In 1973, the consulting firm, TAMS Engineering, conducted a preliminary feasibility study on the Kra Canal project and had made the following route proposals (cf. map below).
TAMS had concluded at the end of their study that Route 5 A passing through from Songkhla province on the coast of the Gulf of Thailand to Satun province on the coast of the Andaman Sea was indeed the best route backed by reasons to be found in the table below.
The National Economic and Social Development Board (NESDB) has proposed that a study be conducted on the Land Bridge passing through Route 3 A, which stretches from Krabi to Suratthani. There is already an existing road between these two provinces acting as a land bridge. However, there has been no investment, as of yet, in the building of an oil pipeline between the two coasts. The Ad hoc Committee of the Senate to Conduct the Feasibility Study of the Kra Canal Project was created on May 17, 2001 and was presided by Mr. Kamnuan Chalopatham. They were assigned to conduct a pre-feasibility study of the Kra Canal Project. The study took three years and on May 11, 2004, the Ad hoc Committee reported their findings to the Senate and the National Committee.
The Ad hoc Committee of the Senate announced the following considerations:
1. Thailand should build the Kra Canal to develop the Thai economy.
2. The Ad hoc Committee is of the opinion that it is not worth investing in the Land Bridge.
3. Route 9 A was favoured because it passed through many southern provinces such as Krabi, Trang, Patthalung, Songkhla and Nakorn Srithammarat. The canal would be approximately 120 kilometres in length.
4. It was suggested that Special Economic Zones be developed along the canal on both sides and would be of greatest benefit to the five provinces bordering the canal.
5. It was proposed that a deep sea port be built in the province of Nakorn Srithammarat on the side of the Gulf of Thailand and in Krabi on the side of the Andaman Sea.
6. Areas along Route 9 A must be explored and information teams were sent out ten times to inform the general population in the area about the Kra Canal project.
7. Geographic Information Systems (GIS) must be used to re-position Route 9 A as can be seen in the map on the scale of 1 : 50,000.
8. From on-site investigative studies covering five provinces as well as conferences that took place in the various provinces, it was found that out of 155 persons polled, 78.1% already knew about the Kra Canal, 93.5% were in favour of building the Kra Canal (145 persons out of 155), 81.9 % said the Kra Canal would mean the creation of a new international sea lane of communication.
9. The Ad hoc Committee also studied information concerning the impact on the environment and the density of population in the area. The Ad hoc Committee then concluded that Route 9 A would negatively impact area the least. The Kra Canal would be 30 meters deep, approximately 120 – 125 kilometres in length and 350 meter wide.