Rail safety systems 'have to evolve' as concerns raised over trains running red lights

The Transport Accident Investigation Commission has named trains running red lights as one of its top concerns.

Chief Commissioner David Clarke said the rising number of "signals passed at danger" had made it onto the agency's annual watchlist, which monitors the sector's biggest safety concerns.

"That's a train passing through a red light, in simple terms. We've seen an increase in notifications and accidents involving those sorts of incidents," he said.

"In fact, in the last three to four years we've seen four that involved passenger trains."

KiwiRail's 'SPAD' rate had doubled between 2020 and 2025, up to 3.2 incidents for every million kilometres.

That's more than triple the benchmark of one incident per million kilometres.

"As rail is evolving it's getting busier, there's more freight and passenger traffic, and as the extent of the traffic on the network increases, that increases risk. The safety systems have to be reviewed and have to evolve," Clarke said.

He said some parts of the network had engineered protections against SPADs, but not all.

"For example, in Wellington if a signal's passed at danger a mechanical lever on the side of the rail will trigger the emergency brakes," he said.

"But much of the New Zealand rail network doesn't have those engineering controls and relies on locomotive engineers seeing and reacting to signals."

Clarke said that needed to change.

"Any system that relies on humans being perfect is not a safe system - systems are safe when there are a number of layers which can capture human error or misjudgment in order that they don't cascade into an accident," he said.

"What we're recommending is that engineering controls be introduced across the network to provide that additional layer of certainty and protection."