`edge_walk`	Indicates an edge walking algorithm can be used. This algorithm requires nearly exact shape matching, so it should only be used when the shape is from a prior Valhalla route.
`map_snap`	Indicates that a map-matching algorithm should be used because the input shape might not closely match Valhalla edges. This algorithm is more expensive.
`walk_or_snap`	Also the default option. This will try edge walking and if this does not succeed, it will fall back and use map matching.

Costing models and other options¶

Valhalla Map Matching can use any costing model available in the Valhalla route service except for multimodal (it would be difficult to get a GPS trace and detect certain mode changes). Refer to the route costing models and costing options documentation for more on how to specify this input.

You can also set directions_options to specify output units, language, and whether or not to return directions in a narrative form. Refer to the route options documentation for examples.

trace_route has additional options that allow more flexibility in specifying timestamps (when using encoded polyline input for the trace) and for using timestamps when computing elapsed time along the matched path. These options are:

Option	Description
`begin_time`	Begin timestamp for the trace. This is used along with the `durations` so that timestamps can be specified for a trace that is specified using an encoded polyline.
`durations`	List of durations (seconds) between each successive pair of input trace points. This allows trace points to be supplied as an encoded polyline and timestamps to be created by using this list of "delta" times along with the `begin_time` of the trace.
`use_timestamps`	A boolean value indicating whether the input timestamps or durations should be used when computing elapsed time at each edge along the matched path. If true, timestamps are used. If false (default), internal costing is applied to compute elapsed times.
`trace_options`	Additional options.
`trace_options.search_radius`	Search radius in meters associated with supplied trace points.
`trace_options.gps_accuracy`	GPS accuracy in meters associated with supplied trace points.
`trace_options.breakage_distance`	Breaking distance in meters between trace points.
`trace_options.interpolation_distance`	Interpolation distance in meters beyond which trace points are merged together.
`linear_references`	When present and `true`, the successful `trace_route` response will include a key `linear_references`. Its value is an array of base64-encoded OpenLR location references, one for each graph edge of the road network matched by the input trace.

Attribute filters (`trace_attributes` only)¶

The trace_attributes action allows you to apply filters to include or exclude specific attribute filter keys in your response. These filters are optional and can be added to the action string inside of the filters object.

If no filters are used, all attributes are enabled and returned in the trace_attributes response.

These are the available filter keys. Review their descriptions for more information.

// Edge filter Keys
edge.names
edge.length  # can also set source/target_percent_along
edge.speed
edge.road_class
edge.begin_heading
edge.end_heading
edge.begin_shape_index
edge.end_shape_index
edge.traversability
edge.use
edge.toll
edge.unpaved
edge.tunnel
edge.bridge
edge.roundabout
edge.internal_intersection
edge.drive_on_right
edge.surface
edge.sign.exit_number
edge.sign.exit_branch
edge.sign.exit_toward
edge.sign.exit_name
edge.travel_mode
edge.vehicle_type
edge.pedestrian_type
edge.bicycle_type
edge.transit_type
edge.id
edge.indoor
edge.way_id
edge.weighted_grade
edge.max_upward_grade
edge.max_downward_grade
edge.mean_elevation
edge.lane_count
edge.cycle_lane
edge.bicycle_network
edge.sac_scale
edge.shoulder
edge.sidewalk
edge.density
edge.speed_limit
edge.truck_speed
edge.truck_route
edge.country_crossing
edge.forward

// Node filter keys
node.intersecting_edge.begin_heading
node.intersecting_edge.from_edge_name_consistency
node.intersecting_edge.to_edge_name_consistency
node.intersecting_edge.driveability
node.intersecting_edge.cyclability
node.intersecting_edge.walkability
node.intersecting_edge.use
node.intersecting_edge.road_class
node.intersecting_edge.lane_count
node.elapsed_time
node.admin_index
node.type
node.fork
node.time_zone

// Other filter keys
osm_changeset
shape
admin.country_code
admin.country_text
admin.state_code
admin.state_text
matched.point
matched.type
matched.edge_index
matched.begin_route_discontinuity
matched.end_route_discontinuity
matched.distance_along_edge
matched.distance_from_trace_point

Outputs of the Map Matching service¶

Outputs of `trace_route`¶

The outputs of the trace_route action are the same as the outputs of a route action.

