Officials insist they need to step up efforts to crack down on ride-hailing apps to bring order to public transport services for the sake of passenger safety and interests.
Meanwhile, California-based Uber is calling for a legal amendment to better enable its service in Thailand.
The company opened a bilingual petition page on its website for Thais to sign. It urges the government to amend the law to account for app-based rides.
As of early Friday it claimed to have more than 15,000 signatures, and was aiming for 20,000.
Starting in Chiang Mai last week, the provincial land transport office has been pursuing tougher measures to crack down on illegal ride-hailing taxi services, including Uber and Grab Car. The officials pretended to be passengers and called the cars via their apps. The drivers were arrested and fined when they arrived on request.
Later in Bangkok, officials adopted the same strategy to lure illegal ride-hailing cars, whose drivers were arrested. At least 23 drivers were arrested as of Thursday.
Department of Land Transport (DLT) chief, Sanit Phromwong, said Thursday the department does not bar the use of apps for the taxi service but it cannot allow the adoption of technology to hail a personal car as a taxi service, as this violates the Vehicle Act.
By law, those who want to operate a taxi must have a public transport driving licence and their cars must be registered as taxis.
Drivers have to pass a criminal record check and their profiles have to be kept in the department's database, Mr Sanit said.
"All of these measures are aimed at protecting passengers from unwanted incidents and offences," he said. "But none of those drivers who are operating the illegal taxi services was verified by such procedures."
Mr Sanit admitted there are some drivers of conventional taxis who provide poor service and offend passengers. Officials have made all-out efforts to tackle these problems.
Drivers who are found guilty will be given the maximum punishment, which is usually a fine.
The department is willing to support new technology for taxi services if it is done under a legal framework. For example, Grab Taxi and All Thai Taxi are legal ride-hailing taxi services supported by the department, he said.
In addition, new facilities include the installation of GPS tracking, security cameras, an emergency button linking to the department's centre and a speeding control system which are being used to upgrade taxi standards under the Taxi-OK project.
The DLT's deputy chief, Nanthaphong Choetchu, said there is no need to exercise Section 44 to handle illegal taxis.
"We will arrest more of them," Mr Nanthaphong vowed, saying the close watch on them will continue.
He said the department has been told some people are spreading information allegedly to damage the images of public vehicles, especially registered taxis, to encourage people to use illegal ones.
He admitted that passengers have been long been dissatisfied with poor services including being rejected by registered taxi drivers.
But most of the more than 100,000 taxis listed with the department give good services, he said.
He added that the department takes the passenger complaints seriously.
In response, Uber on Thursday requested a legal amendment to help along its service.
"Since we arrived in Thailand in 2014, Uber has engaged with the department to clarify that we are not a taxi service. There are currently no existing regulations that recognise ridesharing services provided by smartphone applications. The technology that enables ridesharing is different from existing public transportation, which is why we cannot register as public transportation," it said.
"We are committed to continuing dialogue with the department authorities to explain what Uber is, but we believe it is time to amend the legal framework to accommodate this much needed new technology and realise the full benefits it is bringing to riders, drivers and cities."