You can reserve a bike from the mobile app for up to 10 minutes, so it will be waiting for you when you arrive. This way you’ll never have to worry about showing up to an empty station when you need to get somewhere.
Please note that the amount of time a bike is on reserve for you counts toward your total ride time. If you've purchased a Single Ride and reserve a bike, but aren't able to pick up the bike by the time the 10 minute reservation expires, you will still be charged the $2.50 cost of the ride.
To reserve a bike, click on a station icon or a single bike icon on the map, then press the button that says “Reserve a bike at this hub” (or “Reserve this bike” for single bikes not at a station). If you change your mind, you’ll have one minute to cancel the reservation without the time counting against your account or without facing a $2.50 charge if you’re a Single Ride member.