driving in Spain

It would be a good idea to have an International Driving Permit. It's basically a translation of your US license into several languages, so that if you are stopped they will be able to see that your license is valid. You can get them at AAA offices, and they cost under $20, I think.

You are required by law to have an IDP.

Thanks, Neil. I didn't know it was actually required in Spain. I have not driven there, only ridden in a friend's car.

Thanks for the good advice!

Yes, IDP required. Pick it up at any AAA office. I think it's $15-20 plus passport photos (bring your own if you have any extras). We drove there all April. I don't recall the car rental agency asking for it, and I wasn't stopped by police, so I probably never "needed" it. If I had been stopped, however, it could have been a minor disaster that would have been cheaply and easily avoidable. Your Washington driver's license is fine but it's worth studying road signage before you go. To the extent you can, use the A - autovias rather than AP - autopistas, they are both great roads. The AP's won't save enough time to justify the toll. The N - national roads work well too but go through towns, rather than around them so you lose some time to stop signs/roundabouts.

Excellent additional tips about driving in Spain. I've been wondering about the various motorways as I study maps in anticipation of our trip. Thanks, this is very helpful!

IDP is required, not by rental agency, but by police if pulled over.
AAA I think still charges $30 inclusive of photos (if you don't have your own). Become familiar with the road signs, especially the ones that are not intuitive: http://en.wikipedia.org/wiki/Comparison_of_European_road_signs When on a freeway, the left lane is for passing only, not for cruising under the speed limit like you people like to do on I-5 up in Washington. Move to the right lanes please and stay there. Europeans are in a hurry and aren't allowed to pass you from the right lanes, like you can in the US, so they have to wait for you to move back to the right lane before they can pass you. They also have little patience, and if you don't move out quickly enough they'll tail gate you aggressively until you do move out of the passing lane. No right turn on a red light either (unless specifically authorized by a green right arrow light).