Outputs of `trace_attributes`¶

The trace_attributes results contains a list of edges and, optionally, the following items: osm_changeset, list of admins, shape, matched_points, and units.

Result item	Description
`edges`	List of edges associated with input shape. See the list of edge items for details.
`osm_changeset`	Identifier of the OpenStreetMap base data version.
`admins`	List of the administrative codes and names. See the list of admin items for details.
`shape`	The encoded polyline of the matched path.
`matched_points`	List of match results when using the `map_snap` shape match algorithm. There is a one-to-one correspondence with the input set of latitude, longitude coordinates and this list of match results. See the list of matched point items for details.
`units`	The specified units with the request, in either kilometers or miles.
`warnings`	A warnings array. This array may contain descriptive text about notices of deprecated request parameters, clamped values etc.

Edge items¶

Each edge may include:

Edge item	Description
`names`	List of names.
`source_percent_along`	The start of an edge's match as percentage of its length in (0, 1) range. If an edge was fully matched, we omit this value.
`target_percent_along`	The end of an edge's match as percentage of its length in (0, 1) range. If an edge was fully matched, we omit this value.
`length`	The matched edge length in the units specified (default is kilometers). If `source_percent_along` and/or `target_percent_along` are present, this represents the partially matched edge length, otherwise the full edge length.
`speed`	Edge speed in the units specified. The default is kilometers per hour.
`road_class`	Road class values: `motorway` `trunk` `primary` `secondary` `tertiary` `unclassified` `residential` `service_other`
`begin_heading`	The direction at the beginning of an edge. The units are degrees from north in a clockwise direction.
`end_heading`	The direction at the end of an edge. The units are degrees from north in a clockwise direction..
`begin_shape_index`	Index into the list of shape points for the start of the edge.
`end_shape_index`	Index into the list of shape points for the end of the edge.
`traversability`	Traversability values, if available: `forward` `backward` `both`
`use`	Use values: `tram` `road` `ramp` `turn_channel` `track` `driveway` `alley` `parking_aisle` `emergency_access` `drive_through` `culdesac` `cycleway` `mountain_bike` `sidewalk` `footway` `steps` `other` `rail-ferry` `ferry` `rail` `bus` `egress_connection` `platform_connection` `transit_connection`
`toll`	True if the edge has any toll.
`unpaved`	True if the edge is unpaved or rough pavement.
`tunnel`	True if the edge is a tunnel.
`bridge`	True if the edge is a bridge.
`roundabout`	True if the edge is a roundabout.
`internal_intersection`	True if the edge is an internal intersection.
`drive_on_right`	True if the flag is enabled for driving on the right side of the street.
`surface`	Surface values: `paved_smooth` `paved` `paved_rough` `compacted` `dirt` `gravel` `path` `impassable`
`sign`	Contains the interchange guide information associated with this edge. See the list of sign items for details.
`travel_mode`	Travel mode values: `drive` `pedestrian` `bicycle` `transit`
`vehicle_type`	Vehicle type values: `car` `motorcycle` `bus` `tractor_trailer`
`pedestrian_type`	Pedestrian type values: `foot` `wheelchair` `segway`
`bicycle_type`	Bicycle type values: `road` `cross` `hybrid` `mountain`
`transit_type`	Transit type values: `tram` `metro` `rail` `bus` `ferry` `cable_car` `gondola` `funicular`
`id`	Identifier of an edge within the tiled, hierarchical graph.
`indoor`	Whether or not the edge is inside of a building or structure or not.
`way_id`	Way identifier of the OpenStreetMap base data.
`weighted_grade`	The weighted grade factor. Valhalla manufactures a `weighted_grade` from elevation data. It is a measure used for hill avoidance in routing - sort of a relative energy use along an edge. But since an edge in Valhalla can possibly go up and down over several hills it might not equate to what most folks think of as grade.
`max_upward_grade`	The maximum upward slope. A value of 32768 indicates no elevation data is available for this edge.
`max_downward_grade`	The maximum downward slope. A value of 32768 indicates no elevation data is available for this edge.
`mean_elevation`	The mean or average elevation along the edge. Units are meters by default. If the units are specified as miles, then the mean elevation is returned in feet. A value of 32768 indicates no elevation data is available for this edge.
`lane_count`	The number of lanes for this edge.
`cycle_lane`	The type (if any) of bicycle lane along this edge.
`bicycle_network`	The bike network for this edge.
`sac_scale`	Classification of hiking trails based on difficulty. Values: `0 - No Sac Scale` `1 - Hiking` `2 - Mountain hiking` `3 - Demanding mountain hiking` `4 - Alpine hiking` `5 - Demanding alpine hiking` `6 - Difficult alpine hiking`
`shoulder`	True if the edge has a shoulder.
`sidewalk`	Sidewalk values: `left` `right` `both`
`density`	The relative density along the edge.
`speed_limit`	Edge speed limit in the units specified. The default is kilometers per hour.
`truck_speed`	Edge truck speed in the units specified. The default is kilometers per hour.
`truck_route`	True if edge is part of a truck network/route.
`end_node`	The node at the end of this edge. See the list of end node items for details.
`landmarks`	List of landmarks along the edge. They are used as direction support in navigation.
`country_crossing`	True if the edge is a country crossing.
`forward`	True if the edge is traversed forwards and False if it is traversed backwards with respect to the reference shape/geometry (ie. the direction in which it was digitized).

