The public bus system in Costa Rica offers many routes and guests can travel inexpensively and safely aboard these vehicles. Recent rules have mandated the updating of buses so most are comfortable and attractive. Tickets can be purchased in advance and can be picked up at Alajuela, just a few minutes from the airport. This is the hub of the public transportation system and your starting point for most destinations.
 
Several car rental options are available at San Jose International Airport, including Hertz, Budget, National, Adobe, and Europcar. You may find that some of the roads are a bit difficult to navigate by car. Be sure to have a map on hand and avoid driving at night if possible. No international license is needed.

A great option is shuttle service, they can offer to pick you up at your hotel or any departure point pre  shcedule and take you to your destination. Please remember that the shuttle service pick up other clients and that you might do several stops for those pick ups, in every shuttle service you will have  regular stop for lunch. snack or dinner depending on the time.

A less-affordable but convenient option is to fly from one part of the country to another. Airstrips, even in remote areas, are available to accommodate small charter flights. This is a great option for those who might have difficulty tolerating an 8-10 hour bus ride or prefer not to drive in a foreign country.