State Highway 1 has reopend near Levin a crash this morning involving a truck and trailer.
Police suggest motorists still consider delaying their travel, given there may be delays in the area.
The road was closed earlier this morning after the crash and rail services were also suspended as the truck was left precariously near the tracks.
By the time one lane was opened later in the morning, traffic had backed up more than 4km in both directions, almost to Levin in the north and to Otaki in the south.