Pedal Cyclists

Pedal Cyclists

How Effective?

Cycle helmets

 A study based on in-depth analysis of Hospital Episode Statistics and police fatal files attempted to estimate the potential effectiveness of helmet wearing in cycling collisions (Hynd et al, 2009). The study concluded if cycle helmets had been worn, a proportion of 7 per cent of head injury cases in a hospital dataset may not have required hospital treatment, and 10-16 per cent of fatalities in a police dataset may have been prevented. However, this is a conservative estimate due to the methodological limitations of the study.

  • The Hynd et al (2009) study investigated the extent and nature of the head injuries sustained by pedal cyclists, which were then correlated with accident circumstances. In conjunction with consideration of the biomechanics of head injury and the mechanics of helmeted head impacts, this information was used to predict the potential effectiveness of cycle helmets at mitigating or preventing a proportion of the more severe types of head injury, i.e. cranium fractures and/or intracranial injury.

  • The accident databases used were:

 - The hospital episode statistics (HES) database for England (1999 to 2005)

 - Police fatal file derived pedal cyclist database (2001 to 2006).

  • Ten per cent of the HES casualties sustained serious cranium fracture and/or intracranial injuries. The majority of this group (7 per cent of the total) only sustained these injuries and had no other head or other body region trauma. Therefore, if cycle helmets had been worn, a proportion of this 7 per cent may not have required hospital treatment at all.

  • The review of cyclist fatality police reports highlighted that between 10 and 16 per cent of the fatalities reviewed could have been prevented if they had worn a cycle helmet.

  • There are limitations associated with the predictive approaches undertaken by this type of study, so conservative estimates of helmet effectiveness were assumed for different accident scenarios (10-50 per cent). Further, the police fatal files reviewed were biased towards London and therefore the percentage benefit is only indicative of a national estimate.

  • No evidence was found for an increased risk of rotational head injury with a helmet compared to without a helmet

  • Cycle helmets would be expected to be effective in a range of accident conditions particularly where the collision does not involve another vehicle or where a vehicle has light impact with the cyclist causing their head to hit the ground,

 (Hynd et al, 2009)

 Cycle Helmet Testing

Cycle helmet testing sets a minimum standard for helmet effectiveness, which is specific to particular jurisdictions. Helmets are expected to be effective in a range of collision types but effectiveness depends on the particular circumstances of the collision such as the physical characteristics of the rider and nature of the object the head collides with.

A study reporting on helmet effectiveness testing found:

  • In most jurisdictions, cycle helmets are tested to ensure a minimum level of performance for a range of criteria that affect safety. Typically these include:

 - Construction requirements

 - Impact test requirements

 - Retention system (strap) strength and helmet stability

 - Definition of the minimum area of the head covered by the helmet

 - Definition of a minimum field of view (to ensure that the helmet does not impede the vision of the wearer)

  • Most cycle helmet standards are based on similar impact tests but the outcome measurements may be set at different levels. Studies into helmet effectiveness should therefore take these differing standards into account.

  • Helmets manufactured to current English standards (EN 1078 for child and adult helmets and EN 1080 for younger child helmets) have been estimated to be effective in a range of collision situations. However, effectiveness depends on the stature and injury tolerance of the rider and the shape and stiffness of the object struck by the head (e.g. a flat road surface, a kerb, or a deformable car bonnet).

 (Hynd et al, 2009)


Research on cycle lanes provide little evidence of effectiveness in the UK context. However, effectiveness seems to vary according to the level of segregation from other traffic. Cycle lanes that provide complete segregation from other traffic may provide a higher level of effectiveness than cycling lanes which do not provide segregation at all times. In these latter types of lanes, points which intersect with roads and pavements expose cyclists to risk. One study suggests that this risk may be greater than the risk cyclists are exposed to if there is no cycle lane.

A literature review on the role of infrastructure on cycling safety found:

  • There is little UK evidence that marked cycle lanes provide a safety benefit and where they cause the cyclist to come into close proximity of cars, where cycle lanes intersect with car traffic, the increased may reverse any safety benefits.

