LNER and Network Rail's AI deer deterrent cut expected track strikes from eight to one

Deer wandering onto railway lines are an old problem with two unsatisfying fixes: whistles mounted on trains, which are unreliable, and high fencing, which is costly. Train operator LNER and Network Rail tested a different approach on a mile of track between Peterborough and Grantham: an automated deer deterrent system, Adds, built on sensors and AI.

The system uses sound and vision sensors to identify when a deer approaches the tracks. If one is detected, a variety of audible and visual alarms start, aimed at deterring the animal away from the line; an AI camera then monitors its movement until it has been diverted to a safe distance — so every deterrence is verified, not assumed.

The numbers made the case: LNER said Adds deterred an average of 50 deer per week from the start of testing in May 2023, and while around eight incidents of deer being hit by trains would have been expected in the trial area over that period, only one was reported. The system is to be rolled out to other sections of the East Coast Main Line between London King's Cross and Edinburgh that have high rates of deer incursions.

Both legacy options fail in opposite ways — whistles do not work reliably, fencing works but costs too much to run along a long line — which left room for a sensing approach.

Varied alarms matter: a single fixed sound would be tuned out, while a mix of audible and visual cues gives the animal something to move away from.

The AI camera closes the loop: instead of assuming an alarm worked, the system watches the deer until it is actually a safe distance off.

The payoff lands on both ledgers: LNER's Danny Gonzalez said it 'can save time, stress and, most importantly, deer', and route engineer Jo Priestly tied it to fewer delays.

When a blunt fix is either unreliable or too expensive, close the loop: detect the specific animal, deter it individually, and verify the outcome with a camera instead of betting on passive hardware.

LNER called the trial a success and said the system will be rolled out to other high-incursion sections of the East Coast Main Line, which stretches between London King's Cross and Edinburgh.