Saturday, 16 January 2021

It's 'A' Sin

I detest outdoor advertising. At best it's an ugly addition to the street scene and at worst, it makes it harder to walk along the street given that it adds zero utility.

One of the most ubiquitous pieces of outdoor advertising is the advertisement board, also known as the "A-board". In bygone days, you may have seen the odd one tucked outside a greengrocer displaying prices, but these days it seems that every shop and business operator feels the need to have one in the arms race to entice customers into their premises (Covid-19 notwithstanding).

In many circumstances, the use of A-boards significantly restrict the ability of people flow along a footway and in some cases, they can physically prevent some people from passing where the footway is narrow. For visually impaired people, A-boards create unexpected and unpredictable hazards which have the potential to cause a fall.

This A-board narrows the space between the
bench and the shop front.

To business operators and the public alike, the rules are not straight-forward, inconsistently applied and so it's no small wonder that streets get strewn with the things. I've often had it explained to me that A-boards are part of the vibrancy of places and that they show people that businesses are open. I've been told that they're needed to help direct people to tucked away businesses and criticising their use is anti-business. Well, I don't care. The ability for people to move safely and easily in an uncluttered environment trumps any of those "benefits".

From a legal point of view, A-boards are covered by provisions of the Highways Act 1980 (England & Wales). S130 is a general duty for the highway authority to protect public rights, including preventing obstruction. S137 sets a penalty for wilful obstruction of the highway - level 3 on the "standard scale", a reference to the Criminal Justice Act 1982 (£1,000) which can be imposed by a magistrate's court. S148 sets the same penalty for depositing things on a highway.

The seating space isn't taken from walking space,
but the poorly place A-board does.

S143 of the Highways Act 1980 gives powers to highway authorities to remove obstructions and S149 gives powers to remove things deposited on the highway. Scotland has its own powers under the Roads (Scotland) Act 1984, but I'm afraid I am not as conversant with these as I am the Highways Act. There are also provisions for licencing of things on the highway using S115E of the Highways Act which is a bit of a catch-all, but generally used for giving permission to miscellaneous "things" on the highway owned by third parties.

There is also planning legislation to contend with. In England, there is The Control of  Town and Country Planning (Control of Advertisements) (England) Regulations 2007 with other variations in the other administrations. The effect is, however, to generally exclude A-boards from planning law, so long as they are placed on the owner's land or with permission from the owner (including the highway authority). More guidance on this is available here. In some cases, a shop's forecourt could have accrued highway rights through public use further complicating the issue.

An A-board arms-race. Adverts jockying to grab
the attention of passers by sterilising a whole area
of footway.

In terms of managing the issue, there are a range of approached. For example, Edinburgh City Council has a complete ban on A-boards (apart from some specific situations). This isn't actually a ban per se, because placing things on the highway is already banned in law, it is just that Edinburgh has put into place a policy that it won't grant a licence for them. The London Borough of Hackney has gone even further and has a complete ban without exception. I like this approach because there are no arguments.

Other authorities have policies of tolerance so long as business owners follow general rules (positioning, carrying public liability insurance etc). I'm not entirely sure this is the right way to do it because no lawful ability for people to put A-boards out in the first place and in the absence of a licence with each owner, this is a policy of ignoring the issue. Authorities such as Hertfordshire and the London Borough of Havering operate this way, but with differing guidance. 

The footway on the left is pretty much blocked.

Many other authorities operate on a licence application whereby the owner must submit an application (with varying levels of detail) which will be assessed to reach a decision. A licence will be charged for on an annual (or longer) basis with the fee covering the administration and presumably a level of enforcement to ensure licenced A-boards accord with their licence conditions and non-licenced A-boards are removed. 

What is generally common is that where an A-board is in contravention of the local policy or a licence, it will be removed with a release fee charged. This is because having to go through the magistrates court process to have a fine issued is costly and time-consuming.

It's not just the A-boards, the streets are under pressure
for seating as well as containing "official" clutter.

So what? There's lots of clutter out there, so surely a few A-boards isn't the real problem here? That's true to some extent. There is lots of pressure on street space, whether it's "official" clutter coming from lighting columns, traffic signs and all of the other stuff; outdoor seating for pubs and cafes; and other things like telephone kiosks, telecoms cabinets and phone masts. However, other things being done badly is no excuse to make things worse.

