It may be Capital Bikeshare’s third birthday this weekend, but Michael Schade isn’t celebrating with cake. Instead, he gave riders a map.

Users can select a Bikeshare station from a drop-down list and see a visualization of exactly how long it would take to get to any other station in the system. Stations that are within the 30-minute window when rides are free are marked by green balloons; stations outside the limit are marked with red.

The impetus for the map was mostly Schade’s own curiosity. As Chief Data Visualizer for Mobility Lab, a research and development initiative of Arlington County Commuter Services, he’d had to chart the distances between stations for a separate project and was looking for further uses for that data.

And since “all maps are great,” according Schade, visualizing the time it would take to cover those distances was a natural next step. He plugged the coordinates for Capital Bikeshare’s 248 stations into Google Maps and used an algorithm to chart the 61,256 different routes between them.

“I thought it would be a good tool to see what you could do in 30 min with a CaBi bike,” he says.

Turns out, you can actually do quite a lot. The Lincoln Memorial station, from which riders can make trips to 184 other stations in under 30 minutes, is the most accessible station in the system. Even if a less central station is chosen—say, John McCormack Drive and Michigan Avenue NE in Brookland—about half the map is still covered with green balloons. The longest trip in the system, 15.6 miles from Fessenden Street NW and Wisconsin Avenue NW in Friendship Heights to Benning Road NE and North Capitol Street—takes about 85 minutes.

Schade says that the times estimated by the map are pretty reliable, because the algorithm takes elevation, stop lights, turns and road quality into account when calculating biking speeds. If you want to move fast, try coasting down the hill between 18th Street and Wyoming Avenue NW to the station at California Street NW and Florida Avenue  in Adams Morgan—you’ll hit 18.6 mph. But if you’re thinking about biking between 19th and K and and 19th and L streets in the Farragut Square neighborhood, you’re better off walking, since you’ll only be moving at 1.9 mph.

As for how he thinks riders will be able to use his map, Schade says it’s mostly for fun.

“It’s really just to kind of play with,” he says. “Bikeshare is a fascinating system, and this is just a cool tool to visualize … how it interacts with our city.”