Documentation

Trace attributes

Last updated October 2, 2026

Snap a sequence of GPS coordinates to the road network and get back attributes along the matched path, such as speed limits, road class, and surface type. To get a route with directions instead, use map matching.

POSThttps://transit.land/api/v2/routing/valhalla/trace_attributes

Match a sequence of coordinates to the road network and return attributes along the matched path, such as speed limits, road class, and surface type.

Request

filtersoptional object

Include or exclude specific attribute keys from the response. If omitted, all attributes are returned.

filters.actionoptional string: Example:exclude
Values
include Include only the listed Onestop IDs; everything else is excluded.
exclude Exclude all listed Onestop IDs; everything else is included.
filters.attributesoptional array of strings: Attribute keys to include or exclude. Supports edge., node., matched., shape_attributes., and top-level keys such as shape, osm_changeset, and admin.*.

Values
`include`	Include only the listed Onestop IDs; everything else is excluded.
`exclude`	Exclude all listed Onestop IDs; everything else is included.

elevation_intervaloptional number

Elevation sample interval in meters along the matched path. 0 = disabled.

Default:0

encoded_polylineoptional string

Polyline6-encoded trace shape. Mutually exclusive with shape.

shapeoptional array of objects

GPS trace points. Mutually exclusive with encoded_polyline.

shape.date_timeoptional string: Per-location ISO 8601 datetime override, in the format YYYY-MM-DDTHH:MM, e.g. 2016-07-03T08:06.
shape.display_latoptional number: Latitude of the map location in degrees. If provided the lat and lon parameters will be treated as the routing location and the display_lat and display_lon will be used to determine the side of street. Both display_lat and display_lon must be provided and valid to achieve the desired effect.
shape.display_lonoptional number: Latitude of the map location in degrees. If provided the lat and lon parameters will be treated as the routing location and the display_lat and display_lon will be used to determine the side of street. Both display_lat and display_lon must be provided and valid to achieve the desired effect.
shape.headingoptional integer: Preferred approach heading in degrees.
shape.heading_toleranceoptional integer: How close in degrees a given street's angle must be in order for it to be considered as in the same direction of the heading parameter. The default value is service configuration dependent (60 by default).
shape.latnumberrequired
shape.lonnumberrequired
shape.minimum_reachabilityoptional integer: Minimum number of reachable edges for a snap candidate. The default and max values are service configuration dependent (50 and 100 by default, respectively).
Default:50
shape.nameoptional string: Label echoed in the response.
shape.node_snap_toleranceoptional number: Snap-to-node distance tolerance in meters. The default value is service dependent (5 by default).
shape.preferred_layeroptional integer: If set, edges whose layer does not match this value are discarded from candidate search. Note that this is a "soft" filter, meaning if no other candidates are found, Valhalla will fall back to including edges that did not match this filter.
shape.preferred_sideoptional string: Preferred side of road to snap to.
Default:eitherAllowed:same, opposite, eitherExample:opposite
shape.radiusoptional integer: Candidate search radius in meters: all viable edge candidates within the radius are correlated. If none are found, the best one outside the radius is correlated. The default is service dependent, and defaults to 0 (only the closest edge is considered as candidate). The max value is service configuration dependent (200 by default).
shape.rank_candidatesoptional boolean: Rank snap candidates by distance to input.
Default:true
shape.search_cutoffoptional integer: Hard cutoff for candidate search in meters. Default is service configuration dependent (35000 by default).
shape.search_filteroptional object: Optional filters to exclude candidate edges based on their attribution.
shape.streetoptional string: Street address hint for snapping.
shape.street_side_cutoffoptional string: Allowed:motorway, trunk, primary, secondary, tertiary, unclassified, residential, service_otherExample:primary
shape.street_side_max_distanceoptional integer: The max distance in meters that the input coordinates or display ll can be from the edge centerline for them to be used for determining the side of street. Beyond this distance the side of street is set to none. The default value is service configuration dependent (1000 by default).
shape.street_side_toleranceoptional integer: If your input coordinate is less than this tolerance away from the edge centerline then we set your side of street to none otherwise your side of street will be left or right depending on direction of travel. The default value is service configuration dependent (5 by default).
shape.typeoptional string: First and last location are always forced to break.
Default:breakExample:break
Values
break Stop here; starts or ends a route leg. Allows U-turns.
through Pass through without stopping. No U-turn; keeps direction of travel.
via Waypoint with a maneuver instruction but no leg-break. Allows U-turns.
break_through Like `break` but does not allow U-turns at the location.
shape.waitingoptional number: Waiting time in seconds at this stop (break/break_through only, not origin/destination).

