How Far Can a Woman Travel without a Mahram?
Question

I know that a woman is not permitted to travel without a Mahram with her. I would like to know what is meant by (traveling) exactly. Where should we start measuring the distance, from the beginning (a place in the desert), or from where?
My father has a farm on Misr-Ismailia way, and he likes us to visit him every so often, this farm is about 75 minutes maximum from home. Is this considered traveling?
Considering that there are many new cities, schools, companies, and farms along the way.
Praise be to Allah.How far can a woman travel without a Mahram?
The authentic Sunnah indicates that it is not permissible for a woman to travel except with a Mahram . This travelling is not defined by a specific distance, as is the case with shortening the prayers or breaking the fast, rather everything that is called travelling, whether it is long or short, is not permitted for a woman unless she has a Mahram with her. 
Al-Bukhari (1729) and Muslim (2391) narrated that Ibn `Abbas (may Allah be pleased with him) said: The Prophet (peace and blessings of Allah be upon him) said: “No woman should travel except with a Mahram.” 
The jurists unanimously agreed that it is prohibited for a woman to travel without a Mahram, except in a few exceptional cases, such as travelling for the obligatory Hajj, for which some of them have permitted a woman to travel with trustworthy companions .
 Ibn Hajar (may Allah have mercy on him) said: “Al-Baghawi said: They did not differ concerning the fact that a woman may not travel for anything but the obligatory Hajj except with a husband or Mahram , except a non-Muslim woman who becomes Muslim in Dar Al-Harb or a female captive who escapes. Others added: or a woman who becomes separated from her group and is found by a trustworthy man, in which case it is permissible for him to accompany her until he brings her back to her group.” (Fat-h Al-Bari, 4/76) 
An-Nawawi (may Allah have mercy on him) said in Sharh Sahih Muslim, explaining that travel in this case is not defined by a specific distance: 
“Everything that is called travelling, it is forbidden for a woman to do without her husband or a Mahram, whether it is three days, two days or one day, or anything else, because of the Hadith of Ibn `Abbas, according to which the Prophet (peace and blessings of Allah be upon him) said: “No woman should travel without a Mahram.” This includes everything that is called travel. And Allah knows best.”  
And it says in Fatawa Al-Lajnah Ad-Da`imah (17/339): “It is prohibited for a woman to travel without a Mahram in all cases, whether the journey is long or short.”
Based on this, if going from your city to this place is regarded as travelling according to the people`s customs, then it is not permissible for you to go there without a Mahram. If it is not regarded as travelling according to custom then there is nothing wrong with you going there without a Mahram. 
The fact that the route is filled with cities, schools and farms does not alter this ruling. 
Minimum distance for breaking fast and shortening prayers
With regard to shortening the prayer or breaking the fast when travelling , and wiping over the Khuffayn for three days and nights, the majority (of scholars) are of the view that travel in this case is defined by a certain distance, which is approximately 80 kilometers , and that distance starts from where the built-up area of the city ends. (See, Tuhfat Al-Muhtaj, 2/370 and Al-Mawsu`ah Al-Fiqhiyyah, 27/270). Some scholars do not define it by a particular distance, rather they refer the matter to local customs. 
And Allah knows best.