Documentation

Map matching

Last updated October 2, 2026

Snap a sequence of GPS coordinates to the road network and get back a route with turn-by-turn directions. To get road attributes along the matched path instead, use trace attributes.

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

Match a sequence of coordinates to the road network and return the matched route with turn-by-turn directions.

Request

alternatesoptional integer

Number of alternative matched routes to return.

Default:0

begin_timeoptional integer

Epoch start timestamp (seconds) for the trace. Used with durations to assign timestamps to encoded_polyline input.

directions_typeoptional string

Default:instructions

Values
`none`	No maneuvers or instructions.
`maneuvers`	Maneuvers only, no narrative text.
`instructions`	Maneuvers with narrative instructions (default).

durationsoptional array of numbers

Elapsed seconds between each successive pair of trace points. Used with begin_time to derive per-point timestamps from an encoded_polyline input.

linear_referencesoptional boolean

Include base64-encoded OpenLR location references for each matched graph edge.

Default:false

trace_optionsoptional object

Fine-tuning parameters for the map-matching algorithm.

trace_options.breakage_distanceoptional number: Maximum gap in meters between trace points before starting a new segment.
trace_options.gps_accuracyoptional number: GPS accuracy in meters associated with trace points.
trace_options.interpolation_distanceoptional number: Distance in meters beyond which trace points are merged together.
trace_options.search_radiusoptional number: Search radius in meters for road candidates per trace point.
trace_options.turn_penalty_factoroptional number: Penalty for sharp turns. Increase (e.g. 500) to smooth pedestrian traces.

use_timestampsoptional boolean

When true, use per-point time values (or derived timestamps) for elapsed time calculation instead of internal costing.

Default:false

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

tripobject

A route through the network, split into legs between the requested locations.

trip.languagestring

Language tag the narrative instructions are written in.

Example:en-US

trip.legsarray of objects

One leg per consecutive pair of break locations.

trip.legs.maneuversarray of objects

Turn-by-turn steps. Absent when directions_type is none.

trip.legs.shapestring

The leg's geometry, encoded per the request's shape_format, which defaults to a polyline at six digits of precision.

trip.legs.summaryobject

Totals for a trip or a single leg.

trip.locationsarray of objects

The requested locations, snapped to the network and in the order visited.

trip.statusinteger

Zero on success.

Example:0

trip.status_messagestring

Human-readable form of status.

Example:Found route between points

trip.summaryobject

Totals for a trip or a single leg.

trip.unitsstring

Units the lengths in this trip are expressed in.

Allowed:kilometers, miles

trip.warningsarray of objects

Non-fatal notes about the request, such as a parameter that was ignored. Absent when there are none.

curl -X POST "https://transit.land/api/v2/routing/valhalla/trace_route" \
  -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 response

{
  "trip": {
    "locations": [
      {
        "type": "break",
        "lat": 37.7891,
        "lon": -122.4011,
        "original_index": 0
      },
      {
        "type": "via",
        "lat": 37.7887,
        "lon": -122.4016,
        "original_index": 1
      }
    ],
    "legs": [
      {
        "maneuvers": [
          {
            "type": 1,
            "instruction": "Drive southwest on Stevenson Street.",
            "verbal_succinct_transition_instruction": "Drive southwest. Then You will arrive at your destination.",
            "verbal_pre_transition_instruction": "Drive southwest on Stevenson Street. Then You will arrive at your destination.",
            "verbal_post_transition_instruction": "Continue for 60 meters.",
            "street_names": [
              "Stevenson Street"
            ],
            "bearing_after": 224,
            "time": 6.904,
            "length": 0.057,
            "cost": 8.08,
            "begin_shape_index": 0,
            "end_shape_index": 3,
            "verbal_multi_cue": true,
            "travel_mode": "drive",
            "travel_type": "car"
          },
          {
            "type": 4,
            "instruction": "You have arrived at your destination.",
            "verbal_transition_alert_instruction": "You will arrive at your destination.",
            "verbal_pre_transition_instruction": "You have arrived at your destination.",
            "bearing_before": 225,
            "time": 0,
            "length": 0,
            "cost": 0,
            "begin_shape_index": 3,
            "end_shape_index": 3,
            "travel_mode": "drive",
            "travel_type": "car"
          }
        ],
        "summary": {
          "has_time_restrictions": false,
          "has_toll": false,
          "has_highway": false,
          "has_ferry": false,
          "min_lat": 37.788458,
          "min_lon": -122.401297,
          "max_lat": 37.788826,
          "max_lon": -122.400826,
          "time": 6.904,
          "length": 0.057,
          "cost": 8.08
        },
        "shape": "shmagAtbwmhFnA`BbAxAjQnV"
      }
    ],
    "summary": {
      "has_time_restrictions": false,
      "has_toll": false,
      "has_highway": false,
      "has_ferry": false,
      "min_lat": 37.788458,
      "min_lon": -122.401297,
      "max_lat": 37.788826,
      "max_lon": -122.400826,
      "time": 6.904,
      "length": 0.057,
      "cost": 8.08
    },
    "status_message": "Found route between points",
    "status": 0,
    "units": "kilometers",
    "language": "en-US"
  }
}

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

Reference: Valhalla map matching API reference