Values
`break`	Stop here; starts or ends a route leg. Allows U-turns.
`through`	Pass through without stopping. No U-turn; keeps direction of travel.
`via`	Waypoint with a maneuver instruction but no leg-break. Allows U-turns.
`break_through`	Like `break` but does not allow U-turns at the location.

shape_formatoptional string

Not all formats are supported by all endpoints, e.g. no_shape is not valid for isochrone.

Default:polyline6Allowed:polyline6, polyline5, geojson, no_shapeExample:polyline6

shape_matchoptional string

Default:walk_or_snapExample:walk_or_snap

Values
`map_snap`	Map-matching algorithm for shapes that may not closely follow Valhalla edges, e.g. GPS traces. More expensive.
`edge_walk`	Exact edge-walking algorithm. Only use when the shape comes from a prior Valhalla route.
`walk_or_snap`	Try edge walking first; fall back to map snapping if it fails (default).

costingstringrequired

multimodal is not available. The street graph has no transit; use transit routing at /otp/plan.

Allowed:auto, bicycle, pedestrian, truck, bus, taxi, motor_scooter, motorcycle, bikeshare, auto_pedestrianExample:auto

costing_optionsoptional object

Costing options keyed by costing model name.

costing_options.autooptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.bicycleoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.bikeshareoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.busoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.motor_scooteroptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.motorcycleoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.pedestrianoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.taxioptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.
costing_options.truckoptional object: Options shared by all costing models. Parsed in src/sif/dynamiccost.cc.

date_timeoptional object

date_time.typeoptional integer: 0=current, 1=depart_at, 2=arrive_by, 3=invariant
Allowed:0, 1, 2, 3
date_time.valueoptional string: ISO 8601 local datetime string in the format YYYY-MM-DDTHH:MM, e.g. 2016-07-03T08:06. Required for types 1, 2, 3.

exclude_locationsoptional array of objects

A set of locations to exclude or avoid within a route.

exclude_locations.date_timeoptional string: Per-location ISO 8601 datetime override, in the format YYYY-MM-DDTHH:MM, e.g. 2016-07-03T08:06.
exclude_locations.display_latoptional number: Latitude of the map location in degrees. If provided the lat and lon parameters will be treated as the routing location and the display_lat and display_lon will be used to determine the side of street. Both display_lat and display_lon must be provided and valid to achieve the desired effect.
exclude_locations.display_lonoptional number: Latitude of the map location in degrees. If provided the lat and lon parameters will be treated as the routing location and the display_lat and display_lon will be used to determine the side of street. Both display_lat and display_lon must be provided and valid to achieve the desired effect.
exclude_locations.headingoptional integer: Preferred approach heading in degrees.
exclude_locations.heading_toleranceoptional integer: How close in degrees a given street's angle must be in order for it to be considered as in the same direction of the heading parameter. The default value is service configuration dependent (60 by default).
exclude_locations.latnumberrequired
exclude_locations.lonnumberrequired
exclude_locations.minimum_reachabilityoptional integer: Minimum number of reachable edges for a snap candidate. The default and max values are service configuration dependent (50 and 100 by default, respectively).
Default:50
exclude_locations.nameoptional string: Label echoed in the response.
exclude_locations.node_snap_toleranceoptional number: Snap-to-node distance tolerance in meters. The default value is service dependent (5 by default).
exclude_locations.preferred_layeroptional integer: If set, edges whose layer does not match this value are discarded from candidate search. Note that this is a "soft" filter, meaning if no other candidates are found, Valhalla will fall back to including edges that did not match this filter.
exclude_locations.preferred_sideoptional string: Preferred side of road to snap to.
Default:eitherAllowed:same, opposite, eitherExample:opposite
exclude_locations.radiusoptional integer: Candidate search radius in meters: all viable edge candidates within the radius are correlated. If none are found, the best one outside the radius is correlated. The default is service dependent, and defaults to 0 (only the closest edge is considered as candidate). The max value is service configuration dependent (200 by default).
exclude_locations.rank_candidatesoptional boolean: Rank snap candidates by distance to input.
Default:true
exclude_locations.search_cutoffoptional integer: Hard cutoff for candidate search in meters. Default is service configuration dependent (35000 by default).
exclude_locations.search_filteroptional object: Optional filters to exclude candidate edges based on their attribution.
exclude_locations.streetoptional string: Street address hint for snapping.
exclude_locations.street_side_cutoffoptional string: Allowed:motorway, trunk, primary, secondary, tertiary, unclassified, residential, service_otherExample:primary
exclude_locations.street_side_max_distanceoptional integer: The max distance in meters that the input coordinates or display ll can be from the edge centerline for them to be used for determining the side of street. Beyond this distance the side of street is set to none. The default value is service configuration dependent (1000 by default).
exclude_locations.street_side_toleranceoptional integer: If your input coordinate is less than this tolerance away from the edge centerline then we set your side of street to none otherwise your side of street will be left or right depending on direction of travel. The default value is service configuration dependent (5 by default).
exclude_locations.typeoptional string: First and last location are always forced to break.
Default:breakExample:break
Values
break Stop here; starts or ends a route leg. Allows U-turns.
through Pass through without stopping. No U-turn; keeps direction of travel.
via Waypoint with a maneuver instruction but no leg-break. Allows U-turns.
break_through Like `break` but does not allow U-turns at the location.
exclude_locations.waitingoptional number: Waiting time in seconds at this stop (break/break_through only, not origin/destination).