Sign items¶

Each sign may include:

Sign item	Description
`exit_number`	List of exit number elements. If an exit number element exists, it is typically just one value. Element example: `91B`
`exit_branch`	List of exit branch elements. An exit branch element is the subsequent road name or route number after the sign. Element example: `I 95 North`
`exit_toward`	List of exit toward elements. The exit toward element is the location where the road ahead goes; the location is typically a control city, but may also be a future road name or route number. Element example: `New York`
`exit_name`	List of exit name elements. The exit name element is the interchange identifier, although typically not used in the United States. Element example: `Gettysburg Pike`

End node items¶

Each end_node may include:

Node item	Description
`intersecting_edges`	List of intersecting edges at this node. See the list of intersecting edge items for details.
`elapsed_time`	Elapsed time of the path to arrive at this node.
`admin_index`	Index value in the admin list.
`type`	Node type values: `street_intersection` `gate` `bollard` `toll_booth` `multi_use_transit_stop` `bike_share` `parking` `motor_way_junction` `border_control`
`fork`	True if this node is a fork.
`time_zone`	Time zone string for this node.

Intersecting edge items¶

Each intersecting_edge may include:

Intersecting edge item	Description
`begin_heading`	The direction at the beginning of this intersecting edge. The units are degrees from north in a clockwise direction.
`from_edge_name_consistency`	True if this intersecting edge at the end node has consistent names with the path `from edge`.
`to_edge_name_consistency`	True if this intersecting edge at the end node has consistent names with the path `to edge`.
`driveability`	Driveability values, if available: `forward` `backward` `both`
`cyclability`	Cyclability values, if available: `forward` `backward` `both`
`walkability`	Walkability values, if available: `forward` `backward` `both`
`use`	Use values: `tram` `road` `ramp` `turn_channel` `track` `driveway` `alley` `parking_aisle` `emergency_access` `drive_through` `culdesac` `cycleway` `mountain_bike` `sidewalk` `footway` `steps` `other` `rail-ferry` `ferry` `rail` `bus` `egress_connection` `platform_connection` `transit_connection`
`road_class`	Road class values: `motorway` `trunk` `primary` `secondary` `tertiary` `unclassified` `residential` `service_other`

Admin items¶

Each admin may include:

Admin item	Description
`country_code`	Country ISO 3166-1 alpha-2 code.
`country_text`	Country name.
`state_code`	State code.
`state_text`	State name.

