STOP PRESS [12 May 2012]: new advice from the Road Safety Council (‘Riding in Traffic‘) tells cyclists:
Be visible: When riding in [a] narrow carriageway or making turns, it is safer to position yourself in the middle of the lane.
More on this and related issues on the ‘Own the lane?‘ page.

The Transport Department’s Road Users’ Code (which is not a legal requirement) recommends that cyclists ride 50cm away from the kerb, however we believe this is dangerous for the following reasons:

• It invites drivers to pass within the lane
• It allows little room for cyclists to avoid obstacles, debris, etc
• It can put the cyclists into the ‘Door Zone’ when cycling next to parked cars

We generally suggest that cyclists should cycle at least 1m away from the kerb, or following the left tyre track of the left lane, though it may often be safer to take control of the road/lane by riding in the middle of the lane to prevent vehicles taking unnecessary risks trying to overtake you when there is not enough space to do so.

Expert advice around the world (including the 2004 cycling report by Atkins, commissioned by TD) is that it may be safest and appropriate to position yourself in the middle of a lane, to make it clear that you own it. Of course this requires a certain level of experience and confidence, but without those you certainly shouldn’t be hovering near the edge of the road inviting vehicles to squeeze past you.

Other road users do not always understand why cyclists ‘take the lane’ (otherwise known as the ‘Primary Position’), but you should never feel bad about doing so as you have the same right to be on the road as any other vehicle, and if these vehicles did not pass too close when overtaking, you would not need to do so.  If your lane isn’t wide enough for cars to pass you safely within the lane, then you should be taking the whole lane anyway.

Beginners typically “hug the kerb” and then wonder why cars pass so close.  Experienced cyclists let traffic pass when they can but they “use the full lane” when needed for safety.  If cars are passing you too close, move a bit right to show other drivers that they must use the next lane to pass you.  This way you also reserve a “safety space” to the left.  But if you collect a string of cars behind you, try to find a safe way to let them pass.  It takes practice to learn to ride effectively in traffic.

This advice in the Road Users’ Code was challenged in court by our own Martin Turner in December 2011. The charge against him was ‘Careless Cycling’ (under the Road Traffic Ordinance, Cap. 374 s46).  Faced with a robust defence, the prosecution withdrew at the last minute, assumed to be after internal review by the Department of Justice. This would appear to imply a degree of acceptance of the argument that riding away from the kerb is not careless, but this was not explicitly conceded in court, because of the collapse of the case.

The Road Users’ Code has been under review since 2010, with a revised text expected in mid-2012.

Reasons not to hug the kerb:

It invites drivers to pass within the lane

This is discussed in more detail on the overtaking page.

It allows little room for cyclists

When riding 50cm away from the kerb, there is not always enough space to avoid drains, manholes, pot holes, loose stones, glass, etc. We recommend riding at least 1m away from the kerb to make the cycling position more prominent, which also allows more room for manoeuvre when an obstacle comes along.

It can put cyclists into the ‘Door Zone’

Ride far enough to the left that you won’t run into any door that’s opened unexpectedly. You may be wary about riding so far into the lane that cars can’t pass you easily, but you’re more likely to get doored by a parked car if you ride too close to it than you are to get hit from behind by a car which can clearly see you.  A related danger in much of urban Hong Kong is buses that pull out without indicating.