In order to use the system, users need to take out a subscription, which allows the subscriber an unlimited number of rentals under 30 minutes for 1 day and 3 days subscriptions, and 45 minutes for 1 month and 1 year subscriptions. A trip that lasts longer than this no-charge time period gets additional charges, on an increasing price scale. The increasing price scale is meant to keep the bikes in circulation. Subscriptions can be purchased at $7 per day, $15 for 3 days (at a pay station only), $30,25 per month or $80,50 per year.