The thing about presumed/strict liability is that logically it should reduce costs for the insurers, and therefore costs for motorists.
At the minute, looking at the breakdown of insurance costs, going to court costs far, far more than it does to settle before court. Some of the examples I have seen include damages being estimated at £2000. So a pre trial settlement would costs the insurance company (and therefore the insurance pool) £2000. If they insist on going to court, and lose, this figure can spiral up to £10,000, or even £20,000, as once they lose, they will have to pay court costs, their own costs, and the costs of the injured party, on top of damages.
But our current system encourages motorists to avoid an early settlement, as the onus of proof is on the injured and vulnerable party. As such, insurers can sit back and stick to their guns, continuing to deny liability.
Presumed liability switches this around, and puts the onus on to the more powerful road user. If a motorist has acted negligently, and is faced with having to demonstrate fault on the behalf of the vulnerable road user in order to escape liability, it is far, far less likely that they will get anywhere close to court scenario. Thus costs are reduced for everyone, insurance premiums will fall, and there will be a reduced burden on the already strained court system.