Horse riders, pedestrians, cyclists and motorcyclists are categorised as vulnerable road users. In road traffic collisions, the question of who is to blame is not always obvious. Quite often, there is fault on both sides and Courts have developed methods for apportioning blame when it comes to assessing contributory negligence. In short, contributory negligence is a defence to a damages claim based on negligence. The defence can have the effect of barring any recovery by a pursuer if they contribute entirely to their own injury through their negligence.
However, when assessing blameworthiness, all is not equal for collisions between vulnerable road users and drivers of motor vehicles. The Courts recognise that individuals have the potential to bring differing levels of harm to a collision based on their mode of transport.
As interactions between different categories of road user have become common place, the law has developed to protect those most vulnerable to serious injury. In the case of Davies v Swan (1949), Davies had been standing on steps of a dust lorry that was travelling on a narrow road. When a bus tried to pass the lorry, Davies was killed. It was held that Davies was himself one-fifth responsible for the incident because of his negligence in standing where he did. Damages were accordingly reduced. However, in determining issues of contributory negligence, the reduction found by the court was determined to be "just and equitable" having regard to the claimant’s "share in the responsibility". It follows that there are two aspects of apportioning responsibility between parties in an action for negligence, namely their respective blameworthiness and the respective causative potency of what they have done. In other words, the ability to cause harm.
Of course, since 1949, the volume of vehicle traffic has increased tenfold. Reported deaths and road casualties remain disproportionately high for pedestrians, motorcyclists and pedal cyclists. In 2018, motorcyclists made up just 3% percent of traffic on our roads yet accounted for 21% of fatalities in Scotland.
As a civil litigator specialising in representing injured motorcyclists, I see first-hand the devastating injuries sustained when a motorcyclist collides with a larger vehicle. Often drivers fail to see motorcyclists, particularly pulling out of junctions onto a main road where the rider is established. However, there are other instances where speed on the part of a motorcyclist may have been a causative factor. Assessing issues of blameworthiness can be complex, as in many collisions both driver and motorcyclist have failed in their duty of care to one another. The problem the courts have to wrestle with is the concept of which party brings most harm to the event. Causative potency remains an important consideration in assessing the apportionment of blame.
There have been a number of recent decisions in the English Courts in 2019 addressing blameworthiness and causative potency. Notably, in Hernandez v Acar  EWHC 72(QB), the motorcyclist, Herdandez, was left paraplegic after a driver pulled out from a junction and into his path. Hernandez was riding at a speed of between 45 and 50 mph in a 30mph zone in Hackney, London. The case was finely balanced in regard to blame, as despite his speed, Herdandez was there to be seen. His speed was relevant when assessing blameworthiness, but the effect of causative potency tipped the balance in favour of the more vulnerable motorcyclist. The Judge apportioned blame 60 % to the driver and 40% to the motorcyclist.
There is a willingness of the Courts to look carefully at the plight of the vulnerable and the harm that is brought to them in collisions with motor vehicles. Vulnerable road users are afforded a degree of protection from the Courts by operation of ‘causative potency’ which describes the potential for road users to cause damage to each other. The greater potential for motorists to cause harm to motorcyclists is rightly taken into account by the Courts when assessing liability for road traffic collisions. Causative potency is a very relevant consideration for lawyers when acting on behalf of vulnerable road users who may have contributed to their injury through negligence as the operation of causative potency will tip the balance back in favour of the more vulnerable road user.
Thomas Mitchell - Motorcycling Solicitor