I dont know the exact distance. But using the scale ITT gave, in a straight line from Munderra to port, its roughly 115 to 125km away. Keep in mind, roads are NOT in straight lines. So the travelling distance would be more.
Heres a rough guide using a new scale, from ITT's scale:
http://img172.imageshack.us/img172/5201/ittxy4.jpg