My general approach has always been that things in the street should earn their right to be there and things which perform more than one function are even better. There are things we need to for basic utility such as providing lighting and having some traffic signs - of course these should be well designed. We might want to encourage outdoor cafe culture and that is fine if again, it is well designed and there is space which means that we should be rejected the poorly thought out. A-boards do not perform a useful function for the street or its users and so well done to the authorities which have banned the rotten things (or who won't licence them by policy if I'm being accurate!)

Saturday, 9 January 2021

Cargocycles Can Tame Suburbia

I have different ideas for blog posts listed - some I have even started. I've just done a tidy up and found a post I had started to write back in July 2017.

I had got as far as writing the following;

As I piloted our cargotrike around central London on the Ride London Freecycle a couple of weeks ago a chap drew next to be and asked about it.
It's a Christiania and it caught the chap's eye as he was Danish (Denmark being home of the Christiania trike) and he was surprised to see one in London. He asked if we had hired it for the day, but when I said it was ours, he further wondered if it was our second car which was very perceptive! He himself had recently got rid of his second car as his heavy lifting was done on his Bullitt, another Danish classic.

Cargocycles are a common sight in Copenhagen.

I don't recall why I stopped writing the post, but it's an interesting thing to come back to. My revisited fleeting chat with the Dane sparks a conversation in which both highway and spatial planning come together in shaping how people travel and the tools they have available. It also prompts thought about how policy (and therefore what gets built) shapes our environments, how we interact with them (and each other) and who we prioritise. Of course, it also has me thinking about how cargocycles can be instrumental in changing our urban fabric.

Even larger cargocycles operate at a human scale

At a basic level, the experience of using a cargocycle in a typical Outer London borough is stark in contrast with using one in Central London (or maybe Waltham Forest). Decades of spatial planning for low density housing and a stratification of employment and commercial land immediately means that people have to travel and for some things they have to travel quite a long way. 

Cargocycles can replace light vans for deliveries

Outer London (as with many urban parts of the UK) has based decisions on significant numbers of households having access to private cars and from this flows the continuance of the same type of development and highway management which maintains the status quo. What is often missed is that where a household has access to a car, it is not available to all members of that household who are left to use whatever transport options remain.

Cargocycles can fill in the transport gap between
walking and driving, especially when something or
someone needs to be transported

The thing about cargocycles is that they can fill a transport gap where a distance to be traveled is a bit far to walk (either distance or time); where something (or someone) needs to be transported; and where the distance is easily cycleabe (and that distance increases with e-assist). For example, the suburban task of doing a food shop often means having to go to a large supermarket which is a product of spatial planning policy with highway connectivity which facilitates access to such by car. 

Cargocycles are the ultimate door to door shifters
of stuff because they can go where motor vehicles cannot

The large supermarket model also favours those who are able to purchase in bulk and so in terms of time efficiency, it makes sense to visit such a supermarket infrequently, but to do a large shop. Cargocycles can disrupt this model because they can deal with both the distance and the carrying issues created/ perpetuated by the model. That's not to ignore the problem with the centralisation of all sorts of services which by accident or design favour driving, but cargocycles create competition on this uneven playing field.

Cargocycles are great for shifting small children
and they take up way less space than cars

So what? Well, my fleeting Danish acquaintance got rid of his second car in favour of his cargocycle and he assumed I had done the same. In fact we have only ever had one car, but it is true that they cargocycle has replaced many car-based trips which are too far to walk, but easy enough to cycle and transport stuff. This is important because people dropping cars in favour of cargocycles are reducing car parking demand (at home or at destinations) and freeing up highway capacity.

A shift in development density could make store
deliveries by cargocycles commonplace

Of course, most people are worried about the safety of cycling with traffic and cargocycles will seem quite alien to many, let alone being able to imagine how they would use one (secure parking and storage is a significant barrier for example). This means that we are back with the chicken and egg problem of needing to build a decent cycling networks to enable people to switch to cycles in the first place, but places serious about being progressive will be doing this anyway.

Enabling cycling makes it easy to choose a cargocycle

As time goes on, there will surely be a critical mass of cargocycle users (including commercial users) which will further erode the need to run so many private vehicles and space can be given over to cycling (and by extension walking). This has implications for spatial planning and highway policy because it nips at the heels of the model of large supermarkets, urban retail parks, drive-through restaurants and the like. 

