London Dashboard

The GLA have launched a ‘dashboard‘ of data covering a range of topics, to be updated at regular and frequent intervals. It includes a number of items on transport such as journeys by public transport and by cycle hire. The cycle hire data is broken down not just by month but by day so you can observe patterns over short and long timescales. When the cycle hire scheme was launched it was expected to generate about 40,000 trips a day (see paragraph 447 in the Mayor’s Transport Strategy here) but as of the latest data (to the 8th of July) this level had only been reached five times. TfL have since said that there were record numbers of hires during the Olympics period so it will be interesting to see what the next update shows.

Filed under: Cycling, Data, GLA, Historic, London, Modal share, TfL, Traffic

Road casualties in London in 2011

In late June TfL published a factsheet on road casualties in 2011, which you can find alongside previous versions here. There were 29,257 casualties recorded by the police in 2011 (inevitably an under-estimate, since many injuries don’t get reported, particularly the less serious ones). Of these, 159 were fatalities, 2,646 were serious injuries, and 26,452 were slight injuries.

The number of people killed or seriously injured (KSI) fell 3% from 2010 to the lowest number since 1986 (the earliest year of police reporting at Greater London level). But there were huge differences in trend for different categories of road user: while the number of car occupant KSIs fell by 31% and the number of bus or coach occupants by 12%, the number of cycling KSIs increased by 22% and the number of pedestrian KSIs by 7%.

Of course, these divergent trends are partly due to different trends in traffic for each mode, with car traffic generally falling and cycling rising in recent years. But it’s very unlikely that car traffic fell by 31% or that cycling rose by 22%, so it is highly probable that the car casualty rate fell and the cycle casualty rate rose. We should get more evidence on casualty rates when DfT update this table and others in a month or so.

It is also worth noting that DfT publish very detailed data for every single recorded casualty recorded on data.gov.uk. The data is at case level so you can analyse it any way you like, but be warned that the data is quite complex (you may need to match vehicle records with casualty records, for example) so it might take some time to understand.

Filed under: 2011, Data, London, Report, Safety, TfL

Traffic speeds and congestion by region

Last month the Department for Transport published new quarterly statistics on congestion on local authority ‘A’ roads, which include most motorways and carry about 80% of all traffic in England. The chart below shows trends in average speeds (and by implication, congestion) in each region during the equivalent quarter of each year back to 2008 (click for full size).

This illustrates a few points:

• Congestion is much higher in London than in any other region, unsurprisingly.
• However, London is the only region where congestion did not worsen between 2008 and 2010 (as shown by lower speeds).
• However however, speeds increased and congestion fell in every region apart from London between 2011 and 2012.

To what extent this latter trend is due to transport policies or to factors such as different weather conditions or different economic fortunes is open to speculation.

Filed under: Data, DfT, Historic, Regions, Traffic

Bus passenger journey trends

The Department for Transport last week released new statistics covering trends in bus passenger journeys around the country. DfT’s chart sums up the trends:

Bus use in London rose increased rapidly between 2004 and 2008, levelled off during the recession and is now on the up again. In other English cities (the brown line) bus use has been more or less static since 2004 and showed more of a drop during the recession, consistent with other economic indicators.

Filed under: Bus, Data, DfT, England, Historic, London, Modal share

Car ownership in London continues to fall

We’ve posted before about falling car ownership in London, as measured by the number of cars per household. The latest figures from DfT show this figure continuing to fall in London, from 0.78 cars per household in 2008/09 to 0.76 in 2009/10. Meanwhile it’s up very slightly in the rest of Britain, to 1.21 cars per household. So there are roughly three cars for every four households in London, compared to nearly five in the rest of Britain.

Filed under: Car ownership, Data, DfT, Historic, Regions

Long-run trend in commuting into central London

The first statistics on commuting into central London were collected in the 1850s (of which more later), but the first figures comparable to the present date from around a century later. The chart below shows the trend since 1956 in the number of people (in thousands) measured as entering central during the weekday morning peak, broken down by whether they used rail (national rail, London Underground or TfL), bus or private transport (car, coach, taxi, cycle and motorcycle). NB, walking isn’t included.

The number of morning commuters peaked at about 1.25 million in 1962 and then fell through most of the next twenty years. The pattern over the last thirty years is dominated by peaks and troughs linked to London’s economic performance, with notable booms and busts in the late 1980s, early 2000s and in 2007-08.

Rail is the dominant mode throughout this period, even more so in recent years, reaching 79% of the total in 2010. In fact the more interesting changes happened on the road and only really show up when you leave rail out. Detailed data on road traffic only starts in 1969 but the chart below interpolates back to estimates from 1961 to show the broad modal split of road commuting over a nearly 50-year span. It shows buses and cars twice swapping places as the dominant mode of transport for commuters, with bus ridership sliding throughout the 60s and 70s before shooting up again in the early 2000s. Interestingly, this latter shift seems to have started before the introduction of the congestion charge: the number of car commuters into central London fell by nearly a quarter between 2000 and 2002, before the C-charge was introduced in 2003.

