A pleasing feature of a column such as this is the debate it stimulates with readers, both in the letters column of the newspaper and in my own mailbag (what, haven't you got one?). In respect of those writing directly to me, I would be happier if more of them felt able to slough off the cloak of anonymity. This would show greater courtesy - possibly courage - and make them accountable for the views they present so forthrightly.

"Disappointed of Botley" put pen to postcard recently to complain that she/he had seen me riding my bicycle on a pavement. "Never mind that it's illegal, hazardous and inefficient what can she/he mean by that?. The problem is that your bad behaviour gives me a bad name, even when I cycle like an adult. David Cameron is not a role model."

The remark about Cameron will be understood to refer to his having been nabbed by a photographer from the Daily Mirror breaking all manner of traffic laws. These included crossing a red traffic light and going the wrong way round a "Keep left" bollard but not, I think, riding on a pavement. Almost certainly on the orders of his spin doctors, he issued a grovelling apology: "I know it is important to obey traffic laws but I have obviously made mistakes on this occasion and I am sorry."

My correspondent is perhaps hoping I might say the same thing. She/he is going to be disappointed again. What I shall say is this: I know it is important to obey traffic laws, but there are times when I choose not to, the better to preserve my own skin.

Let me explain. The road system in Oxford has been designed and installed by engineers - working on the orders of their political masters - who have some very strange notions of safety. They love bicycles and they love buses. They make a fatal mistake, though, in thinking that bicycles and buses should love each other, cosy up together. In fact, they should properly be kept as far apart as possible - the one so slight and vulnerable, the other so wide and mighty.

Park End Street, where Disappointed observed my malefaction, brings these two mismatched forms of transport into fearfully close conjunction at almost all times. The traffic engineers' insane decision to restore two-way traffic here, means there is no room for cyclists to pass the long line of buses almost always present at the lights heading west into Frideswide Square. The line would be even longer, incidentally, if the driver of every third bus did not extend the absurdly short time allowed for crossing by going through a red light. You don't believe me? Just take a look.

So, rather than sit amid a fume-belching, menacing convoy of buses, sensible cyclists are likely to make their way up the wide, empty pavement on the left. I do this often. Usually, I push my bike; sometimes I scoot; occasionally (because it seems to me no whit more dangerous) I might pedal very carefully. And it might not surprise you to learn that I am not alone in this.

Another dangerous location where Disappointed could observe me breaking the law most days of the week is at the junction of High Street and Longwall. If I am heading east, and there are no pedestrians waiting to cross in front of me, I will make for Magdalen Bridge the moment I see the lights change to green on the pedestrian crossing to my left. (This, of course, means that I am not at risk from the movement of any motor vehicles.) I do this in order to gain a head start on the queue of buses waiting to cross behind me, and so avoid having them snarling at my shoulder as I pass Magdalen College. The road, you see, is not sufficiently wide at the beginning (those traffic engineers again!) to allow buses and bicycles to proceed together. And later, when the road widens, there is the ever-present danger of a pedestrian straying into the cycle lane from the busy, narrow pavement.

It hardly needs saying that I would not cross the red light when a police officer is about. But how often is that?