They issued the warning at a meeting of the House committee on entertainment reform held earlier this week.
The government has announced that nightspots in Bangkok, Chiang Mai, Chonburi and Phuket will be allowed to stay open until 4am in a pilot project to boost tourism.
However, the move’s opponents cited data showing 2,118 people were killed in drunk-driving accidents in the four provinces alone last year, causing damage worth over 6.5 billion baht.
The data was produced by Thanapong Jinwong, manager of the Centre for Road Safety.
He said drunk-driving killed 1,004 people in Bangkok alone last year.
Most fatal drunk-driving accidents occurred in nighttime hours up to 3am, he added.
In that scenario, students, vendors, and monks who are on the streets during the early morning could be killed by drunks behind the wheel, he said.
Statistics also showed that foreign tourists were victims of drunk-driving accidents. In Phuket alone, over 3,461 foreign tourists were injured or killed by drunk driving last year, he said.
Extending pub hours could damage rather than boost tourism, Thanapong warned.
Thaejing Siripanit, secretary-general of the Don’t Drive Drunk Foundation, said motorists were not afraid to drive while drunk because they knew they could bribe police if caught.
He said drunk drivers often evaded serious charges such as driving with awareness they could cause fatal accidents, and were let off with suspended jail sentences.
Jessada Yaemsabai, head of a network of drunk driving victims, said he himself was badly injured by a drunk driver at 2am, which had brought a heavy impact on his family.
Despite his network’s active campaigning against drunk driving, drinkers were still not afraid of the law and related businesses were not taking responsibility for the impact on society, he said.
He complained that police do not set up enough checkpoints on roads and that more innocent Thais and foreign tourists would inevitably fall victim to drunk drivers.