  • The nature of cycle lanes is likely to influence cyclists’ casualty risk. For example, footways that have been converted to cycleways and illegal use of footways have been identified as increasing risk.

  • Cycle paths which are segregated from motorised traffic may result in a decrease in casualty severity, however, there is no available national data to confirm this. Also, for segregated cycle paths to be effective, their surface must be maintained.

 (Reid and Adams, 2011)


Road junctions are a particular source of risk to cyclists, with a significant proportion of cycling collisions occurring at junctions (see section above on where cycling collisions happen). The literature suggests that junctions should be a focus for road safety interventions aimed at cyclists. A range of intervention types are suggested including reducing speed of motorised traffic at junctions, which seems to be the most effective. TfL (TfL 2010) carried out a trial of roadside safety mirrors in London to increase the visibility of cyclists to HGV drivers. While various road users thought it would have a positive effect on their driving behaviour in relation to cyclists, the results of the trial are not yet available.

A literature review on the role of infrastructure on cycling safety found:

  •  Junctions are a particularly common location for cyclist collisions and should therefore be a target for safety interventions.

  • Reducing the speed of traffic through junctions by introducing traffic calming interventions are an effective way of reducing cyclist casualties. Although it should be borne in mind that collisions involving HGVs are likely to be at low speed.

  • Junctions that involve traffic travelling at greater speed such as roundabouts are particularly risky for cyclists.

  • The is little evidence to support the effectiveness of cycle advanced stop lines (ASLs) although the review suggests that ASLs may be useful where there are heavy flows of right-turning cyclists.

  • Infrastructure interventions in continental Europe, which have not been implemented in UK, may be of beneficial. These include cycle lane markings that continue across junctions and cycle pre-mirrors.

 (Reid and Adams, 2011)

A study reporting on a trial of roadside safety mirrors, designed to improve the visibility of cyclists that have entered a large goods vehicle (LGV) driver’s near-side blind spot, reported that[1].

  • The roadside safety mirrors were installed at key junctions, primarily on the Barclays Cycle Superhighway routes.

  • From the perspective of LGV drivers, the mirrors were seen as a helpful intervention to improve the visibility of cyclists and reduce blind spots.·

  • The majority of LGV drivers reported that the mirrors would enable them to drive more safely but that this positive effect would not transfer to cyclist behaviour. However, those who did believe that cyclists’ behaviour would change thought this would be in terms of cyclists being more aware of their positioning in relation to LGVs.

  • A minority of LGV drivers, and some cyclists, identified a concern that knowledge of the presence of the mirrors might cause drivers and cyclists to be less careful.

 (TfL, 2010)

 Systemic Approaches

Evidence from a study on the role of infrastructure in cycling safety and An All Party Parliamentary Cycling Group report (Goodwin, 2013) suggests that systemic approaches, involving a range of interrelated interventions, are likely to be more effective than single or more piecemeal interventions. Speed reduction (in the form of speed limits and traffic calming) are an important part of systemtic approaches, alongside other interventions. Although it should be borne in mind that most cyclist collisions involving HGVs turning at junctions are at low speed, which will be of particular relevance in urban areas.

A literature review on the role of infrastructure in cycling safety found:

  • Strong evidence that reducing speed limits will result in safety benefits for cyclists as well as other road user types. Traffic calming measures and wider use of 20mph speed limits can help achieve this.

  • In other European countries, systemic interventions involving network-wide segregated cycle paths and traffic calming measures has managed to increase levels of cycling whilst ensuring safety. It is important to note that for such interventions to be successful, a piecemeal approach needs to be avoided.

  • For such a system-wide intervention to be successful in the UK, the authors argue that cycle traffic must be prioritised and invested in on a long term basis and there must be a systemic approach which balances increased cycling levels with safety.

  • The evidence on adopting legal conventions e.g. concerning priority at junctions, from other European countries in the UK is less clear and further research is needed in this area.

 (Reid and Adams, 2011)


[1] The results are based on a relatively small number of individuals and this should be kept in mind when interpreting the findings.



  • Date Added: 03 Apr 2012, 08:20 AM
  • Last Update: 12 Jan 2018, 10:46 AM