GeoJSON Import

When GPS is lost, such as in a subway, points may jump to a different location. Turbo GPX can exclude jumps using the Track Gap feature. Another method is to fill in missing points. You can add points one by one using the edit feature, or you can fill them in by importing a GeoJSON file.

Supported Files and Limitations

Turbo GPX imports GeoJSON files created or distributed externally.

It is intended for line data, such as railways, roads, and sea routes.

File Format

GeoJSON (.geojson / .json)
FeatureCollection format

Supported Geometry

LineString
MultiLineString

The following data is not imported:

Point-only data
Polygon / MultiPolygon-only data
Single geometry that is not a FeatureCollection

GeoJSON is JSON that describes points, lines, and areas (locations and shapes) in a machine-readable format.

File Size

GeoJSON files larger than 1024 KB cannot be imported
If the amount of data is large, processing may take time

Data Correction and Conversion

During import, the following processing may be applied:

Trimming line data (for example, by station)
Snapping Point data to lines (using a distance setting)
Writing attribute information such as station names to Label / Description
Normalizing time and numeric information

These operations are applied automatically according to the settings.

When Import Fails

GeoJSON Import stops without loading the file if the content does not match the specification.

Typical cases:

No supported geometry is included
Coordinate arrays are empty or invalid
The data structure does not follow the GeoJSON specification
The file size exceeds the limit

In these cases, an error message is displayed.

Options

Settings are available on the [Option] tab of the map window.

Item	Description
Distance	Allowed snap distance from point to line
Trim	Cut out only the required section
Set Start/End Pins	Place pins at the start and end
Set Name to	Destination for the name

For example, when importing a railway route, station points and railway lines may not match exactly. Specify the acceptable range using Distance. When Trim is enabled and start / end stations are specified, sections outside the start-to-end range are excluded. When Set Start/End Pins is enabled, pins are placed at the start and end locations.

Notes

Not all GeoJSON attributes (properties) are reflected
Line direction and splitting depend on the source data
Imported results can be edited and adjusted later

GeoJSON and GPX Comparison

Viewpoint	GeoJSON	GPX
Purpose	General geographic data (points, lines, areas)	GPS logs, mainly tracks
Data representation	JSON (FeatureCollection / Feature)	XML (gpx / trk / trkpt)
Shape	Point / LineString / Polygon, etc.	Track / Route / Waypoint (mainly point sequences)
Attributes / properties	Can freely store values in `properties`	`name` / `desc`, etc. plus extensions
Time	Optional (not required)	Usually stored as `time` in `trkpt`
Elevation	Optional (stored as an attribute)	`ele` is defined as a standard element
Main usage	GIS, map drawing, roads, railways, boundaries	Running, hiking, and cycling logs

Creating GeoJSON

Access the overpass turbo site (https://overpass-turbo.eu/).

Enter the following query and click [Run].

[out:json][timeout:60];

area["name"="Roma"]["boundary"="administrative"]->.a;

(
  node(area.a)["railway"="station"]["name"="Ottaviano"];
  node(area.a)["railway"="station"]["name"="Manzoni"];

)->.stations;

rel(area.a)["route"="subway"]["ref"="A"]->.r;
way(r.r)->.tracks;

(.stations; .tracks;);
out geom;

Select GeoJSON from [Export].

Import GeoJSON