The expressway cut travel time to Galle from the capital Colombo to less than one hour from over three hours by road.
"Now tourists are going from Colombo to have dinner in Unawatuna, and hotels in the area are full," minister Abeywardene said.
Unawatuna is a tourist beach area operated by Sri Lanka's small and medium sector of the industry dotted with small hotels, beach restaurants, bars, shops and discos with a so-called 'happening atmosphere'.
The government recently bulldozed several small tourist projects near the beach.
Minister Abeywardene said action had only been taken against illegal constructions and even then building which were at least a little distance away from the beach had been left standing even though they were within a prohibited area.
Sri Lanka welcomed 850,000 tourists in 2011, up 30 percent but the industry received a blow on December 25, when a group including a local politician connected to the islands ruling party murdered a British tourist and badly