Towards the end of the 19th century, many surveys were commissioned by the Siamese authorities and certain western interest groups and governments, with the object of bringing a railway system to Thailand.
One of the best known of these was the survey conducted by Holt S. Hallett, a British colonial administrator, whose object was to promote a railway line to take British goods from the Gulf of Martaban (Burma), through what was then Siam, to Southern China. His superb book: A Thousand Miles on an Elephant in the Shan States, first published in 1890 and still an excellent source of information on Northern Thailand, was the main result of this journey: the railway, alas, was never constructed.
Then in 1887-1888, Messrs Punchard and Co., British Railway Contractors, were commissioned by the Siamese government, to survey a line from Bangkok to Ayutthaya and then to Korat, the first section of the current North Eastern Line. James McCarthy, a British engineer employed by the government of Siam, describes some of this work in his book Surveying and Exploring in Siam, first published in 1900.
A second line was to go from Ayutthaya to Lopburi, then on to Lampang, Lamphun and Chiang Mai. From Chiang Mai it was projected to go north to Chiang Rai and eventually to Chiang Saen on the Mae Khong (Mekong river).
Much of this survey bore fruit, some years later, in the construction of parts of the northern and north-eastern lines though the section of the northern line beyond Chiang Mai has not been constructed, even to this day: the connection north to China via Chiang Saen and the Mae Khong, was very attractive from a trade point of view, but the engineering difficulties presented by the mountains of northern Thailand proved too daunting.
A recent (March 2010) proposal from the Chinese Government, however, for a high speed link between Asia and Europe might at last result the long overdue rail link from Thailand to Southern China.