In the incident yesterday morning, all 39 other passengers, as well as the drivers of the two heavy vehicles, escaped with minor injuries.
Selangor Fire and Rescue Department director Norazam Khamis said in the 3.30am mishap, the bus was believed to have crashed into the back of the trailer travelling in the same direction.
He said the woman, Hamaizah Fadzilah, 54, was in the front seat and the most affected by the frontal impact of the collision.
“She was pinned to her seat and we managed to get her out at 5.13am, but she was pronounced dead at the scene,” he told Bernama.
The cause of the accident is still being investigated, he added. The body of the victim was taken to Kuala Kubu Bharu Hospital for a post-mortem.
Highway users with information on the accident are urged to contact the police to help in investigations.