Knee-jerk
Why would you tax them?

Testing and insurance, maybe. But hugely difficult to implement since kids ride bikes and expensive too since you'd have to register all bikes. The reason that you have to take a test to drive and have to insure cars is that they're dangerous and can do a lot of damage. Bikes (except in freakishly rare cases) aren't and can't.
(flimflam_machine, Fri 23 Sep 2011, 11:37, 1 reply)

A reason to tax cyclists.
To pay for the database tracking the registration number on your bike.

Which covers your license to ride.
Which can be revoked for riding illegally.
Even more fun is the possibility of bike theft becoming harder if bikes were registered to riders.

Cyclists are, in practice if not in law, immune to prosecution for causing road traffic incidents, unless actually caught and restrained at the scene they can just ride off and claim to simply not have been there.
I'm not just taking about incidents in which they are involved in a collision, but incidents in which they are the cause of a collision by means of riding badly and requiring someone else to take abrupt avoiding action.

I often ride a motorcycle* in central London, possibly my experience of cyclists is biased, but to me they are at least as much a hazard as any other road user. Often more so since they have no wing mirrors and the concept of signalling to change direction seems to have passed many of them by. We've already covered the stupidity of running red lights...

Personally I don't care if cyclists have to pay tax, I really think they should be licensed.**
Cyclists are road users, and all road users should be treated similarly.

*When it's not bent out of shape by being stolen and crashed
**Sometimes I wonder about pedestrians too
( DukeEuphoria Comes highly reccomended, Fri 23 Sep 2011, 14:42, closed)

Not so simple
Licensing is a contentious one. Superficially it seems sensible, but in practice it's unworkable and not worthwhile. This gives some good arguments:

ipayroadtax.com/licensed-to-cycle/licensed-to-cycle/

The one that I find most compelling is that minor traffic infringements are almost never dealt with anyway for cars. Your feeling that cyclists "are at least as much a hazard as any other road user" simply isn't borne out by the facts. Although bad cyclists are incredibly annoying, they are simply not that dangerous. The consequences of there actions are in almost all circumstances worse for them than for other road users, so expending a huge amount of cash to police them is a questionable investment. Better education would probably help as would simply encouraging cycling to increase the percentage of the population who regularly cycle. If cyclists didn't feel like a second-class minority it would help to build a better cycling culture.
(flimflam_machine, Tue 27 Sep 2011, 14:58, closed)