At the bottom of my road, where it meets Royal Hill, there is every few seconds a sad little tableau. An impatient car (how can a car look impatient, you ask? But it does) drives up to the junction from the London direction. The driver slows to turn into my street, then notices the big notice saying "Road closed - No access to Shooters Hill," whereupon he speeds up again and heads for the permanant traffic jam that is now central Greenwich.

At the top of my road, where it meets the A2, there is an even more poignant sight: a constant parade of U-turning drivers who have ignored the sign at the bottom of the road (there's so little trust in government these days, isn't there?) and driven all the way up, bashing the road humps in their haste, only to find that the warning is in fact correct, and their path is blocked by a high fence and an orange wall of traffic cones. Like that BBC reporter in the Falklands, I sit in my study window, counting them all out, then counting them all back.

For forty-eight hours now, pretty much every side street in West Greenwich has been filled with probing, questing motor vehicles, desperately trying to find an eastbound route without a 45-minute queue - and failing every time. The main roads are just filled. During this evening's rush-hour, traffic was completely solid on Greenwich High Road, with something like 250 crawling cars between the Deptford Broadway lights and St Alfege's church. Much of Blackheath village, too, is at a standstill. The old buildings of both places shudder beneath a constant parade of heavy lorries. Horns and emergency service sirens wail into the night.

The cause, as we probably all know by now, is that TfL have closed the eastbound A2 between the bottom of Blackheath Hill (at the junction with Greenwich South Street) and Charlton Way/ Shooters Hill Road. For the next two months. To install a cycle lane.

I happened to be up very early on Sunday morning, when the closure first went into effect. From 5.30am on the quietest day of the week, there was a procession of dozens of cars down my street as the first stage of the diversions kicked in. That was when I knew that this was going to be bad.

Even most foot access has been blocked by the fence - there's only one pedestrian gap in it between the tea hut and Dartmouth Hill. West Greenwich has been cut off from Blackheath by land, air and sea.

Now, I'm a cyclist - I've never driven or owned a car in my life - and I've spent years asking for more cycle lanes. But I really don't think that essentially pouring a giant vat of glue over the whole of Greenwich and Blackheath for the next eight weeks is a price worth paying for this one.

For one thing, there are already three parallel, and far nicer, cycle routes to the A2 - along Dartmouth Hill, Hare and Billet Road, Mounts Pond Road and Long Pond Road; up through the park to Vanbrugh Park; and along the river and through the grounds of the naval college. That last one doesn't even involve a hill.

Even the justification in TfL's own press release is rather carefully worded: "This stretch of the A2 runs through Blackheath, an area that attracts many cyclists and pedestrians," they say. The "area," yes. The A2, not so much.

The other reason for the closure is so that TfL can "reconstruct the carriageway" and install new streetlights. But what exactly is wrong with the current streetlights? What does reconstruction mean - does it mean resurfacing? What was wrong with the previous surface? Why does it all have to take two months? (Why, for instance, aren't they working at night on the stretch across the heath, since there are no residents to disturb?) And let us not forget that the Blackheath Hill stretch of the road was subject to "reconstruction" only five years ago following the Blackheath Hole collapse.

The cynic in me does wonder whether this is another part of "Transport for Livingstone's" historic jihad against motorists. Perhaps closing down this main arterial route is another way of showing those despised creatures (many of whom, to compound their offence, are white, heterosexual men from the suburbs) the error of their ways.

The other historic Transport for Livingstone impulse that this closure clearly satisfies is the need to spend large amounts of money on projects which don't seem of obvious or front-rank importance.

You may, of course, object that Ken is no longer in charge. But this was presumably planned when he still was; and in any case, for the most part, under the new regime, TfL has gone on pretty much as before. Recently, I described to an appreciative senior City Hall figure some of the more bonkers ways in which TfL has been wasting money, ways that need to be mended rather more urgently than the A2 if the organisation is to survive the downturn with its services intact.

For the next eight weeks, though, we appear to be stuck with this. Let's hope it is just eight weeks, shall we? Let's hope the works don't overrun; let's hope, above all, that they don't open up the Blackheath Hill hole again and let us in for another two years of local traffic hell. They're bound to have thought of that, aren't they? Aren't they?