The markers on the map denote Citibike Stations. Their opacity represents the number of bikes currently available at the stations - the more opaque the marker, the more bikes are currently docked there.
Click on a marker to bring up info on a station - this info is shown on the sidebar. This is your starting dock.
Click on a second marker to bring up info on a second station, shown below the first station's info. This is the destination dock.
Based on current and historical data, the planner will give you a recommendation on how likely you will be able to get a bike at the starting station and to dock at the destination station within the hour.
Use the dropdown menu on the side-bar to view historical data from a specified time
The play button will continuously loop through all historical data
The pause button will stop the loop so that you may get a closer look at historical data