Police said they will limit access to Khao San Road as the well-known street was dangerously overcrowded on Thursday night.
Police temporarily blocked access to Khao San Road at about 7pm on Thursday and told new visitors to wait for people to leave the 400-metre-long road in Phra Nakhon district first.
Police asked visitors to wait about 15 minutes.
At 8.50pm police prevented access to the road and told newcomers to visit nearby Ratchadamnoen Avenue instead.
The deputy national police chief said that police had to impose limits on visits to Khao San Road for public safety.
"For concerns about overcrowding, measures were worked out based on New Year celebrations here. Exits have been prepared for Khao San Road in case of emergency," he said.
He added that Songkran celebrations on Khao San Road were set to end each night at 10pm but visitors would possibly stay later.