Now I don’t want to worry you, but it’s no secret that Portuguese drivers aren’t the best in the world. However, they are not the worst either. Driving in the cities can seem chaotic, with motorists not taking much notice of such things as line markings; while some stretches of motorway are quite notorious as white-knuckle rides. Just take care, expect the unexpected, and experienced drivers should adapt in no time.
Overall the roads are very good. You can travel the country from north to south on modern motorways serving all the major cities. Most of these are toll roads, so make sure you have change or credit/debit cards handy.
The government is working hard to improve road safety. Laws have changed recently to bring in severe penalties for speeding, driving under the influence of drink or drugs, driving without a licence, etc. Many roads have cameras keeping an eye on the traffic and there’s plenty of signage telling you want you can’t do.
So, maybe it’s best to give it a test run — outside of the rush hour periods — to see if you have a taste for it. And remember, if you are doing it properly you should be driving on the right!