The most notable trends in the last decade have been the continuing fall in the car share of commuting, and the rise in cycling. The chart below shows cycling’s share of road commuting into central London since 1969. In the early 1970s cycling accounted for just 1% of road commuting (and therefore a much smaller share of total commuting), but by 2010 this had risen to 12%. Given the combined motorcycle/cycle figure in 1961 was 13%, it seems fairly plausible that cycling now accounts for a higher share of central London commuters than at any point in the past. Also, if current trends continue (a big if) it won’t be long before more people are coming into central London on two-wheelers than in cars.

I mentioned at the start that these kind of statistics were first collected in the 1850s. This refers to a survey by Charles Pearson, who hired ‘traffic-takers’ to stand ‘at all the principal entrances to the city of London, to take their station from eight o’clock in the morning till eight o’clock at night’ and count the number of persons and vehicles leaving or entering the City over the twelve-hour period. The City was a much larger part of ‘London’ in the 1850s than it is now, and Pearson measured somewhat different flows and used a different methodology, but his results, shown in the table below, are still fascinating.

Estimated number of persons and vehicles going into and out of the City daily in 1854, counting them all both ways.

Omnibus	88,000
Other vehicles	52,000
River steamers	30,000
Via Fenchurch St and London Bridge rail	54,000
Foot passengers	400,000

Railways were still in their infancy and there was no Tube yet, but the most striking result here is how many people walked into Central London. That’s not so surprising, as London was much smaller and denser than it is today so most people would have been within an hour’s walk of the City. It’s frustrating that we don’t have comparable figures on walking today (at least, not that we could easily find) but as the city is so much more spread out you would expect walking’s share to be much lower, though still significant.

Filed under: Data, Historic, London, Modal share, TfL, Traffic

Updated: trend in cycling flows on TLRN

We have posted previously about TfL’s statistics showing the trend in cycle flows measured on their network of main roads in London. Data for the second quarter of 2011/12 is now available and the charts below (and accompanying data) have been updated accordingly.

It’s important to note, though, that this is just one way of measuring trends in cycling in London, and probably not the best.

Filed under: Cycling, Data, Historic, London, TfL

Measuring trends in cycling

How do you measure cycling in London, and its growth over time? The answers to these questions aren’t just interesting in themselves – they’re also important for measuring whether cycling is getting more or less safe. Unfortunately there’s no perfect way to measure the number of people cycling or the distance they cover, but there are a few decent attempts, which this post will describe.

One measure we hear mentioned a lot is Transport for London’s count of the number of cyclists on its network of main roads, the TLRN. The chart below, from a previous post, shows the quarterly trend since 2000. On an annualised basis this shows an increase of about 150% over ten years.

The good thing about this data is that it’s available quarterly and TfL keep it pretty up to date. The drawback is that it only covers a small subset of London’s roads. The map below shows all the TLRN count sites TfL use to measure this flow.

The Department for Transport do their own counts of road traffic in London and elsewhere, in order to construct estimates of the distance travelled by each mode in each region in a given year. They survey a huge number of roads, but only once a year for main road sites (of which there are nearly two thousand in London) and less than annually for minor roads. Here’s what the trend in DfT’s count of cyclists on major roads looks like in London. According to these figures cycling on major roads in London increased by ‘only’ 78% between 2000 and 2009, much less than the TLRN count would indicate.

As mentioned above, DfT use these figures to calculate the distance travelled by each mode. The resulting trend for cycling in London is shown below. This trend is even flatter, showing an increase of only 38% between 2000 and 2010. The reason seems to be that most of the growth in cycling flows has been seen in areas where the count sites are more closely packed together so each extra cyclist counted translates into only a small increase in distance travelled (see DfT’s note on how traffic counts are turned into distance travelled).

Lastly, we go back to TfL, who in their third Travel in London report recognise the issues with the simple TLRN count and come up with a new way to estimate the number of cycling ‘journey stages’ in London on a typical day. Using data from their TLRN counts, the DfT counts and from their London Travel Demand Survey they estimate that cycling journey stages increased by 61 per cent between 2001 and 2009 (see p. 56 here).

So what you’re left with is a range of different ways of counting how much cycling there is in London, each of which produces a very different figure for the amount of growth in the last decade or so, from 38% to about 150%. Which one you use has important consequences, most notably for deciding whether the accident rate (per trip or per km) is rising or falling in London. This report from TfL says:

Comparing 2010 with 2009, total pedal cycle casualties rose by nine per cent (from 3,669 to 4,007), while the number of cycle journeys increased at a faster rate, by 15 per cent, indicating that cycling is becoming relatively safer.

But that 15% figure refers to the TLRN count, so comparing it to the London-wide casualty total is not comparing like with like. Every other measure, including TfL’s own measure of journey stages, shows slower growth. DfT calculate their own statistics on casualties per 100 million kilometres, and they show an increasing cycle casualty rate in recent years – see this recent post at Cyclists in the City for the trend, and for the raw data go here for 2010 and for previous years table 2.5a in each edition here.

In summary then, measuring how cycling has grown over time is very important, but it’s also very difficult. It’s vital to keep in mind how the different measures are constructed and what they mean if the right conclusions are to be drawn.

