Heatmaps allow you to assign color codes to specific addresses, cities or zip codes to let you quickly identify where a trip is going to start and where it will end. This works in conjunction with "Scheduler" mode to help you quickly assign your trips to the right driver for better efficiency.
To create a Heatmap, go to More > Heatmaps > New Heatmap
If you click on "Scheduler" view, you will now see trips on your board with your heatmaps colors to identify the area that you've set in your heatmaps.
Pete Carroll's trip starts in Tacoma and ends in Seattle so I can quickly see that by the heatmap colors. The color will blend into each other depending on your heatmaps to give you a quick visual to see where are you trips are taking place. Ideally, you want all of the trips for a single driver to stay in the same heatmap "zone" so your colors will "chain together".