Chiang Mai Municipality began work in December 2004 as part of a strategy to improve the appearance of Tha Pae and Chang Klan roads, both popular tourist areas.

But critics claim Tha Pae Road has been left with a deteriorating surface, while there has been a rise in air pollution and traffic congestion. Neighbouring buildings, temples and pagodas have had problems of structural cracking as a result of the work.

Deputy Mayor Poonsawas Worawan said construction had been delayed by last year's flooding, which caused sand to enter cavities. He said the scheme was 80-per-cent complete and pledged all construction of cavities, roads and footpaths would be finished by September 15.

Residents will have to bear further disruption when the Electricity Generating Office and Telephone Organisation of Thailand move wires underground and remove posts from the streets.