Is the invention of a new means of transport which is a special Sign of the advent of the Promised Messiah. As is written in the Holy Quran:
Meaning that, the Latter Days are those when she-camels will become obsolete. Similarly, there is a hadith in Sahih Muslim that:
Meaning that, in that age ‘she-camels will become useless and no one will travel on them.’ During the days of the Hajj, the journey between Makkah and Madinah is undertaken on she-camels, but the day is close at hand when railways will be constructed for this journey and then it will be true for this journey that 
[She-camels will become useless and no one travels on them.]
1 Surah at-Takwir, 81:5 [Publisher]