Commercial fleets that fit an AdBlue emulator to a vehicle is equivalent to using a magnet to interrupt a tachograph, the West of England Traffic Commissioner, Kevin Rooney has warned.

He says that circumventing emission controls is a serious matter – because the emulation device defeats the vehicle’s emission control systems, approximately doubling NOx emissions.

The regulator’s comments follow a public inquiry where a haulage operator’s transport manager admitted researching the fitting of the defeat device.

Rooney told the CPC holder Patrick McNally that he had a duty to take expert legal advice or contact the Driver and Vehicle Standards Agency (DVSA) before interfering with vehicle systems.

As a result, McNally was disqualified from acting as a transport manager for 12 months. The operator, Louis McNally, will be suspended from running vehicles for 14 days from 11.59pm on February 11, 2018.

In a second case, Rooney made an order to revoke the six-vehicle licence held by Stephen Harris and Karen Phelps, after rejecting Harris’s claim that he didn’t know one of his vehicles was fitted with an emulation device.

“The operator had purchased a vehicle so that it could go in to London without attracting a penalty charge and so was Euro VI compliant,” the Traffic Commissioner said in a written decision.

“It had a tank next to the fuel tank for AdBlue. It had an AdBlue gauge on the dash that never moved. Mr Harris didn’t notice that his particular AdBlue truck never needed AdBlue. That is clear nonsense.

“I find that Mr Harris wilfully shut his eyes the absolutely blindingly obvious.”

The regulator said the fitting of the emulator device returned the vehicle’s NOx emissions to Euro III standard and would have increased the vehicle’s emissions by two and a half times at the worst.

“NOx emissions have a greater effect in densely populated environments,” he said. “That is why only vehicles of Euro IV and above are allowed in to London. Mr Harris initially denied that the vehicle had been in to London but later, when put under threat of ANPR analysis, accepted that it had been.

“With the emulator fitted and operating at Euro III levels, the operator should have paid a pollution charge of £200 per visit to the capital.”

Ordering the revocation of the partnership’s licence from 11:59pm on March 3, Rooney also criticised their “persistent use” of vehicles in an immediately dangerous condition.

A total of 12 prohibitions for defects had been issued to the operator’s vehicles in three years, while the MOT failure rate was 43% over the life of the licence, more than double the national average.

The business has indicated its intention to appeal the Traffic Commissioner’s decision to the Upper Tribunal.