Make the "weaker" party in traffic always automatically faultless such that the stronger and heavier participants have to anticipate more
A man after my own heart.
You asked earlier why on the continent they have less issues with cyclists - well this is one reason. Over in Europe they rule called "presumed liability" - generally speaking if there is any doubt over who was at fault, the one who introduced the most danger (ie a car) is the one found at fault from a financial perspective only (you wont get thrown in jail, but you will be responsible for any financial problems the more vulnerable party has as a result).
At 1st this seems quite bizarre to British ears, but consider it works for everyone. A cyclist would automatically be at fault in a collision with a pedestrian for example.
Its stops everyone thinking they have a god given right over others to be on the road (a very common problem in the uk, and partly illustrated by some views here

) - people give pedestrians time to move on the road, people give cyclists space, people generally become less selfish, and it works.
I think that they should be registered and have some sort of 3rd party insurance. They can be at fault for an accident causing injury to pedestrians or damage to vehicles, yet have a chance of disappearing into the sunset without a care in the world. At least with a registration, their is a chance they can be traced.
I was going to stay out of this (because life's too short) but this one does deserves a reply - Because if nothing else its half interesting.
Registration (past a very simple frame stamp) wont happen. There are a few reasons for this, but mainly its too complex (there are more bikes out their than cars believe it or not - hidden away in peoples garages etc), it would mean registering kids to cycle, it would mean registering your old granny to go down the shops, it could mean registering bikes to cycle round a park - it would essentially become an additional expense that no government will implement because it would be seen as a tax for
not driving, it would result in less cyclists, which would result in more cars on the road. Which would mean more deaths, more pollution, more congestion, more road upkeep costs....Its very counter productive ultimately.
Also...Iv yet to hear of a single motorist killed by a cyclist, and cyclists kill no more than 2 people a year (sometimes its as low as zero). When you compare that to cars, around 1800 a year die are a result of motorized traffic. Cyclists represent around 2% of traffic, but in no way represent anywhere near 2% of the danger.
As for hit and runs - The whole hit and run thing is greatly exaggerated, and misunderstood by many people. Believe it or not when someones hit by a car or bike taking registration numbers is the last thing on their mind. I believe there are 10 hit and run incidents each day in London by mortised traffic (yes...One city, has 10 a day - I have no idea what the national figure is). Most go unsolved unfortunately, in spite of the cars being registered. And when A cyclist does hit something, they are often on the ground as a result of a crash, not cycling away into the sunset.
Insurance - Im insured via 3 policies. One of which is my household cover which covers my liability away from home (I wonder how many people realise that many house hold cover policies have this?). But again, it wont happen. You can get full 3rd party insurance for you bike for about £25. If nothing else that tells you one thing, its tells you that a bike has such low potential to harm that's only £25 (and Ill bet half of that is admin fees). Cyclists are simply not dangerous enough to justify it.
Worth remembering as well, lack of insurance does not equal lack of (legal) responsibility.
To be fair I don't thinks there are any rules for speed limits on a cycle. There is no bicycle on the chart on rule 125..
https://www.gov.uk/general-rules-all-drivers-riders-103-to-158/control-of-the-vehicle-117-to-126
And even if there were there isn't a (mandatory) speedometer on a bike. Do you rely on the flow of traffic? Motorists have been using that excuse to get out of tickets for,years..
Speed limited (I believe) only apply to "motorized" traffic. Same for mobile phone use - But a cyclist can still be fined for cycling recklessly.
It purely because a bike of 1/20th of the mass of a car. And most cyclists struggle going faster than 20mph - So you might knock someone over but you wont be doing this in a hurry (or worse!)
http://www.express.co.uk/news/uk/475342/Family-of-four-escape-as-car-crashes-through-front-door