The Unwritten Rules of the Costa Rican Roads
Three of the most important differences you should know:
1. Just like in the US, rolling stops are illegal. However in recorded history no one has been cited for a rolling stop in Costa Rica. A rolling stop at a stop sign in the US means you may get a ticket. A full stop at a stop sign in Costa Rica means you may get rear-ended.
2. In the US, passing on a blind curve is a sin. In Costa Rica not letting somebody in who passes on a blind curve may be a mortal sin. When you see a big slow truck in the oncoming lane, be ready for the guy behind him to be passing him -- and the woman behind you to be passing you.
3. Understand that driving in the US and driving in Costa Rica stem from vastly different cultural traditions. Driving in the US is derived from the lore of the Old West. There may be a veneer of courtesy, but down deep it is the showdown at high noon. If you back down your very manhood has been compromised - womanhood too. Hence road rage.
Driving in Costa Rica on the other hand is inspired by the ancient tradition of the bullfight. How close can you get without getting hurt? The driver who cuts you off in Costa Rica is not insulting you. He´s playing with you. Your role in the game is to not get cut off, as long as nobody gets hurt. Hence everybody tailgates.
The best way for you to handle this is the same as for newcomers to all games: play, but play by local rules; don´t play too intensely; and expect to lose. Defensive driving at all times is the key.
It is important that you understand that the rules and policies regarding car rental in Costa Rica are even more in favor of the company than they are in the US. Before renting a car in Costa Rica you should make yourself aware of the differences and be sure that they are acceptable to you.