To walk in isolated places whether in town or country is unsafe for anyone, not just women.
Having said that I think the danger is much less in the country where the myriad of footpaths that crisscross the countryside are only known to local people and in some places impassable.
I walk all the footpaths in my village alone and without a dog and never feel unsafe. All sorts of horrible things can happen to anybody anywhere, but in most cases exceptionally rarely, which is why such cases hit the headlines. If you are terrified of going anywhere that might be dangerous, then you would spend your life in bed, and who can say you are safe there? before dying of a coronary embolism caused by lack of exercise and movement.
Everyone needs to learn how to assess risk and make rational decisions based on the real statistical risk and not just based on stories that it could be damgerous if you walked somewhere at midnight on the night of the full moon when the zombies and ghouls are out at play.