Are You Suffering from London Throat?

An article in the Daily Telegraph today (9/1/2020) suggests that if you have a constant foggy feeling with repeated coughs and colds then you are suffering from a hitherto unknown disease called “London Throat”. The suggestion is that this condition arises from breathing in polluted air and very specifically inhaling brake dust that damages the immune system, thus preventing the cells called macrophages from clearing away bacteria.

The research on which this claim was based was carried out by Dr Liza Selley and published in the journal Metallomics. Apparently the concentration of tiny metal particles in brake dust is three times higher on roads with speed humps due to the repeated braking they induce.

Comment: If there is such a cause then those who live, work and travel in London are much more likely to have suffered from exposure to particulates on the London Underground where levels of dust pollution are very high and are known to have high concentrations of metal particles.

However, the removal of speed humps which the Telegraph article suggested as a solution, and has also been recommended by NICE to cut pollution, would certainly be a good idea. We have consistently opposed speed humps on the grounds that they generate more air pollution but also for many other reasons. See this web page for a full analysis of how damaging and effective they are:

Roger Lawson


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Speed Humps to Slow Cyclists

There is a problem in Hyde Park where cyclists have been clocked travelling at more than 30 mph even though there is a posted speed limit of 10 mph. The paths in Hyde Park are shared by pedestrians and cyclists and the Royal Parks staff said they observed several near misses when they monitored the paths. Pedestrians need to walk across the cycle path at some point but cyclists do not slow down and frequently verbally harass pedestrians who get in their way.

So the Royal Parks plan to install rows of granite setts as “rumble strips” to slow cyclists at a cost of £215,000. Needless to say the always vociferous cycling lobby are objecting with the London Cycling Campaign calling the plan “outrageous”.

It is surely regrettable that this is another example of cyclists ignoring regulations and taking the attitude that everyone else should get out of their way.

Roger Lawson

Richard Branson Survives Speed Hump Collision

Well known entrepreneur Richard Branson has had a bad accident caused by a speed hump. When cycling in the British Virgin Islands he hit a speed hump and suffered a cracked cheek, torn ligaments and extensive bruising. He claims only his cycle helmet saved him from death.

He said: “I was heading down a hill towards Leverick Bay when it suddenly got really dark and I managed to hit a sleeping policeman hump in the road head on. The next thing I knew, I was being hurled over the handlebars and my life was literally flashing before my eyes. I really thought I was going to die. I went flying head-first towards the concrete road, but fortunately my shoulder and cheek took the brunt of the impact.”

This writer has of course campaigned against speed humps over many years and this is not the first example of the danger speed humps cause to cyclists. There was a very similar case in the London Borough of Bromley in 2005 which is documented here (fast cyclist on a hill in poor light conditions): (and there is lots more information on the dangers of speed humps on that web site).

With the negligible road safety benefits of speed humps, simply in the interests of improving safety for cyclists would it not be a good idea to remove them all?

Roger Lawson

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Speed Humps and Air Pollution

Air pollution from motor vehicles, particularly in major conurbations such as London, has been a hot topic of late. The impact may be exaggerated but it has certainly become a matter of public concern with the increase in diesel vehicles allegedly making it worse.

It has been known for many years that speed humps actually result in more air pollution. For example this writer published an article back in 2002 which said the following: “Pollution Caused by Traffic Calming. As a contribution to the local debate on the merits of speed bumps, it is worth covering a report produced by the  TRL (Transport Research Lab.) last year. In the past, different studies in different countries seemed to produce very diverse results, but the latest methodology seems more likely to have produced accurate figures. TRL Report No. 482 studies the effect of a number of different traffic calming measures, including road humps, cushions, pinch points and mini-roundabouts. They also studied the impact on traffic flows and delays experienced by fire engines. To quote from the report “The results of the study clearly indicate that traffic calming measures increase the emissions of some pollutants from passenger cars. For petrol non-catalyst, petrol catalyst and diesel cars, mean emissions of CO per vehicle-km increased by 34%, 59% and 39% respectively. For all three vehicle categories the increase in mean HC emissions was close to 50%. Emissions of NOX from petrol vehicles increased only slightly, but such emissions from diesel vehicles increased by around 30%. Emissions of CO2 from each of the three vehicle categories increased by between 20% and 26%. Emissions of particulate matter from the diesel vehicles increased by 30%.

The advocates of speed humps ignored this negative evidence in their commitment to road safety even though their impact on accidents is very marginal and may be a mirage.

As confirmation for the above a recent study from Imperial College, London also found high levels of pollution from road humps – indeed higher than from other forms of traffic calming (see the Daily Telegraph on the 11/6/2016 for a fuller report on this and some quotes from me).

For example they got 47% more particulates and 64% more NO2 from a petrol car when driven over humps, and even higher figures for diesel cars.

As I pointed out in my comments to the Daily Telegraph, accidents to school children are not particularly frequent outside schools so putting humps there is unnecessary. But the health impact on children of air pollution may be particularly severe. There are numerous reasons why the use of speed humps should be banned and this is yet another – see this page for lots more information written by the author on this topic some years ago (and the facts have not changed since):

Roger Lawson