Roadside advertising is a major cause of driver distraction

“Roadside objects such as billboards, flashing signs and Christmas decorations have caused a third of motorists to lose concentration while behind the wheel”

Drivers are putting themselves and other road users at risk because they struggle to keep their eyes on the road due to numerous distractions. Roadside advertisements are among the biggest distractions causing drivers to veer out of their lane as they try to view an eye-catching hoarding while travelling, according to new research.

However, there is also increasing concern over cluttered road signs causing “information overload” and putting motorists in danger of crashing as they try to decipher them at junctions. Conversely, signs that are clear, concise, relevant, reliable and timely can improve safety and reduce the number of drivers who get lost each day. In a bid to keep motorists on the “straight and narrow”, a number of vehicle manufacturers, led by Citroën and Honda, are now fitting devices to cars designed to prevent vehicles from veering out of their lane. But, there are also suggestions that new planning laws may need to be compiled governing the locations of signs and advertising.

The concern surrounding driver distraction caused by roadside advertising and signage, is in addition to long-standing concerns over in-car distractions such as mobile phone use, changing a CD or cassette and now satellite navigation. Research by Privilege Insurance has revealed that one in four drivers have become so distracted by roadside “eyecatchers” that they have veered out of lane, causing driving chaos. Overall, roadside distractions have pulled the attention of 83% of UK drivers away from the road.

Roadside objects such as billboards, flashing signs and Christmas decorations have caused a third of motorists to lose concentration while behind the wheel. A total of 41% of those drivers admit to being distracted for up to five seconds – which equates to driving 15 car lengths at 30mph – two-and-a-half-times the stopping distance required at the same speed. At 60mph, it means drivers would find themselves travelling at least the length of a football pitch without their full concentration on the road.

Dr Mark Young, an expert in transport ergonomics at Brunel University, says: “While we currently know a lot more about in-vehicle distractions, such as mobile phones, than external distractors, there is a growing body of concern about the lack of any coherent strategy for arranging roadside furniture.

“Drivers’ visual workload varies through the course of a journey and at crucial times – negotiating a difficult roundabout, for example – there is a small but significant risk of distraction from novel stimuli like advertising. In fact, this risk is probably underestimated, and we need to do more research on the possibility of excluding non-essential information when the driver is already busy dealing with the road.”

“Clutters of contradictory road signs lead to confusion that can result in collisions”

Experts suggest that planning authorities may need to draw up regulations governing the roadside location of a variety of signs in a bid to improve road safety. For example, charts 1 and 2 (below) show a “visual load map” of an urban bypass broken down into four zones – green, yellow, amber and red – based on the information demands on drivers. In the green zone, the driver experiences low mental workload from the external environment, so roadside advertising would be permissable. The yellow region signifies the driver entering an area of increased workload, so irrelevant advertising should be excluded, says Dr Young, but non-essential information such as tourist signs would be allowed.

Driving into the amber zone, motorists experience significant workload so only essential direction information and cautionary signs should be allowed, he says. Finally, the red zone marks critical workload situations. In these areas, the roadside should be reserved purely for crucial information, such as traffic lights and “Give Way” signs. However, it is not just the locations of signs that can prove distracting, but also their design, according to Dr Young. For example, chart 3 (below) highlights two examples of the same advert.

He explains: “The top image shows a number of inappropriate design aspects, the most obvious being that the colour and form of the advert resembles a temporary road sign. The driver then has to read the sign to determine whether it contains important information. From an advertising point of view, this is desirable, but it can increase search and reaction times for the driver. “Other concerns with the sign are that it is placed too close to the road, it is angled towards the driver, and it contains too much information for the driver to read in a short space of time.

“In the lower image, some of these problems have been corrected. This sign is now clearly an advertisement, it is not confusable with current road signs, and its angle and displacement from the road are such that it is better viewed by passengers rather than drivers. This version therefore satisfies the demands of the advertisers without unnecessarily distracting the driver.” But, it is not just roadside advertising that causes danger, but clutters of contradictory road signs lead to confusion that can result in collisions, according to Edmund King, executive director of the RAC Foundation.

Sometimes “information overload” means that motorists can miss the most important information. Psychological studies show that drivers can take in only around five messages at a time. Mr King says: “Driving in a rural area with traffic news on the radio, instructions from ‘sat-nav’, over-complex road signs with four different messages, means we may miss the ‘flood’ sign. We may see it but not take it in. We then end up in deep water.” Road authorities can play their part by ensuring that road signs spring no surprises and do not contribute to that confusion. Carriageway markings and road signs are a cheap and cost effective way of reducing accidents but only if they are clear, relevant and timely, says Mr King.

“Psychological studies show that drivers can take in only around five messages at a time”

The RAC Foundation says:

• Signage at locations with a history of collisions should be examined to ensure that it is legible and simple to follow. While the onus is on drivers to learn signs and re-visit the Highway Code, confusing and poorlymaintained signage can contribute to road collisions
• Signs should be erected – or road surfaces marked – much further back from all multi-lane entries to tell drivers which lane they need to get into. With better advanced signing, drivers who don’t know a road will be able to get into the correct entry lane sooner and not have to weave at the last moment
• All road signs should be regularly maintained, cleaned, kept free of foliage and be accurate

Lane departure warning systems
Citroën has equipped its C4, C5 and C6 models with lane departure warning systems designed to keep vehicles in the centre of the lane in which they are travelling. Meanwhile Honda has equipped its new Accord and Legend – both launched this year – with adaptive cruise control which regulates the speed of a car and its distance to the vehicle in front, and a lane-keeping assist system.

Citroën was also the first vehicle manufacturer to introduce audio remote controls on a car’s steering wheel – initially launched on the XM 17 years ago, they are now standard across the range, except on C1 and some light commercials. Meanwhile all C6s feature a head-up display showing the car’s speed and “Navidrive” – a voice-activated telephone, satellite navigation and in-car entertainment system – is standard on some models or available as an option across almost the entire French manufacturer’s line-up.

Citroën won the 2006 What Car? Safety Award in recognition of its “industry-leading advances in setting new standards for occupant and pedestrian safety” and a spokesman said: “Safety is an increasingly important factor of car design and Citroën is right at the forefront with safety and security playing a big part in the make-up of all our models.

“Our unique lane departure warning system is designed to help prevent accidents caused by tiredness. It uses sensors to alert the driver, via vibrating mechanisms in the driver’s seat, if the car begins to drift across lanes unintentionally. “This cutting-edge technology is another vital area in which Citroën has been able to push forward the barriers in automotive safety and in so doing will help to enhance the safety image and customer perception of the company.”