Values
`break`	Stop here; starts or ends a route leg. Allows U-turns.
`through`	Pass through without stopping. No U-turn; keeps direction of travel.
`via`	Waypoint with a maneuver instruction but no leg-break. Allows U-turns.
`break_through`	Like `break` but does not allow U-turns at the location.

exclude_polygonsoptional array or object

Array of coordinate rings [[lon,lat],…] or a GeoJSON FeatureCollection. Roads intersecting these rings will be avoided during path finding. Takes one of the 2 forms listed below.

array of arraysarray of arrays: Array of closed coordinate rings. All edges intersecting any ring are excluded.
objectobject: GeoJSON FeatureCollection. Each Feature may carry a properties.levels array to restrict exclusion to specific building/indoor levels in pedestrian routing.

formatoptional string

Not all formats are supported by all endpoints, e.g. geotiff is isochrone-only.

Default:jsonAllowed:json, gpx, osrm, pbf, geotiff, mvtExample:json

idoptional string

Arbitrary request identifier echoed in the response.

languageoptional string

BCP47 locale for narrative output. See locales/ for supported values.

Default:en-US

linear_cost_factorsoptional array of objects

Customized cost factors that influence path finding, specified as an array of JSON objects. Objects can be either a GeoJSON linestring feature and a "factor" property or a plain object with a "shape" key, whose value needs to be an encoded polyline (with 6 digit precision), and a "factor" key whose value needs to be float. Valhalla will perform an edge walk (see the map matching documentation for more info) to match the geometry onto edges and use those factors in costing. Edges with factors larger than 1 will be increasingly avoided, while edges with factors smaller than 1 increasingly favored.

object with shape, factorobject
object with type, geometry, propertiesobject

unitsoptional string

Default:kmAllowed:km, miles, mi

Response

adminsarray of objects

Countries and states the matched path passes through.

alternate_pathsarray of objects

Other plausible matches, when the trace was ambiguous.

confidence_scorenumber

How confident the matcher is, from 0 to 1.

edgesarray of objects

Edges the trace was matched onto, in order. Each carries the graph's own attributes, which follow the tile build. See the Valhalla map-matching reference for the full field list.

matched_pointsarray of objects

One entry per input point, describing how it was matched.

matched_points.distance_along_edgenumber: How far along that edge the point falls, from 0 to 1.
matched_points.distance_from_trace_pointnumber: Distance in meters from the input point to the matched point.
matched_points.edge_indexinteger: Index into edges of the edge this point matched.
matched_points.latnumber (double): Latitude of the matched point.
matched_points.lonnumber (double): Longitude of the matched point.
matched_points.typestring: Whether the point was matched, interpolated between matches, or left unmatched.
Allowed:matched, interpolated, unmatched

osm_changesetinteger

OpenStreetMap changeset the tiles were built from.

raw_scorenumber

Unnormalized matching score. Lower is a closer match.

shapestring

The matched path, as an encoded polyline.

unitsstring

Units the lengths are expressed in.

Allowed:kilometers, miles

curl -X POST "https://transit.land/api/v2/routing/valhalla/trace_attributes" \
  -H "apikey: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"costing":"auto","shape_match":"map_snap","shape":[{"lat":37.7891,"lon":-122.4011},{"lat":37.7887,"lon":-122.4016},{"lat":37.7883,"lon":-122.4022},{"lat":37.7879,"lon":-122.4028}]}'

