Service accessibility analysis over road networks

Example: Analysis of accessibility to critical services (hospitals, schools, emergency facilities) using road network data and travel time calculations.

Step-by-step guidance

1. Dataset-level metadata

Select the following values when describing your dataset:

  • Risk data type: exposure

  • Title: “Service accessibility analysis for [region]”

  • Description: Brief description of the accessibility analysis, services included, and methodology (e.g., network analysis, isochrones)

  • Publisher: Organization that performed the accessibility analysis

  • License: Appropriate license

2. Resources

Add resources for your accessibility analysis files:

  • Format: shapefile, geopackage, geojson, csv, or geotiff

  • Spatial resolution: Network segments, grid cells, or point-based (service locations)

  • Coordinate reference system: EPSG:4326 or appropriate projected CRS

You may have multiple resources for:

  • Road network data

  • Service locations (points)

  • Accessibility zones (isochrones or travel time grids)

  • Summary statistics by administrative area

3. Exposure metadata

Under the Exposure section:

Category

  • Category: infrastructure

Taxonomy

  • Source: Custom or infrastructure classification system

  • Codes: Specify service types (e.g., healthcare, education, emergency response)

Metrics

Define what is being measured:

Metric 1 - Travel time:

  • Dimension: accessibility

  • Quantity kind: time

  • Unit: minutes or seconds

Metric 2 - Distance (optional):

  • Dimension: accessibility

  • Quantity kind: length

  • Unit: km or m

Metric 3 - Service capacity (optional):

  • Dimension: structure

  • Quantity kind: count

  • Unit: 1 (e.g., number of beds, classrooms)

Occupancy

Specify infrastructure types:

  • healthcare

  • education

  • emergency_services

  • transportation

  • (Select all that apply)

4. Spatial coverage

Define the geographic extent:

  • Scale: sub-national, national, or regional

  • Countries: Select applicable ISO 3166-1 alpha-3 country codes

  • Administrative regions: Specify provinces/districts if relevant

  • Bounding box: Specify coordinates of the analysis area

Example data structure

Your accessibility dataset should include:

Service locations:

  • Service ID

  • Service type/category

  • Coordinates

  • Capacity information

  • Operating status

Road network:

  • Road segment ID

  • Road class/type

  • Speed limit or average travel speed

  • Road condition

  • Geometry (line)

Accessibility results:

  • Location identifier

  • Nearest service ID

  • Travel time (minutes)

  • Travel distance (km)

  • Service accessibility category (e.g., “within 30 minutes”)

Key considerations

  • Specify the travel mode assumed (driving, walking, public transport)

  • Document assumptions about travel speeds and road conditions

  • Include temporal factors if relevant (peak hours, seasonal access)

  • Clarify whether analysis considers barriers (bridges out, flooding, etc.)

  • Reference the road network dataset used (e.g., OpenStreetMap, national road database)

  • Specify the method used for accessibility calculation (network analysis, Euclidean distance, cost-distance)