It might be hard to catch people using their phones when they're driving.

Waka Kotahi is starting a six-month trial in Auckland, with cameras set up to detect people using their mobiles.

The Agency says it wants to find out how widespread the problem is.

Crash investigator Hamish Piercy told Kate Hawkesby it could be challenging to make images from the system enforceable.

He says the cameras will use a form of AI to identify people breaking the law, but it's always possible the technology might get confused.

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