PRIME site selection

Collision data analyses

As PRIMEs are an intervention intended to positively influence rider behaviour, historical data regarding locations where injury motorcycle collisions have occurred may assist in selecting sites for their use. Routine road safety reviews may lead to the identification of cluster sites involving motorcycle collisions at specific bends. It may be the case that due to the spread-out nature of such incidents and the fact that motorcycles make up a small percentage of vehicles an extended reference period may have to be used. This was the approach adopted by Project PRIME where collisions were reviewed over a 10-year period. The initial review of collision data to identify potential sites can be conducted as a desktop activity and regarded as a strategic overview.

Collisions where other contributory factors were recorded (e.g. overtaking or junction conflicts) are beyond the scope of the research conducted so far in Project PRIME. Where other contributory factors are apparent this may mean that PRIMEs are not best suited as a casualty reduction initiative.

Collision data analyses can help to identify sites where PRIMEs may be beneficial to reduce accident risk. However, accident history does not need to be the only factor to determine suitability of a bend for PRIME application. Other considerations are useful to keep in mind.

Site selection considerations

PRIMEs may be considered as a pro-active measure for bends that motorcyclists may find challenging. In such situations the positive behaviour change may serve to reduce the risk of harm to riders. Identifying such bends could involve input from riders themselves. Another approach could be to use near miss data which is an acceptable method to identify potentially problematic sites. If riders with local knowledge report problems, even if these are not generating accident data, other riders (i.e. less experienced or not familiar using a particular road) may become involved in accidents.

Throughout Project PRIME the trial sites were identified from collision data and reviews of technically demanding bends for motorcyclists. In addition to the desktop reviews, this involved experienced motorcyclists reviewing specific locations for their suitability for the research programme. Motorcyclist involvement could be more significantly increased in bend selection by approaching local motorcycle groups or police motorcycling teams as a way of finding out local bends or routes that are known to riders and may in turn benefit from the application of PRIMEs. 

PRIME trial sites had a mixture of bend radii, but actual bend radii was not a determining factor in selecting them.

During Phase 1 of the project there was no active publicity for PRIMEs. This was important in order to measure normal riding behaviour without 'priming' any riders as to how their behaviour might be changed by the PRIME road markings. Also, PRIMEs are meant to be intuitive so they should not need much publicity to educate riders about the desired behaviour change. Where there have been opportunities to engage with riders (i.e. the research interviews) a key message was that they appreciated PRIMEs are not installed using white paint on the roads which motorcyclists avoid due to expected increased loss of traction. 

Site appraisal and preparation

Once the site selection process has been undertaken there are likely to be a number of candidate bends that may be suitable for PRIME application. It is then important to assess the sites based on their readiness for installing PRIMEs either as standalone activities or as part of a road upgrade or engineering programme. It is envisaged that PRIMEs can be installed without the need for expensive road works where the road condition and environment is already suitable for their installation.

However, with sites identified, it was considered beneficial to conduct a site visit to check the location and its suitability for PRIMEs. Particular considerations at potential bend sites may include:

• condition of carriageway surface (both in terms of defects and its ability for road markings to successfully adhere to it)
• locations of any ironwork
• locations of existing road markings, particularly “SLOW” and other markings in traffic lanes that may affect rider behaviour
• locations of existing signs on approach that may distract riders from the PRIMEs or prevent installation of the PRIMEs sign at a suitable location
• vegetation that may affect visibility

Depending upon the issue identified then some action may need to be taken by the road authority prior to installation of PRIME markings and traffic signs.

The Institute of Highways Engineers (IHE) have produced an engineering guidance document to assist with reducing motorcycling collisions named “Guidelines for Motorcycling”. This guidance document provides information on key motorcycling challenges such as pot holes, road surface cracks, access chamber covers etc. which may also be relevant to the installation of PRIMEs. Where there are such features in the line of travel for motorcyclists using the PRIME road markings, these ideally need to be addressed before PRIMEs are installed.