Example responseShowing 2 of 3 edges, Showing 2 of 4 matched_points

{
  "units": "kilometers",
  "osm_changeset": 189768429,
  "shape": "shmagAtbwmhFnA`BbAxAjQnV",
  "confidence_score": 1,
  "raw_score": 200000096,
  "admins": [
    {
      "country_code": "US",
      "country_text": "United States",
      "state_code": "CA",
      "state_text": "California"
    }
  ],
  "edges": [
    {
      "truck_route": false,
      "density": 13,
      "sac_scale": 0,
      "shoulder": false,
      "sidewalk": "none",
      "bicycle_network": 0,
      "cycle_lane": "none",
      "lane_count": 1,
      "max_downward_grade": 0,
      "max_upward_grade": 0,
      "weighted_grade": 0,
      "mean_elevation": 8,
      "way_id": 47172320,
      "id": 3855242353202,
      "travel_mode": "drive",
      "vehicle_type": "car",
      "surface": "paved_smooth",
      "drive_on_right": true,
      "internal_intersection": false,
      "roundabout": false,
      "bridge": false,
      "tunnel": false,
      "unpaved": false,
      "toll": false,
      "use": "road",
      "traversability": "both",
      "end_shape_index": 1,
      "begin_shape_index": 0,
      "end_heading": 224,
      "begin_heading": 224,
      "road_class": "residential",
      "speed": 30,
      "speed_type": "classified",
      "speeds_non_faded": {
        "no_flow": 30
      },
      "country_crossing": false,
      "forward": true,
      "traffic_signal": false,
      "length": 0.006,
      "names": [
        "Stevenson Street"
      ],
      "end_node": {
        "intersecting_edges": [
          {
            "cyclability": "backward",
            "from_edge_name_consistency": false,
            "to_edge_name_consistency": false,
            "begin_heading": 315,
            "use": "cycleway",
            "road_class": "service_other"
          },
          {
            "cyclability": "forward",
            "from_edge_name_consistency": false,
            "to_edge_name_consistency": false,
            "begin_heading": 137,
            "use": "cycleway",
            "road_class": "service_other"
          }
        ],
        "elapsed_time": 0.72,
        "elapsed_cost": 0.846,
        "admin_index": 0,
        "type": "street_intersection",
        "traffic_signal": false,
        "fork": false,
        "transition_time": 0.008
      }
    },
    {
      "truck_route": false,
      "density": 13,
      "sac_scale": 0,
      "shoulder": false,
      "sidewalk": "none",
      "bicycle_network": 0,
      "cycle_lane": "none",
      "lane_count": 1,
      "max_downward_grade": 0,
      "max_upward_grade": 0,
      "weighted_grade": 0,
      "mean_elevation": 8,
      "way_id": 47172320,
      "id": 3928625895986,
      "travel_mode": "drive",
      "vehicle_type": "car",
      "surface": "paved_smooth",
      "drive_on_right": true,
      "internal_intersection": false,
      "roundabout": false,
      "bridge": false,
      "tunnel": false,
      "unpaved": false,
      "toll": false,
      "use": "road",
      "traversability": "both",
      "end_shape_index": 2,
      "begin_shape_index": 1,
      "end_heading": 226,
      "begin_heading": 226,
      "road_class": "residential",
      "speed": 30,
      "speed_type": "classified",
      "speeds_non_faded": {
        "no_flow": 30
      },
      "country_crossing": false,
      "forward": true,
      "traffic_signal": false,
      "length": 0.005,
      "names": [
        "Stevenson Street"
      ],
      "end_node": {
        "intersecting_edges": [
          {
            "walkability": "both",
            "from_edge_name_consistency": false,
            "to_edge_name_consistency": false,
            "begin_heading": 315,
            "use": "pedestrian_crossing",
            "road_class": "service_other"
          },
          {
            "walkability": "both",
            "from_edge_name_consistency": false,
            "to_edge_name_consistency": false,
            "begin_heading": 125,
            "use": "pedestrian_crossing",
            "road_class": "service_other"
          }
        ],
        "elapsed_time": 1.328,
        "elapsed_cost": 1.551,
        "admin_index": 0,
        "type": "street_intersection",
        "traffic_signal": false,
        "fork": false,
        "transition_time": 0.019
      }
    }
  ],
  "matched_points": [
    {
      "lon": -122.400826,
      "lat": 37.788826,
      "type": "matched",
      "edge_index": 0,
      "distance_along_edge": 0,
      "distance_from_trace_point": 38.559444
    },
    {
      "lon": -122.401297,
      "lat": 37.788458,
      "type": "matched",
      "edge_index": 2,
      "distance_along_edge": 0.701669,
      "distance_from_trace_point": 37.635989
    }
  ],
  "alternate_paths": []
}

See the Routing Platform overview for API access, travel modes, and the machine-readable schema.

Reference: Valhalla map matching API reference