The Commission found that the train would have been visible to the Hamilton driver had he looked, but there were "broader safety issues with the level crossing".
The train's headlights and side lights were on at the time, and the driver applied emergency braking and sounded the horn.
But the view lines from the stop line at the crossing did not comply with minimum standards, so when a train was just out of the driver's view, a heavy road vehicle would not have enough time to pass over the level crossing "without being struck by the train".
But the Commission found that Mr Clements did not stop, causing the accident.
Level crossings are not routinely checked, the commission said.
TAIC recommended the NZTA address these safety issues.
The report also warned drivers to comply with stop signs at level crossings and check for trains.