Matched point items¶

Each matched_point may include:

Matched point item	Description
`lat`	The latitude of the matched point.
`lon`	The longitude of the matched point.
`type`	Describes the type of this match result - possible values include: `unmatched` `interpolated` `matched`
`edge_index`	The index of the edge in the list of edges that this matched point is associated with. This value will not exist if this point was unmatched.
`begin_route_discontinuity`	The boolean value is true if this match result is the begin location of a route disconnect. This value will not exist if this is false.
`end_route_discontinuity`	The boolean value is true if this match result is the end location of a route disconnect. This value will not exist if this is false.
`distance_along_edge`	The distance along the associated edge for this matched point. For example, if the matched point is halfway along the edge then the value would be 0.5. This value will not exist if this point was unmatched.
`distance_from_trace_point`	The distance in meters from the trace point to the matched point. This value will not exist if this point was unmatched.

Get better results¶

Follow these guidelines to improve the Map Matching results.

You should have good GPS accuracy, meaning that there are few obstructions affecting GPS signals. This can be difficult in urban areas.
Make sure the trace point density is within the approximate range of one per second and one per 10 seconds. The greater the range between them, the more chance of inaccurate results.
Have each trace represent one continuous path.
Verify that there is a corresponding match with the OpenStreetMap network.

You can use certain parameters to tune the response. Unless otherwise noted, each of these options is specified within a root-level trace_options object.

Use turn_penalty_factor to penalize turns from one road segment to next. For a pedestrian trace_route, you may see a back-and-forth motion along the streets of your path. Try increasing the turn penalty factor to 500 to smooth out jittering of points. Note that if GPS accuracy is already good, increasing this will have a negative affect on your results.
Set the gps_accuracy to indicate the accuracy in meters.
Apply a search_radius to specify the search radius (in meters) within which to search road candidates for each measurement. The maximum search radius is 100 meters. Note that performance may decrease with a higher search radius value.
Add a time component to your GPS data to inform the map matching algorithm about when the point was measured. Providing a time attribute is not available for encoded_polyline data and can only be specified with GPS data provided by the shape attribute. time is specified in seconds and can be a UNIX epoch time or any increasing sequence:
```
{"shape":[{"lat":39.983841,"lon":-76.735741,"time":0},{"lat":39.983704,"lon":-76.735298,"time":2},{"lat":39.983578,"lon":-76.734848,"time":6},...]}
```

Example Map Matching requests¶

Example `trace_route` requests¶

The following are example JSON payloads for POST requests for the trace_routes action.

trace_route with shape parameter

{"shape":[{"lat":39.983841,"lon":-76.735741,"type":"break"},{"lat":39.983704,"lon":-76.735298,"type":"via"},{"lat":39.983578,"lon":-76.734848,"type":"via"},{"lat":39.983551,"lon":-76.734253,"type":"break"},{"lat":39.983555,"lon":-76.734116,"type":"via"},{"lat":39.983589,"lon":-76.733315,"type":"via"},{"lat":39.983719,"lon":-76.732445,"type":"via"},{"lat":39.983818,"lon":-76.731712,"type":"via"},{"lat":39.983776,"lon":-76.731506,"type":"via"},{"lat":39.983696,"lon":-76.731369,"type":"break"}],"costing":"auto","shape_match":"map_snap"}}

