Funding for highway maintenance and repair has been an issue for many years and continues to be a challenge for local authorities. The Asphalt Industry Alliance’s Annual Local Authority Road Maintenance (ALARM) report, published earlier this year, found that many local authorities are still dealing with a lack of financial resources in this area. For example, despite average highway maintenance budgets increasing by 4% in 2021/22 across England and Wales, 56% of authorities reported a cut or freeze, even before the impact of inflation is taken into account.
This means that spending has to be managed carefully to ensure the most effective allocation of resources. While repairing wear and damage to the road surface is understandably often the priority, maintenance of the roadside signage must not be neglected.
The placement of road signage is complex and must take into account a wide range of factors, often requiring a balance between different considerations. It also has an impact on the future maintenance requirements. For example, the Government issued Traffic Signs Manual recommends that warning signs should be mounted so that the lower edge is between 900 mm and 1500 mm above the height of the carriageway. The lower end of the range delivers better illumination from vehicle headlights but means that the warning signs are more susceptible to spray and dirt, which may affect their visibility.
Similarly, it recommends that all signs should be set back from the edge of the carriageway to prevent damage from passing vehicles. However, positioning signs away from the road, means it is more likely that it will be obscured by roadside vegetation.
The need for correct maintenance of all roadside signage is highlighted throughout the Traffic Signs Manual, with the document noting that this must be done ‘in order to preserve their original effectiveness and general condition.’ Periodic cleaning of the signs, in line with the manufacturer’s guidance, is important as dirt deposits on the sign will impact the likelihood that drivers will see it, especially at night. This is because the retro-reflectivity of the sign is reduced. The required frequency of cleaning will depend on the site conditions.
Furthermore, ensuring visibility is not compromised by obstructions such as roadside vegetation is also essential. The Traffic Signs Manual recommends that regular inspections are carried out to ascertain if there is any obstruction, especially during the summer months when vegetation grows quickest. While the National Highways reporting system does enable the public to report obstructions to signage, this does not provide a complete picture.
It is important to ensure that the sign is unobstructed in line with the visibility distances prescribed in the Traffic Signs Manual, which vary depending on the prevailing speed of traffic. For example, where traffic speed is between 21 and 30 mph the minimum visibility distance is 60 metres, while for speeds of 51 to 60 mph, the distance is 90 metres. Therefore, clearing vegetation close to the sign in question may not be sufficient to ensure clear visibility. This is also why the Traffic Signs Manual states that the sightline to a sign should not cross private property, such as where the sign is close to a bend in the road. As the local authority will have no control over the maintenance of vegetation and other obstructions on this land, the minimum visibility distance cannot be guaranteed.
Maintaining signs and removing obstructions such as vegetation is a relatively simple step that can significantly improve road safety by ensuring drivers are aware of speed limits and the presence of hazards. However, with budgets under pressure, it may be tempting to reduce spending in this area. It is important to remember, that maintenance is an essential part of ensuring the effectiveness of the signs and ultimately road safety.
Danny Adamson is managing director at Stocksigns