Filed under: Cycling, Data, DfT, Historic, London, Modal share, TfL

Change in cycle to work rates between 1971 and 2001 by London borough

For all the data showing more recent trends in levels of cycling in London (such as the main roads count we covered previously), there is very little which tells us about longer term trends. However it is possible to get an idea of long term trends from the Census, which every ten years asks every person in the country a bunch of questions, including one about how people get to work.

We’ve just had a Census in March of this year but the results won’t be out for at least another 12 months, so the latest Census data we have is from 2001. Data going back to 1971 can be downloaded from Casweb or (only back to ’81) from Nomis. In each Census everyone of working age in employment was asked how they travelled to work or if they worked at home (Note: people could only tick one box and were asked to choose the mode of transport they used for the longest part, by distance, of their journey. So this will tend to undercount the amount of walking involved in journeys to work).

The chart below shows the trend in the proportion of people who said they cycled to work in London. There’s very little change over the thirty year period, with the proportion consistently in the 2% to 2.5% range.

Things get more interesting when you go below the regional level. Data is available to borough level, and I aggregated the boroughs into Inner and Outer London (according to the ONS definition). The chart below shows the results.

This shows a fairly remarkable turnaround. In 1971 Outer London residents were twice as likely to cycle to work as Inner London residents, but by 2001 it was the other way around. Cycling to work fell every decade in Outer London (though only slightly in the 1990s) and rose every decade in Inner London.

There are some striking trends at borough level too. In 1971 1% of people in Hackney cycled to work, but by 2001 it was 6%. At the other end, 5% of Hillingdon residents cycled to work in 1971, falling to 2% in 2001.

The two scatterplot charts below illustrate the borough level trends. The first charts the cycling rate in 1971 on the X axis against the rate in 2001 on the Y axis. Boroughs above the line saw an increase in the cycling rate between 1971 and 2001, and those below the line saw a decrease. The second chart plots the rate in 1971 against the percentage point change between 1971 and 2001. In both charts Inner London boroughs are shown as blue diamonds and Outer London boroughs as red circles.


Two things really stand out. First, boroughs with relatively high cycling rates in 1971 tended to see decreases over the next 30 years. Secondly, Inner London boroughs nearly all saw an increase while Outer London boroughs nearly all saw a fall. The only Inner London borough that didn’t increase its cycling rate over this period was Newham.

It’s worth bearing in mind a few caveats about these figures. First, they describe the transport choices of residents of each borough, but not the journeys made in each borough. As many (most?) journeys to work involve crossing borough boundaries, the modal share of journeys made in each borough will be somewhat different (The City of London is an extreme case, as it has very few residents but a huge number of people commute to work there).

Second, these figures include all modes of transport, including rail, which is obviously quite important in terms of commuting in London. It’s possible to instead look at cycling as as proportion of road traffic only, but that doesn’t seem to change the conclusions very much.

Third, this data only describes journeys to work, which are certainly important but still a minority of all the trips taken in London. We’d be interested to see any similar data for non-work journeys if it’s out there somewhere.

Finally, we’ll be making the data available soon, once we work out the best way of presenting it.

Filed under: Boroughs, Census, Cycling, Data, Historic, London

Traffic casualties in London since 1901

TfL’s most recent report on traffic casualties shows that 126 people died in collisions on London’s roads in 2010. While this figure represents a terrible loss of life, one which can and should be reduced, it is also – as TfL point out – the first time the number of road fatalities has fallen below 150 since their records began in the 1970s.

It is in fact possible to go further back in history then that. Statistics for 1901 onwards were collected by the London County Council and then the Greater London Council, first covering the Metropolitan Police District and then (from the mid 1960s) the Greater London area. Fortunately these two geographies match up fairly well – the Metropolitan Police District is larger than the Greater London area, but until around the mid 60s its outer reaches were sparsely populated enough to make little difference. Using LCC and GLC statistical reports found in the libraries of the London School of Economics and the Greater London Authority, we reconstructed trends of fatalities and total casualties (i.e. including ‘serious’ and ‘slight’ injuries) in London between 1901 and 2010, shown in the two charts below.

Some clear overall patterns emerge. First, each world war resulted in a large fall below trend in both fatalities and total casualties. Taking the effect of the wars into account, the basic trend in terms of fatalities seems to be an increase to a peak of around 1,400 a year in the early 1930s, followed by a long decline that continues to this day, with the 2010 figure of 126 deaths the lowest in the entire record. Total casualties peaked much later, in the early 1960s at 70-80,000 a year, and have fallen proportionately less to around 30,000 a year.

The chart below, derived from the two above, confirms that fatalities have fallen as a share of total casualties over time, though again with notable breaks from trend at the time of the two world wars. The overall downwards trend is presumably due to improvements in emergency care and overall health over time, with the ‘blips’ during the wars probably due to a combination of factors such as blackouts and a shortage of medical care.

You can download the data for these charts in csv format here. In a future post we’ll look at the long-run trend in cyclist casualties.

Filed under: Data, Historic, London, Safety, TfL