Umferð (Traffic) — Vegagerðin

Real-time traffic counter data from the Icelandic Road Administration via GeoServer WFS.

API

Base URL: https://gagnaveita.vegagerdin.is/geoserver/gis/ows?

No authentication required. WFS 1.0.0 protocol. Returns GeoJSON, CSV, GML, or Shapefile.

Layers

Layer	Features	Description
gis:umferdvika_2021_1	~254	Real-time counters: 15-min count, today's count, rolling 7-day daily totals
gis:umf_talningar_stefnugreint_stadir	~248	Station metadata with direction, elevation, compass heading

WFS Request Pattern

{base}?service=WFS&version=1.0.0&request=GetFeature&typeName={layer}&outputFormat=application/json&srsName=EPSG:4326

Parameters

Parameter	Values
srsName	EPSG:4326 (WGS84) or EPSG:3057 (ISN93)
outputFormat	application/json, csv, GML2, GML3, shape-zip
cql_filter	e.g. IDSTOD=912 to filter by station
maxFeatures	Limit number of features returned

Example Requests

# All stations as GeoJSON (WGS84)
curl "https://gagnaveita.vegagerdin.is/geoserver/gis/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=gis:umferdvika_2021_1&outputFormat=application/json&srsName=EPSG:4326"

# Single station
curl "https://gagnaveita.vegagerdin.is/geoserver/gis/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=gis:umferdvika_2021_1&cql_filter=IDSTOD=912&outputFormat=application/json&srsName=EPSG:4326"

Real-Time Layer Schema (gis:umferdvika_2021_1)

Field	Type	Description
OBJECTID	INT	Unique per measurement point (direction-specific)
IDSTOD	INT	Station ID (may appear twice for directional stations)
NAFN	STRING	Station name (e.g., "Gufuá", "Dettifoss")
STEFNA	STRING	Direction — see below
UMF_15MIN	INT	Vehicles in last 15 minutes
MEDALHRADI_15MIN	INT	Avg speed km/h last 15 min (only for type 4 classifiers)
UMF_I_DAG	INT	Vehicles since midnight
DAGS_SIDUSTUGAGNA	DATE	Timestamp of latest data received
UMF_DAGUR1..7	INT	Daily vehicle count for last 1..7 days
DAGS_DAGUR1..7	DATE	Date for each of the 7 daily counts
MAELISTOD_TEGUND	INT	Station type (see below)
SHAPE	POINT	Coordinates [lon, lat] in requested SRS

Station Metadata Layer (gis:umf_talningar_stefnugreint_stadir)

Field	Type	Description
IDSTADUR	STRING	Location ID
IDSTOD	INT	Station ID
IDSTEFNA	INT	Direction code
NAFN	STRING	Station name
STEFNA_TXT	STRING	Direction text
NSAV_STEFNA	STRING	Compass code
HAED	INT	Elevation (m)
UMFERD	INT	Latest traffic count
DAGS_UMFERD	DATE	Timestamp of latest count
MEDALHRADI	INT	Average speed (if available)
STAERDARFLOKKUR	STRING	Size class ("all")
MAELISTOD_TEGUND	INT	Station type

Station Types (MAELISTOD_TEGUND)

Code	Type	Description
1	Veðurstöð	Counter co-located with weather station
2	Umferðarteljari	Dedicated traffic counter
4	Umferðargreinir	Traffic classifier (provides speed data)

Direction Field (STEFNA)

• Directional: "Til norðurs", "Frá Þingvöllum", etc.
• Combined: "Samanlögð umferð óháð stefnu" (both directions summed)
• Directional stations have two OBJECTIDs sharing the same IDSTOD

Double-count warning: When aggregating, use either combined records OR directional records, never both.

Key Caveat: No Historical API

The API only provides a rolling 7-day window. There is no endpoint for historical data. To build a time series, you must poll regularly (daily) and accumulate into a local store. The collect subcommand handles this.

Script Usage

# List all counting stations
uv run python scripts/umferd.py stations

# Fetch current real-time snapshot
uv run python scripts/umferd.py snapshot

# Collect rolling 7-day data into history (run daily via cron)
uv run python scripts/umferd.py collect

# Generate HTML traffic report
uv run python scripts/umferd.py report

Data Files

File	Format	Description
data/raw/umferd/stations.csv	CSV	Station metadata with coordinates
data/raw/umferd/snapshot_*.json	GeoJSON	Raw API snapshots
data/processed/umferd_snapshot.csv	CSV	Latest real-time flat data
data/processed/umferd_daily.parquet	Parquet	Accumulated daily history (append + dedup)
reports/umferd-traffic.html	HTML	Self-contained traffic report

Other Caveats

• Encoding. GeoServer WFS returns UTF-8 GeoJSON. Station names contain Icelandic chars (Þingvellir, Hvalfjörður, Mývatn, Sólheimasandur); direction labels combine spatial Icelandic (Til norðurs, Frá Reykjavík). Read with httpx.json() defaults; write CSV with encoding="utf-8".
• Rate-limiting. No declared rate limit on gagnaveita.vegagerdin.is. Intended cadence is one snapshot per quarter-hour (matches the source update interval). A daily collect cron is well within budget.
• Double-counting directional data. A single physical site often emits two rows — one per direction. When summing flows for a region, group by station-id-without-direction or filter on a single STEFNA value.