There is always a cargocycle for the job

Developers are not fools, they look at future trends, especially those who run pension funds and other investments. Sitting on a large low density commercial/ retail site starts to look like a long term risk where the transport mix starts to shift and so thoughts will turn to higher density mixed-use sites. The challenge can be that sites such as this have been serving private cars for so long, there has never been any investment in public transport and so it is clear that cycling is going to be a vital part of many people living and working on such sites in the future. In fact, could today's retail parks be tomorrow's local or district centres.

Cargocycles: for the win

Cargocycles are the pioneer species of the humanisation of suburbia. They can help terraform low density development and provide a genuine bridge between needing a car for some tasks and a reduction in suburban car ownership. 

Saturday, 2 January 2021

The Great Stink Redux

One of my civil engineering heroes is Sir Joseph Bazalgette, probably most famous for leading the construction of major sewers in Central London as a response to a spiraling public health crisis coming from cholera.

Back in the mid-1800s, the established medical thinking was that cholera was spread by a miasma (foul smell) from polluted water. The main problem London had at the time was raw sewage was being dumped in rivers and watercourses from which drinking water was taken (there was no treatment as such). It took people like epidemiologist, John Snow, to make the link between rotten water and infection, although it wasn't until later that century that germ theory was established and overturned miasma theory.

Bazalgette was only permitted to proceed with the plan to intercept the sewers of Central London before they discharged into the Thames when the Great Stink of 1858 made conditions from the Thames so bad that it affected the sitting of Parliament. It was all lots of things happening at once, but the dealing with the sewage in the Thames had the medical theories playing catch-up to some extent.

For a civil engineer who often finds politics frustrating, the Great Stink is a great example of having to deal with professional inertia and political will in order to deal with a public health issue through developing infrastructure. It can be rightly argued that Bazalgette's work saved many lives, despite medicine not catching up for a while after and it has me thinking about parallels today.

I guess that Covid-19 springs to mind, but that is coincidental. I'm thinking of the way we have allowed our streets to be dominated by motor traffic. That we need lots of it for cities to function or be prosperous is analogous to the miasma theory - it's a long held belief within much of the transport profession as well as the wider public and therefore politicians. Like cholera, it's impacts can affect anyone, but more likely those living in poorer neighbourhoods. There is political resistance to change the infrastructure because of concerns that it won't work or that it challenges the status quo.

Of course, many have embraced the new germ theory that in fact we have to change how things operate, that it does work and that we can't afford not to do it. Are Low Traffic Neighbourhoods the modern equivalent of John Snow removing the handle from the Broad Street water pump - something we have found to be successful through experimentation (and epidemiology comes into it) before the accepted theories have changed?

Let's make no mistake. Streets are part of our living space and although Covid-19 has thrown that into stark relief, the Great Stink has been with us for well over 60 or 70 years. Rather than clean up our act, we have defecated into our drinking water and then wondered why we have road danger, sprawl and air pollution. We need to treat our streets as a public health emergency which requires both radical adjustments to how they operate along with structural change to how we design and manage them. Maybe we also need to make it personal with politicians - let them breathe the Great Stink of the 21st Century.

Sunday, 27 December 2020

The Predictable & Lazy End Of Year Roundup: 2020

Well, I said that 2019 was a tough year. I didn't reckon on 2020 did I! As the year got underway, we started to hear about a virus starting to emerge and move across the planet.

On the 16th of March, I had been been in the office for an hour or so when I got a call from my boss that we were being sent home and the office closed. This was just after couple of months in a new office (which was easier on my commute time) and so with my laptop along with the mouse and keyboard I grabbed I had to set up remotely. I remember walking to Liverpool Street Station in a bit of a daze if I was being honest.

It has been a rollercoaster of a year, but one to appreciate the small joys such as the amazing air quality we had in the Spring with the roar of the traffic gone (but which has been all but squandered). It has been nice to be in touch with the seasons and getting outside more.

Nine months later and I now have a well-established daily routine. Work has continued to flow and my firm has worked hard to look after its staff during this difficult period. Away from the laptop, I have tried to get out cycling and on the whole I have managed to get more miles under my belt than my old local commute. Mind you, the last few weeks have been tougher with some busy project work meaning some later finishes and poor weather making it less enticing to get out.

