This visualization shows the geographic distribution of alternative fuel stations as of April 4, 2012, using a temporal heat map. The CartoDB Torque library animates the points over ten seconds, aggregating station counts per cell with a linear data aggregation function. The code applies a `colorize-alpha` image filter to markers, transitioning from red through blue based on density, while frame offsets increase marker width and reduce opacity to create a motion trail effect. The map uses static marker images from an Amazon S3 asset and relies on Torque’s time-based rendering to reveal spatial clustering over time.