According to two reasons Katunayake is important to the country of Srilanka.

the main reason is The International Airport of Colombo is situated in Katunayake.

the second reason is the main industrial zone of the country  'Katunayake free trade zone' is situated in Katunayake.

                however there are about 26 km to the border of Colombo From Katunayake.there are two main routs you can reach Colombo.the Colombo -Katunayake express way [ 20 minutes] and A 3 road.[30 minutes to 01 hour].