Outside of San Jose a private vehicle can be very convenient. In San Jose, you may find that parking and traffic jams make having a car more of a headache than it is worth.
If the hotel you were planning on staying in misplaces your reservation, you can hop in your car and go few miles down the road, confident that in a short time you will run across another place to stay. If you are traveling by bus, then once you get to your destination you will probably be on foot, and a few miles down the road is a long way to walk.
Speed and Efficiency
When traffic is light and the roads are good, a car can be a quick way to get around, but don't think you are going to average 60 MPH. The roads are narrow, and many wind steeply through volcanic valleys. At times you will end up stuck behind a cattle truck going five miles an hour down the center line for an hour or more. The rain is tough on the roads and construction and repair will also often delay you. On a few occasions, we passed long lines of cars on our bicycles, much to the frustration of the drivers. A good number to use to estimate average travel times is 45 kph (that's kilometers per hour, or 28 MPH).
A rental car costs a lot if you're on your own, but for a group of three or four who want to visit a lot of locations it can compare favorably with the price of the bus. For example, an inexpensive four-passenger sedan can be had for $US 270 a week (including unlimited free mileage, taxes and mandatory Collision and Damage Waiver insurance). In mid 2005 gasoline cost aprx. $US 4.00 a gallon.
Driving at night is not recommended
It is dangerous because of the high percentage of other drivers who have been drinking, the inability to see potholes in the dark, precipitous drop-offs without guardrails, and because you will miss all of the scenery. Another danger entered the scene in 2004, car jacking or robacarros and bajonazos who strike almost exclusively after dark.
Do not leave anything of value in your car
Not even for a minute and especially not in the locked trunk. It will probably be stolen, and you may be responsible for the damage the thieves do getting it out.
Stay off the area just above high tide line
Driving is allowed on some Costa Rican beaches, but please avoid the sand between the high tide mark and the trees because this is where the sea turtles make their nests.
Don't count on road signs for navigation
Although the situation is slowly improving there are very few. Get a good map and ask directions early and often.
Drivers and Driving Accidents
Drivers should carry their passport as well as driver’s license. In the event of an accident, call the police immediately to make a report at 117 (required for insurance purposes) or attend to any injured parties. Leave the vehicles in place until the report has been made and do not make any statements except to members of law-enforcement agencies. Injured people should only be moved by medical professionals.
Keep your eye on your vehicule until the police arrive and then call the car-rental company to find out where you should take the vehicle for repairs.