Chief Investigator of Accidents, Captain Tim Burfoot, said it was very likely the truck did not stop at the stop signs.
"The truck entered the crossing at about 48km/h and the train struck it at over 60," Burfoot said.
The commission found that even if the truck had stopped, the view was insufficient for driver the truck to clear the level crossing from a stop if a train had been just out of view.
"Level crossing designers consider sighting distances for road users when determining what protection a crossing needs – like barriers and bells or just signage - but growth in vegetation can quickly change sighting distances, making level crossings that were once safe, unsafe."
The commission discovered New Zealand legislation was unclear on the responsibilities of licensed rail access providers and road controlling authorities for ensuring the safety of road and rail users at public road level crossings.
TAIC made four recommendations focused on the long term need to clarify the legislation on responsibility for sight lines in the rail corridor; and the short term need for licensed rail access providers and road controlling authorities to work together to ensure good sight lines at level crossings.
"Whatever happens in terms of responses to the commission's recommendations, road users must always approach railway level crossings with extreme care," Burfoot said.
"Particularly those level crossings that just have 'give way' or 'stop' signs.
"And finally, as always, wearing a seatbelt increases the chance of surviving an accident."