trace_route with encoded polyline parameter

{"encoded_polyline":"_grbgAh~{nhF?lBAzBFvBHxBEtBKdB?fB@dBZdBb@hBh@jBb@x@\\|@x@pB\\x@v@hBl@nBPbCXtBn@|@z@ZbAEbAa@~@q@z@QhA]pAUpAVhAPlAWtASpAAdA[dASdAQhAIlARjANnAZhAf@n@`A?lB^nCRbA\\xB`@vBf@tBTbCFbARzBZvBThBRnBNrBP`CHbCF`CNdCb@vBX`ARlAJfADhA@dAFdAP`AR`Ah@hBd@bBl@rBV|B?vB]tBCvBBhAF`CFnBXtAVxAVpAVtAb@|AZ`Bd@~BJfA@fAHdADhADhABjAGzAInAAjAB|BNbCR|BTjBZtB`@lBh@lB\\|Bl@rBXtBN`Al@g@t@?nAA~AKvACvAAlAMdAU`Ac@hAShAI`AJ`AIdAi@bAu@|@k@p@]p@a@bAc@z@g@~@Ot@Bz@f@X`BFtBXdCLbAf@zBh@fBb@xAb@nATjAKjAW`BI|AEpAHjAPdAAfAGdAFjAv@p@XlAVnA?~A?jAInAPtAVxAXnAf@tBDpBJpBXhBJfBDpAZ|Ax@pAz@h@~@lA|@bAnAd@hAj@tAR~AKxAc@xAShA]hAIdAAjA]~A[v@BhB?dBSv@Ct@CvAI~@Oz@Pv@dAz@lAj@~A^`B^|AXvAVpAXdBh@~Ap@fCh@hB\\zBN`Aj@xBFdA@jALbAPbAJdAHdAJbAHbAHfAJhALbA\\lBTvBAdC@bC@jCKjASbC?`CM`CDpB\\xAj@tB\\fA\\bAVfAJdAJbAXz@L|BO`AOdCDdA@~B\\z@l@v@l@v@l@r@j@t@b@x@b@r@z@jBVfCJdAJdANbCPfCF|BRhBS~BS`AYbAe@~BQdA","shape_match":"map_snap","costing":"pedestrian","directions_options":{"units":"miles"}}

