The driver, Md Hanif, had fled after the accident near Bashundhara City Shopping Complex in Panthapath on Thursday afternoon.
The victim, Ahsan Kabir Khan, the pillion rider of a motorcycle, fell after it was hit by the truck. The truck then ran over him, police said, citing witnesses.
The RAB informed the media about the arrest in a message on Friday night, saying details will be provided on Saturday.
A case has been started at Kalabagan Police Station over the fatal accident, which occurred amid student protests over the death of a peer in a similar accident involving another city corporation garbage truck in Gulistan on Wednesday.
Ahsan had worked at the daily Prothom Alo. He left the newspaper several years ago and joined another media outlet.
The city corporation has formed a three-strong committee to investigate the accident.