7.3.1 General

A good quality surface provides a safer, more pleasant experience for all road users but this is particularly relevant to motorcyclists. Factors affecting motorcyclists include skid resistance, surface contamination and debris, drainage gullies, service covers, road markings and road studs. Overbanding materials with low wet skidding resistance and poor reinstatement works are common problems for motorcyclists. Planned maintenance accounting for the needs of motorcyclists will always be more desirable than even the best reactive fault reporting system.

7.3.2 Pavement Condition Surveys and Skid Resistance

The development of the TRACS (Traffic speed Road Assessment Condition Survey) network condition monitoring equipment used on trunk roads into the Surface Condition Assessment of the National Network of Roads (SCANNER) has changed the systems and methods used to monitor local roads in England. A similar survey exists for Scotland (the Scottish Road Maintenance Condition Survey).  One of the capabilities of the system is to assess surface texture. The outputs from these systems should enable maintenance engineers to efficiently target their other tools to monitor road condition, including SCRIM (Sideways force Coefficient Routine Investigation Machine).

The current standards for monitoring the skid resistance of road surfaces using the SCRIM procedure appear to be adequate for motorcycles. One difference for motorcyclists is that the majority of SCRIM tests follow the nearside wheel track. On many bends the rider’s line is not the same, so it is important to bear in mind that the test result might not reflect the skid resistance of the surface on which the motorcyclist is riding. There are two significant areas for improvement relating to the use of SCRIM:

• Although this is standard procedure for trunk roads and motorways, it is not universally used on local roads.  It would be a major safety benefit to all road users to expand the use of the machines or to better target them using information from the new network condition monitoring systems mentioned above.
• Combining data on collisions involving skidding in wet conditions with a graphical representation of lengths of SCRIM at or below investigatory levels can form a powerful analysis tool in identifying locations where road users, particularly motorcyclists, would benefit from targeted surface maintenance.  This is a relatively simple technique using Geographical Information Systems which often form the basis of asset and pavement management software.

7.3.3 Surface Contamination and Debris

The consequences of losing grip are usually more severe for motorcyclists.  Loose grit and gravel are a major concern for riders and routine maintenance should be planned to reduce the amount of such debris left on the road. The following action points are worth adopting:

• The Code of Practice for Maintenance Management – Well Maintained Highways (DfT 2005) – last updated in 2013 – addresses safety and surface inspections. These should be carried out regularly and the opportunity should be taken to locate areas of unused carriageway where loose road material accumulates. Motorcycles can use any area of the carriageway and methods of eliminating this loose grit could be determined by realignment and priority sweeping pending other action.
• During the surface dressing season, avoid storing granular material at the roadside which could spill into the carriageway.
• Before reopening a surface-dressed site to normal traffic, road sweepers must completely remove excess material. This should be repeated to remove material dislodged by traffic. Failure to do this can lead to skidding and serious abrasive injuries to riders.
• In order to give all motorists clear warning of roadworks, use and maintain signage in accordance with Chapter 8 of the Traffic Signs Manual. Loose chipping warning signs must be prominent.
• Promptly remove mud and animal slurry. Cleansing operations need to be properly managed. Simply hosing a road with water may just compound the problem, especially in winter.
• Keep roads clear of debris which collects in areas not normally used by twin track vehicles, such as the middle of a road near traffic islands or the outside edges of roundabouts. As well as compromising surface grip, these areas can collect metal debris which can cause punctures.
• Establish dialogue with local rider user groups and adopt reporting systems to enable prompt reaction to spillages.
• The spillage of diesel, oil and other similar substances on the road surface is a great danger to the motorcyclist.  Even absorbent granules to remove these spills can be a hazard.  Consider warning signage at sites where this is known to be a regular problem.  Devon County Council’s “Spiller Killer” campaign paved the way for their wider “See it; Report it” initiative and Derbyshire County Council display ‘warning stickers’ on all its HGVs.  See Chapter 4 for more information on KillSpills campaign.

7.3.4 Visibility

‘Looked but did not see’ is a common contributory factor in accidents involving motorcycles and other motor vehicles. This puts “see and be seen” at the top of the motorcycling agenda. Unfortunately this can become a problem at sites, particularly priority junctions and small roundabouts, where planted areas and hedges can completely mask a motorcyclist. Enhancing maintenance regimes or modifying planting mitigates the risk of vegetation restricting visibility.

7.3.5 Road Markings and Road Studs

The use of road markings needs to be carefully examined from a ’motorcyclist inclusive’ viewpoint.  The position and skid resistance value of edge lining, rumble strips, large arrows and hatched centre line marking can be a significant hazard to riders, especially in the wet.  Laying new markings on top of old ones can create areas for water to collect without draining away and, in any event, where layering creates road markings over 6mm high, this would, in most cases, be unlawful.

It is a false economy to avoid relining as part of a maintenance scheme; the remaining road markings may constitute a standing water hazard. ‘Blackening out’ redundant markings rather than burning or planing them off creates a higher upstand and reduces skid resistance. The issue of road markings is discussed further in a Road Safety Audit context in Chapter 8.

Motorcycle headlamps generally give a lower level of illumination and the lean of a motorcycle into a bend deviates the headlight beam away from hazards.  Whilst many different types of road studs are now available, newer types have higher retro-reflectivity and may be more suited to well-used routes by motorcyclists.

7.3.6 Rutting

Badly rutted surfaces cause particular problems in wet conditions.  In addition to the rapid change in level and sharp ridges, they retain water and increase the risk of aquaplaning. Warning signs should be used as an interim measure but only until a planned maintenance scheme is implemented.