trace_route with additional trace options

{"encoded_polyline":"{gmagAp~_nhF[_AZqAjAaB`AkB\\cAZeAPcAHiAKiCQaAUeAe@cA]qAQsACqAF}AIsAg@{@s@i@sAw@i@uANyAPsAv@cAZ_ALqA_@cA_Ai@q@w@[uAm@}AaAqAs@s@m@u@c@oA]mAMiAIkAYqBRyATsANsBKyBAiA?iAFsALuAPsAXaBGgCg@oBKiBf@iBGiBg@oBHqA?{Ai@cA@oAbAgAj@g@j@k@n@q@p@e@n@k@d@}@\\cAFgAIoBg@m@y@[_ASu@K{AHgBP{@@w@Jy@L}@JsAMoAe@kAq@kAk@gAg@y@a@m@g@q@mAo@e@gAc@sAA_AI_BFu@LiALaALaAHoAFiAF{A@yABkAKmAKcAMiBU}AYu@MaBUqBu@{As@iAaAaA_Ao@aAi@s@q@{@{@a@sAi@oAGeAD}@[YiAmA[u@BgBXaBHgAQ}@]s@S]x@_BbC}@lAw@dAs@dAk@dAm@z@s@n@y@p@{@`Ao@z@_@z@u@jA_Af@aANiAAcBPsAl@s@X}@T{@PoAPeAl@{@t@_AbAgAjBk@r@e@~AY~@U~@YhAi@lAo@t@kBb@u@NyAX{@k@MoAi@{@eAx@aArAmBt@_ALgAPiAXkAf@w@j@u@p@_A^aA\\aA`@eAt@eATcAGcAG}@AeAX_Aj@q@r@aAp@wAt@sARk@xA?pBAvAu@Ps@_Bk@i@y@\\s@f@o@j@u@f@{@RwAb@mAZaARkATqANyAImAK}@C_AFqADiAC_AUs@[}Ao@eBm@q@_@_Bg@iAm@kAaAc@s@c@w@y@{AWcAc@{Am@c@yBF{@AkAYmA_@uBD{@B{@Gu@ScBIu@NaB^_B`@sAC{Ac@}A]yAg@aBHuAJ_BAaAEgAA_AAy@@eBX_AFw@JcB^s@VuA`AuAl@kBl@_AFeAJcAB{ABwAj@o@l@q@b@u@Z{AXmAaAm@o@oAwAsAcAsAu@u@cAe@iAy@eAk@iAc@gAOgAWgBe@wAo@}Ai@sBY{@u@s@y@Y{@[aA]s@oB\\eCPoARwAXgBV{Ab@sAf@oAb@kAFsA?kACeADeA^aABeAO_Be@gB]}@eAaB_AoAw@aAm@o@q@cBp@eBz@a@fAi@|@o@LiBAyAIoAu@qBkAuAiAa@gAa@cB_@eAQm@c@o@{ANaBf@{@h@_BV}@XcBz@?{@s@o@y@u@}@mAaBw@qCm@mG}@uJLoBVkBVaBh@iB`@gBXgBZ_BZaBNgACwASyAUqAGuBGsBTcBRiB^eCTmBTaBNoAVaB@kAMiBZcAd@eAf@q@z@mAVgB[gAq@aAk@s@UkAG{B_@sAW}ASoBMwBSuB]gBq@eBs@eBaAuAaAeAo@{@i@}@e@{@g@{@m@m@y@_@y@[aBk@a@cBFsB[iAaAGoA`@IcC^yA`@}AVkBNwBBmBR_Cr@{CrAyD|@mCf@kBXeB\\eBl@aCf@cBc@sBg@qAUkBe@sBw@eBi@uA{@gAyAc@qAk@[wB@gARqANgAPiAJsAAeAa@mBKmB@uBBwB@oBZoBJkCJkANaCY}Ac@aBa@iBc@iBu@qBu@sBu@sB_AiBcA}AiAqAaAqAeAaA}@]iANgAj@}@dAcAhAeAfAyAfAo@`@k@f@o@f@s@d@o@f@k@h@o@`@s@V_Br@wAv@{An@uAt@qAj@wAl@iAv@gA~@qAbA{A`AcBz@o@^{A`AmAhAo@b@sAxA_@z@]x@a@t@qAxAk@j@qAfAm@b@m@b@kAfAuA~@eAhAcAbAiAr@qA|@gAdAcA`A{@bA_AhAgA|@mAr@qA|@mAlA","shape_match":"map_snap","costing":"pedestrian","trace_options":{"turn_penalty_factor":500},"directions_options":{"units":"miles"}}

Example `trace_attributes` requests¶

The following are example JSON payloads for POST requests for the trace_attributes action.

trace_attributes with shape parameter

{"shape":[{"lat":39.983841,"lon":-76.735741},{"lat":39.983704,"lon":-76.735298},{"lat":39.983578,"lon":-76.734848},{"lat":39.983551,"lon":-76.734253},{"lat":39.983555,"lon":-76.734116},{"lat":39.983589,"lon":-76.733315},{"lat":39.983719,"lon":-76.732445},{"lat":39.983818,"lon":-76.731712},{"lat":39.983776,"lon":-76.731506},{"lat":39.983696,"lon":-76.731369}],"costing":"auto","shape_match":"walk_or_snap","filters":{"attributes":["edge.names","edge.id", "edge.weighted_grade","edge.speed"],"action":"include"}}

