Rio Maior in Portugal is relatively safe for solo female travelers. As in any global location, it's essential to remain vigilant, particularly at night or in less crowded areas. However, most locals are friendly and willing to help, and serious crime rates are relatively low. Nonetheless, common travel precautions should still be taken including not displaying valuable items openly, avoiding solitary areas late at night, and using only licensed and reputable transportation services. As always, keeping emergency numbers and contacts at hand is advised.