To operate a vehicle in Spain, you must possess a stateside driver's license with an official translation, an International Drivers License, or a license from an European Community country. The Spanish Police will periodically stop traffic to check for insurance, proper driver's license, and condition of vehicle. Speed limits are not always posted in Spain. Autopistas are multi-lane toll roads while Autovias are normally free.
Road conditions are usually good.
Liability insurance is required as a minimum for every car driven in Spain. Failure to do so could result in serious consequences. Obtain a copy of the accident report from the police. If the accident is minor, get all the information from the other driver if possible. If you are TDY to Spain, report all motor vehicle mishaps and other incidents to the Security Forces.