This is the ruling for travelling to holy city lets say to do umrah
http://www.islam-qa.com/index.php?re...txt=travelling
As you can see -- you still need a mahram. There is no excuses akhi --- If you have a mahram you must not travel without one.
And here also
http://www.islam-qa.com/index.php?re...txt=travelling
and here again for women travelling with other women
http://www.islam-qa.com/index.php?re...txt=travelling
InshaAllah this clarifies things for you.