Who knows what will happen in the coming weeks and months, although I'll be carrying on with my writing with 75 posts still to go to reach the 500 I have promised myself to get to as a milestone before I decide what to do next. Here is my 2020.

The year started with a short post about wonky zebra crossings which was followed by a report on my nosing round the Eddington development in Cambridge which didn't quite meet my exacting standards.

I stayed in Cambridge for my next post looking at some awful counter-terrorism barriers which created safety problems for people cycling. I rounded off the month having a look at cycle tracks with priority over roads - a quirky historic design feature which remains fully legal to this day.

The month started with an introduction to Sweden's Vision Zero approach, a subject which has a fascinating history. Next was a look at liability and how designers could cope with rolling out continuous footways and cycle tracks despite being nervous using them.

Echelon parking was up next and then a post looking at an awkward junction in Chislehurst where the local council was putting driver convenience ahead of children's safety.

I rounded off February with a look at rural cycling networks which gave me a chance to relive the fun I had cycling in rural parts of the Netherlands.

With the help of #TheDoodle and @LDNSharkTrike I had a look at the dynamics of riding a non-standard cycle and how gradients and space affected their use. Next was a look at footway parking (again) with the news that the Government was going to consult on dealing with it in England.

Covid-19 started to hit with force and so I wrote a few words on how being sent home from work for an indefinite period had left me rather bewildered.

Taking stock of the new normal, I got out on my cycle and reflected on slowing down and seeing my world shrink, even if some people took the empty roads as being an excuse to drive like idiots.

The month started with some thinking about the concept of "flow" and how a lack of traffic during the first UK lockdown because of Covid-19 had almost had me forgetting about the act of cycling as I moved along. This was follows by a welcome return to one of my favourite subjects - kerbs - where I had a look at forgiveness.

With the impacts of the virus being felt on the public transport networks, I had a look at the legislation which could allow authorities to roll out quick changes to the street, despite a lack of interest from the government. I ended the month with a practical look at what could be rolled out quickly on the ground.

I had a closer look at the history of the local road system in and around the village of Terhole in The Netherlands and gave thoughts on what I thought it would take to deal with the right type of road in the right place.

I returned to the government's transport and highway law response to Covid in which my cynicism wasn't disappointed before following up with some more examples of cheap and cheerful ways to make changes to street space quickly.

I then got out on my cycle in the first of a series of #LDNCycleSafari posts looking at infrastructure that I could reach by leg power alone. I took a look at London's Quietway 6 in the first of two posts. I rounded off May with the suggestion that most highway infrastructure is for motor traffic.

With my tongue a little in my cheek, I asked if cycling should be allowed on motorways. A clickbait way of looking if in fact we should be bolting on cycleways to motorway bridges crossing obstacles. I then returned to London's Quietway 6 to complete my journey from Barkingside to the Olympic Park in Stratford.

Next up was a spur of the moment piece of frivolity where I jumped on my cycle once more in search of the Traffic Light Tree, I piece of art which can be found on the edge of London's Docklands. A piece of joy for the summer.

Because of the nice weather and light mornings, I headed out again at the end of June to have a look at the new layout of Waltham Forest's Whipps Cross Junction which was brilliant.

I blasted into July with my 400th blog post from Waltham Forest. This time, a trip along Lea Bridge Road which is probably the best urban main road design in the UK. It is protected junctions, continuous side streets and filtering. 

Following my post on Swedish Vision Zero earlier in the year, I had a look at the Dutch Sustainable Safety approach which is truly an integrated way at looking how roads and streets can be designed to function safely.

Next I jumped on my cycle to go and meet up with fellow blogger, Hackney Cyclist, to look around at pop-up and permanent street changes around Bethnal Green and Hackney and then a look at some new cycle tracks in the area.

My first August post saw coverage of the new English cycling infrastructure design guidance with the government's statement of intent on walking and cycling and the "Bike is Best" campaign which was a great counter to the noisy minority of people protesting against changes to our streets. 