7.3.7 Retexturing

The various techniques of surface roughening (such as grooving) which give texture or help drain the carriageway must be carefully considered and, when used, should be accompanied by adequate signage to give the motorcyclist ample warning of what is ahead.

7.3.8 Potholes and Reporting Systems

Potholes can be one of the most dangerous hazards for motorcyclists and cyclists. Adequate inspection and repair regimes should deal with the vast majority but local authorities should encourage the public to report potholes. The British Motorcyclists’ Federation (BMF), the Motorcycle Action Group (MAG) and a number of local authorities encourage their members to report highway faults.  Many local authorities operate a single contact point to report all road-related problems.  These laudable arrangements should be widely publicised and utilise all social media channels.

The RealRider© mobile phone application (see Chapter 4) uses a phone’s integral GPS facility to pin-point a highway fault and allows a user, with the aid of the phone’s camera, to send the location and a description of the fault to the relevant highway authority.

7.3.9 Traffic Calming Schemes

Poorly maintained traffic calming measures can lead to level and wheel path changes and trap surface water. The use of block paving or stone setts as entrance features can be challenging because this is usually an area where riders need to make turns. A further problem can be carriageway breakup adjacent to new vertical features (see Chapter 3).

7.3.10 Materials

It would be worthwhile when planning maintenance schemes to consider using specialist materials on routes or locations with high numbers of rider casualties.  An example would be using accident records to select sites for high friction dressing.  Excessively wide bitumen over-banding to seal cracks and prevent water entering the road construction should be avoided as this compromises grip (especially in wet conditions) and can contribute to motorcyclists losing control. There are reported alternatives with better grip properties (FEMA 2004).

The early life skid resistance of Stone Mastic Asphalt (SMA) has caused concern due to significant amounts of surface bitumen present in the early life of the material which may result in skid resistance values in dry conditions similar to those experienced on “run in” material in wet conditions.  The use of sealing grit on SMA by some authorities has been found to provide significant improvements in early life skid resistance and its use should be actively considered.

7.3.11 Drainage

Inadequate or compromised drainage creates wet patches and water pools causing slippery surfaces and increasing the risk of aquaplaning. A particular hazard is where non-carriageway water runs across the road often in between gully positions. Gullies blocked through lack of maintenance or leaf fall are hazardous and should be inspected and cleaned regularly.  The design of traffic calming features must take account of drainage paths to ensure water does not pool in front of or behind the traffic calming feature.  It is important to remember that many people use their machines for commuting all year around.  During the winter, ice can have serious consequences for all road users, but the price paid by a dismounted motorcyclist can be fatal.

7.3.12 Lighting

The dynamics of motorcycling mean that it is critical for the rider to be able to see the detail of the road surface.  At night, consistent road lighting helps to enable any standing water, potholes or uneven service covers to be seen in time to take evasive action. Effective and well-maintained lighting at traffic calming features is important, especially at vertical features such as road humps and speed tables, because motorcycle stability is particularly sensitive to abrupt changes in vertical alignment.  Therefore, the local authority must operate a thorough and timely ‘inspection and repair’ regime for road lighting.

7.3.13 Roadside Trees

Branch lopping or enhanced carriageway maintenance should be considered where roadside trees obscure light, create a high risk of serious injury from collision or cause a continual problem of ‘leaf fall’ on the road.

7.3.14 Service Covers

One of the most regular problems raised by motorcyclists is that of service covers. Recent revisions to DMRB, TD 16/07; 54/07 and HA 104/09 highlight that designers and maintenance engineers should take every opportunity to assess the use of steel service covers in the carriageway and, where relocation is impossible, should consider replacement with high skid resistance covers.  The most challenging sites are those where the cover lies on the riding line during a change of direction, either turning a corner, rounding a bend or at roundabouts. Proposals to position new covers within the carriageway, especially at roundabouts, should be discouraged.

The British and European Standard on service covers is under review with the intention of including a requirement for enhanced skid resistance.

Consideration should be given to application of anti-skid surfaces to covers that cannot be relocated. Where utility companies intend to repair or renew apparatus in the road it should be replaced with covers conforming to BS EN124:1994 or The Design Manual for Roads and Bridges (DMRB) Volume 4, Section 2, Part 5 (HA 104/09) in high risk areas.

In new developments the local highway authority should advise on the location of covers and perhaps specify that they should be located in service strips in the verge/footway as opposed to the carriageway.  If they cannot be relocated they should be installed in accordance with DMRB HA 104/09.  In addition to location, consideration should be given to the importance of careful and skilful installation of covers to minimise the risk of avoidable rocking or sinking of the covers.

7.3.14.1 Example 1: Bristol City Council

As part of a retail centre redevelopment, Bristol City Council trialled several modified ‘surface treated’ ductile manhole covers. These covers, from the GripTop™ range by Saint Gobain, are now commercially available and won the Motorcycle Award category at the 2009 Prince Michael International Road Safety Awards.

7.3.14.2 Example 2: London Borough of Hackney

The London Borough of Hackney are trialing Structural Sciences Composites Ltd’s access covers and are testing these in a live environment on their urban roads.

7.3.14.3 Example 3: "Get a Grip"

In 2010 Motorcycle Action Group launched the “Get a Grip” campaign to raise awareness of the potential dangers posed by manhole covers and to encourage local authorities to create higher grip, cost effective road surfaces.  Further products and technological advancements can be found on the campaign website.

7.3.14.4 Example 4: Premark® Retrofit Anti-skid

Norfolk County Council has introduced a retrofit intervention at locations where motorcycles are likely to be cornering or braking and are thus less stable.  The Council’s dedicated motorcycling officer identified ‘high risk’ sites.  Over 50 covers were then treated and the study concluded that Premark® offered good value for money as part of other maintenance works.