The Thailand Consumers' Council (TCC) has asked the government to lower ticket fares for Bangkok's trains and keep them at under 10% of the daily minimum wage, equal to about 33 baht per round-trip.
Saree Aongsomwang, secretary-general of the newly established consumer protection body, said the cost of public transport in Bangkok had become too expensive for many travellers and it was deterring people from using it.
She cited the case of the BTS Green Line, whose new fares mean commuters would have to pay more than 100 baht to travel on the whole route.
"The price is unacceptable when compared with the daily minimum wage of 331 baht per day -- lower-income people can't afford the electric train service," she said.
"Mass transit in Bangkok has become a rich man's toy, not a real mass-transit system."
In response to the Bangkok governor's latest decision to indefinitely postpone BTS Green fare hikes, Ms Saree said that was no more than a piecemeal effort.
"The government should set up a committee responsible for setting fair prices for the whole electric railway system, covering at least 14 lines in the future," she said.
The TCC on Tuesday asked the government to impose a 15-baht flat rate for the entire length of the Green Line, and thus rejig concessionary fares to be fairer to everyone.
Apart from investing money to build more city train systems, the authorities should also focus on restructuring city train fares, said Ms Saree.
She said other cities' train fares were less of a burden on travellers, citing figures prepared by the Thailand Development Research Institute to illustrate that urban train fares were lower in Paris (5% of the daily minimum wage), Tokyo (9%) and Chinese cities (3.1%).
Bangkok governor Aswin Kwanmuang on Tuesday signed the order indefinitely delaying the controversial Green Line fare hikes, following the cabinet's suggestion that they be reviewed.
The BMA last month announced a maximum Green Line fare of 104 baht, due to come into effect on Jan 15. The new fares were initially scheduled to come into effect in February last year.