Main Roads WA has confirmed the truck driver responsible for Tuesday morning's crash on the Mitchell Freeway will be forced to pay for all costs relating to the incident, including Hay Street bridge overpass repairs and the debris clean-up.

The truck and its heavy load collided with the bridge at around 9.45am, and brought the freeway to a standstill all the way up to Hutton Street due to concrete debris littering the road.

Large debris was left scattered across the centre lanes. Credit:Melissa Thomas

The freeway was reduced to one lane while Main Roads' bridge inspectors and maintenance crews cleared the debris and assessed the safety of the bridge, and a Main Roads WA spokesperson said the truck driver would be responsible for all costs associated with the accident.

"In the case of today's incident, Main Roads will seek to recover from the truck operator all costs associated with the bridge repairs and the emergency response and clean-up," they said.