This example builds a dynamic topographic map from traffic data by buffering and dissolving point geometries into nested contour layers. It first generates a series of buffer rings around each data point, scales the car counts across nine distance levels, and then unions those buffers into isolines representing traffic intensity. The SQL query uses PostGIS functions like `ST_Transform`, `ST_Buffer`, and `ST_Union`, while a second pass outputs the original points. The result combines colored topo bands and overlaid points, with the visualization likely rendered using a web-mapping library that consumes the `the_geom_webmercator` geometries.