All perfect praise be to Allah. May His blessings and peace be upon our Prophet Mohammad.
The Shafite Scholars laid down conditions for using the concessions granted to a traveler such as: travel must be for a reason, so one who travels merely for cruising across countries and for tourism isn`t allowed to shorten the prayer.
On the other hand, if the travel was for a reason such as trading, and the traveler took a certain route for picnicking, seeking safety or visiting a relative, then he is allowed to make use of the concessions granted to a traveler because, in principle, his travel is for trading and picnicking comes with it. This issue was stated by the Shafites when they discussed whether his destination was reachable through two routes, one is short and the other is long, so if he took the long one for a reason like picnicking, then he is allowed to shorten the prayer, or else he isn`t.
Al-Khateeb Ashirbini said: “If it was said: how could he shorten the prayer while the aim is picnicking although they are saying: If he travels to see a country, he isn`t allowed to shorten the prayer. My answer is: Picnicking here isn`t the reason for travelling, but the reason is a sound one such as travelling for trading, but he opted for taking the longest of the two routes for picnicking contrary to just seeing the country which is the reason for travelling. ” {Moghni Al-Mohtajj vol.1 pp.523) }. And Allah Knows Best.