Here's an article from the Oct 13/14 edition of the Bangkok Post announcing an increase in taxi fares starting in December 2014.
Taxi fares to rise by 8-13%
Published: 18/10/2014 at 12:43 PM
Online news:
Taxi fares will be raised by 8% on average starting in December, with a 13% maximum increase from current levels to come six months later if service quality is satisfactory.
Transport Minister Prajin Juntong said the increases would come in two phases. From December to May, the hikes will be limited to 8%. After the period ends, service quality will be evaluated. If the results are satisfactory, the ministry will allow for increases to a maximum of 13%, he said.
The starting fare of the first kilometre, however, will be capped at the same rate of 35 baht as it has been for more than 20 years.
A 0.50-baht increase to two baht will apply to each subsequent kilometre and when the car stops.
The distance to be calculated will also be reduced to every 10km from 12km, resulting in lower fares for shorter distances.
At present, taxi fares are 35 baht for 0-1km, five baht each for the first to 12th kilometres, 5.50 baht each for the 12th to 20th kilometres, six baht each for the 20th to 40th kilometres, 6.50 baht for the 40th to 60th kilometres, 7.50 baht each for the 60th to 80th kilometres, and 8.50 baht each for the 80th kilometre or higher.
Inflation finally hits the taxi industry - but it will still be fairly inexpensive compared to most countries.