trace_attributes with encoded polyline parameter

{"encoded_polyline":"_grbgAh~{nhF?lBAzBFvBHxBEtBKdB?fB@dBZdBb@hBh@jBb@x@\\|@x@pB\\x@v@hBl@nBPbCXtBn@|@z@ZbAEbAa@~@q@z@QhA]pAUpAVhAPlAWtASpAAdA[dASdAQhAIlARjANnAZhAf@n@`A?lB^nCRbA\\xB`@vBf@tBTbCFbARzBZvBThBRnBNrBP`CHbCF`CNdCb@vBX`ARlAJfADhA@dAFdAP`AR`Ah@hBd@bBl@rBV|B?vB]tBCvBBhAF`CFnBXtAVxAVpAVtAb@|AZ`Bd@~BJfA@fAHdADhADhABjAGzAInAAjAB|BNbCR|BTjBZtB`@lBh@lB\\|Bl@rBXtBN`Al@g@t@?nAA~AKvACvAAlAMdAU`Ac@hAShAI`AJ`AIdAi@bAu@|@k@p@]p@a@bAc@z@g@~@Ot@Bz@f@X`BFtBXdCLbAf@zBh@fBb@xAb@nATjAKjAW`BI|AEpAHjAPdAAfAGdAFjAv@p@XlAVnA?~A?jAInAPtAVxAXnAf@tBDpBJpBXhBJfBDpAZ|Ax@pAz@h@~@lA|@bAnAd@hAj@tAR~AKxAc@xAShA]hAIdAAjA]~A[v@BhB?dBSv@Ct@CvAI~@Oz@Pv@dAz@lAj@~A^`B^|AXvAVpAXdBh@~Ap@fCh@hB\\zBN`Aj@xBFdA@jALbAPbAJdAHdAJbAHbAHfAJhALbA\\lBTvBAdC@bC@jCKjASbC?`CM`CDpB\\xAj@tB\\fA\\bAVfAJdAJbAXz@L|BO`AOdCDdA@~B\\z@l@v@l@v@l@r@j@t@b@x@b@r@z@jBVfCJdAJdANbCPfCF|BRhBS~BS`AYbAe@~BQdA","shape_match":"map_snap","costing":"pedestrian","directions_options":{"units":"miles"}}

trace_attributes with include attribute filter

{"shape":[{"lat":39.983841,"lon":-76.735741},{"lat":39.983704,"lon":-76.735298},{"lat":39.983578,"lon":-76.734848},{"lat":39.983551,"lon":-76.734253},{"lat":39.983555,"lon":-76.734116},{"lat":39.983589,"lon":-76.733315},{"lat":39.983719,"lon":-76.732445},{"lat":39.983818,"lon":-76.731712},{"lat":39.983776,"lon":-76.731506},{"lat":39.983696,"lon":-76.731369}],"costing":"auto","shape_match":"walk_or_snap","filters":{"attributes":["edge.names","edge.id", "edge.weighted_grade","edge.speed"],"action":"include"}}

trace_attributes with exclude attribute filter

{"shape":[{"lat":39.983841,"lon":-76.735741},{"lat":39.983704,"lon":-76.735298},{"lat":39.983578,"lon":-76.734848},{"lat":39.983551,"lon":-76.734253},{"lat":39.983555,"lon":-76.734116},{"lat":39.983589,"lon":-76.733315},{"lat":39.983719,"lon":-76.732445},{"lat":39.983818,"lon":-76.731712},{"lat":39.983776,"lon":-76.731506},{"lat":39.983696,"lon":-76.731369}],"costing":"auto","shape_match":"walk_or_snap","filters":{"attributes":["edge.names","edge.begin_shape_index","edge.end_shape_index","shape"],"action":"exclude"}}

If you would like to visualize the map matched points that correlate to specified input locations - use the following filter

"filters":{"attributes":["edge.id","matched.point","matched.type","matched.edge_index","matched.begin_route_discontinuity","matched.end_route_discontinuity","matched.distance_along_edge"],"action":"include"}