If you are traveling to any beach in Costa Rica, it is better to rent a 4WD car. Usually, car rentals don’t have any hand controls, but Service Car Rental offers different options like mini vans, ramps and portable handicap driving hand controls. You have to make a reservation in advance so they can prepare the best service possible.
The fastest way to get to Guanacaste is taking the Route 27 (try to avoid rush hours here) and then Route 1. You will see a lot of green on the journey; trees both sides the road and some good restaurants. See Costa Rica Travel Tips.
The bus service is supposed to be totally accessible, but some of the platforms to get in and out of the bus are not in the best shape. Also, there is little information on the rounds and schedules, almost no bus stop is built under universal design lineaments and very few sidewalks have good accessible conditions. There are also handicap taxis, but this is a usually a more expensive service. You can call to any red taxi service and they have some units available with ramps. The phone number is (506) 2666 2000.