Generate the mean travel time to nearest major city — gen_traveltime

Aggregates the high-resolution travel time raster to PRIO-GRID cells and computes the mean travel time within each cell. This is useful for identifying the average travel access to major cities within a PRIO-GRID cell.

Usage

gen_traveltime_mean()

Value

A single-layer SpatRaster object

Details

This function is a convenience wrapper around calc_traveltime using aggregation_function = "mean". It reads the global travel time raster and summarizes each PRIO-GRID cell to the mean travel time value.

References

Nelson (2008). “Travel Time to Major Cities: A Global Map of Accessibility.” 2025-05-14.

Examples

if (FALSE) { # \dontrun{
# Generate mean travel time raster
r <- gen_traveltime_mean()
terra::plot(r, main = "Mean Travel Time to Nearest Major City")

# Extract values for a specific region (e.g., West Africa)
africa_extent <- terra::ext(-20, 20, 0, 20)
r_africa <- terra::crop(r, africa_extent)
terra::plot(r_africa, main = "Mean Travel Time in West Africa")
} # }