Self powered LED signs at the O'Riordan St, Alexandria.

Danger: Advertising signs can distract drivers. Photo: Ben Rushton

Roads and Maritime Services has been accused of increasing the risk of serious injury or death on the state's roads by failing to enforce its own rules about portable electronic advertising.

The trailers, known as variable message signs, are banned from state road shoulders, footpaths, green strips or median islands when used for commercial purposes, according to RMS guidelines, lest they ''undermine the credibility'' of those used for traffic warnings.

But the threat that the RMS will tow away advertising found on its land, as well as any on private property ''deemed to be a traffic hazard in terms of either location or messaging'' is an empty one, the Pedestrian Council says.

Its chief executive, Harold Scruby, says the RMS has not towed a trailer since introducing its guidelines in 2002, despite operators routinely flouting the rules.

The council, through a freedom of information request, sought details of all the signs that had been ''removed'' for breaching RMS guidelines in the past five years.

It was advised ''no documented records exist'' because instructions were issued over the phone.

''To be ringing them up and not putting them on notice in writing saying 'you are compromising life and limb', is utterly unacceptable,'' Mr Scruby said.

Narelle Appleby from Coates Hire, one of about a dozen companies that lease the trailers, said it immediately switched off any problem boards once notified by the RMS or a council, and arranged for them to be moved.

But she said the placement of the trailers was the responsibility of the customer, who would have been advised to make contact with the local council or the RMS.

"Now, a lot of the time they don’t do that. But that’s outside of what we can govern," Ms Appleby said.

NSW Police are also concerned about the driver distraction posed by the advertising signs, "particularly those of a multi-coloured nature".

The police said they were working with some local councils to address the problem, but officers ''have no general power to remove these signs unless causing a major safety concern''.

An RMS spokeswoman said it had an "active program of compliance" and electronic advertising trailers found on state roads or deemed to be a safety risk were removed "generally within 24 hours".

The agency last week instructed an Alexandria bedding company to remove two message boards located on private land on the corner of O’Riordan Street and Gardeners Road – a known high-risk intersection – "following community concerns" and questions by Fairfax Media.

A spokesman for Beds N Dreams, which hired the boards and arranged for them to be placed there, said he then asked Allcott Hire to switch them off immediately.

But businesses had been using the spot to advertise using electronic signs for such a long time.

"I honestly didn’t think it would be any issue," he said.

A Transport for NSW spokeswoman said RMS was developing a ''more active program'' for enforcing its guidelines.

"Transport for NSW will work with RMS in the first half of 2014 to determine if additional regulatory powers are required," she said.