Snowflake Public H3 Routing Cache

Use public H3 routing caches in Snowflake with ready-to-map SQL.

How to use these examples#

Install a public H3 routing cache from Snowflake Marketplace, then paste the matching SQL example into a Snowflake worksheet.

The examples use SCHEMA.TABLE names, not DATABASE.SCHEMA.TABLE names. Snowflake Marketplace consumers choose their own database name when installing a listing.

UK H3 Travel Matrix#

The UK H3 Travel Matrix is an origin-destination routing cache for travel analysis in the United Kingdom. Each row represents travel between one origin H3 cell and one destination H3 cell.

The matrix was computed by Snowflake from heavy ground-vehicle routing, not simple straight-line distance or normal passenger-car estimates. Generating country-wide time-distance matrices requires substantial routing compute. This public cache makes the result available for analysis without running the full routing job yourself.

Snowflake’s routing examples show how routing workloads can run inside Snowflake with Snowpark Container Services, including directions, optimization, isochrones, and time-distance matrices. See Build Routing Solution in Snowflake with Snowflake CoCo and the Snowflake Labs route optimization simulator.

Main table:

FLEET_ANALYTICS.UK_H3_TRAVEL_MATRIX

Columns:

Map travel times from London#

This query maps travel time from one London H3 cell to reachable UK destination cells.

-- London H3 cell:
-- SELECT H3_POINT_TO_CELL_STRING(TO_GEOGRAPHY('POINT(-0.1218076741 51.492116613)'), 7);

SELECT
  dest_h3,
  ROUND(travel_time_seconds / 3600.0, 1) AS travel_hours,
  ROUND(travel_distance_meters / 1000.0, 1) AS travel_km,
  ST_X(H3_CELL_TO_POINT(dest_h3)) AS longitude,
  ST_Y(H3_CELL_TO_POINT(dest_h3)) AS latitude
FROM FLEET_ANALYTICS.UK_H3_TRAVEL_MATRIX
WHERE origin_h3 = '87194ad14ffffff'
  AND travel_time_seconds IS NOT NULL;

Use longitude and latitude as point columns in a map. Color by travel_hours to see travel time from London.

Choosing another origin#

Snowflake’s H3 functions can convert a longitude/latitude point into an H3 cell:

SELECT H3_POINT_TO_CELL_STRING(TO_GEOGRAPHY('POINT(-0.1218076741 51.492116613)'), 7);

For repeated queries, calculate the H3 cell once and paste the literal value into the WHERE origin_h3 = ... filter. This helps Snowflake prune the table efficiently.

Query patterns#

Travel time from one origin to all reachable destinations:

SELECT *
FROM FLEET_ANALYTICS.UK_H3_TRAVEL_MATRIX
WHERE origin_h3 = '87194ad14ffffff'
  AND travel_time_seconds IS NOT NULL;

Travel time to one destination from many origins:

SELECT
  origin_h3,
  ROUND(travel_time_seconds / 3600.0, 1) AS travel_hours,
  ST_X(H3_CELL_TO_POINT(origin_h3)) AS longitude,
  ST_Y(H3_CELL_TO_POINT(origin_h3)) AS latitude
FROM FLEET_ANALYTICS.UK_H3_TRAVEL_MATRIX
WHERE dest_h3 = '87194ad14ffffff'
  AND travel_time_seconds IS NOT NULL;

Performance notes#

The UK H3 Travel Matrix table is clustered by ORIGIN_H3, so origin-based lookups are the fastest path. Prefer a literal H3 value in filters instead of calculating it inline for every query.

For exploratory maps, start with one origin or one destination cell. Full-table scans over all origin-destination pairs can be expensive.

See also#

• Snowflake H3 function reference
• Snowflake Kepler.gl map examples

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