It is generally safe to drive in Portugal, although you should always stay aware of your surroundings and other drivers. People in Portugal tend to be a little aggressive when it comes to overtaking, even if it’s a curve, and they tend to follow extremely close.
Also, while most roads are in good condition, there are smaller roads that are poorly maintained and can be difficult to maneuver if you’re not an experienced driver. However, this shouldn’t deter you from planning a road trip! Just remember that you need to be careful, avoid any distractions, and keep your eyes peeled for unexpected events.