I then asked for some honesty from people objecting to Low Traffic Neighbourhoods to be honest about their motivations and for supporters to acknowledge genuine issues. Of course, I then got lots of comments from people making my point. SomeLTN objectors have concerns about the impact on main roads and so in the absence of credible ideas from them, I took a look at the subject in a blog post which was commended at the 2020 Active Travel Academy Media Awards. This was a lovely surprise and thanks for the nomination!

I was then back on by cycle looking at a bit of East London road building history followed by a technical post looking at when we shouldn't bother using kerbs (as shocking as the idea may be).

I was back looking at traffic signals to start September and specifically why push buttons are awkward for people cycling (and how they could be improved). Next was a look at how the UK has developed a speeding culture and why design contributes to it. I then had a look at why cycling in town centres is a network issue.

The end of the month saw a look at a random Dutch junction which didn't rely on traffic signals and how we could import the idea.

As the year moved into Autumn, I was out on my cycle again looking at a couple of new Low Traffic Neighbourhoods in the London Borough of Redbridge. Sadly, the schemes didn't last long after nervous councillors succumbed to noisy protests from the usual minority of people who don;t want to change their behaviour. A huge shame as the schemes improved local walking and cycling in a very hostile high traffic area.

My next post was inspired by some Twitter idiocy by a literal Peer of The Realm and got me thinking all about pedestrian refuges. I then headed out on my cycle to the Newham - Waltham Forest border to look at an excellent joint scheme for Low Traffic Neighbourhoods.

The month ended with a look at a junction I had been regularly cycling through on my safaris and how after nearly 100 years, it remains terrible for those not driving and then my long trip over to Enfield in the first of a three part look at what is going in there.

My travels around Enfield continued with posts two and three looking at Low Traffic Neighbourhoods and cycleways.

An indulgent post next with a look at the cycles I have used in the years since taking up cycling for transport, including the day to day machine which has helped me keep active over the year. I ended the month looking at the difference and overlaps between law, standards and guidance.

A philosophical start to the winter with my thought that infrastructure drives culture and how libertarianism is street design is the opposite of the Vision Zero and Sustainable Safety movements. I then examined why 20mph speed limits are vital in making things safer on our streets.

My final regular post of 2020 was a conversation about UK roundabout design and why we need to talk about it because we are baking in subjectively unsafe layouts all the time.

So there you have it. A year which has broken superlatives. A year which has seen misery, worry and desperation, but also one which has seen people going the extra mile for others and positivity despite what is going on around us.

2021 is not going to be any easier, but I hope I can keep you a little bit distracted with this blog, so thanks for reading and try and take a little break if you can.

Saturday, 19 December 2020

We Need To Talk About Roundabouts

We have a scourge stalking the Kingdom. It creates a maelstrom of danger in the search for capacity and yet designers simply cannot see what is wrong.

I'm talking about the UK's approach to roundabouts. But before I delve in, it's worth taking a step back and ask what roundabouts are for. Whenever roads and streets meet you have a junction. A place of both interaction and conflict depending on the situation. Where things are at the interaction end, then we don't need to be too worried about interfering with how people deal with it whereas at the conflict end, we will want to manage things to keep people safe and moving.

Now maybe those comments are more around how we manage motor traffic, but we can throw walking and cycling into the mix. The difference now is we're dealing with modes moving at different speeds which will immediately pull interactions to one end of the scale. In other words, non-managed interactions are the stuff of low (motor) traffic situations.

When we are managing conflicts, as traffic speeds and volumes increase we need to increase the amount of control and this is where roundabouts come in along with traffic signals and grade separation. Roundabouts are a UK favourite method of control because they can run at very high capacities and are scalable with good space efficiency and operational safety (in terms of collisions). What's not to love?

The problem with the UK approach, however, is how roundabouts are set out to enable drivers to easily find a gap in traffic to enter them and to move round them quickly - the idea is people can see a gap in the traffic on the roundabout and simply join the flow. Of course if the person in front doesn't fancy doing the same and you aren't paying attention, then there's going to be a shunt.

The photograph above is of a large roundabout in Stevenage where you can see how the approach to the give way points puts drivers onto a trajectory where they don't have to reduce speed too much if they see a gap on the roundabout. You can also see an exit from the roundabout on the right which enables people to exit at high speed. The grade separated (different level) walking and cycling space which doesn't place people moving more slowly anywhere near the motor traffic was a conscious decision for the town's original planners. Where traffic flows are light, you'll see some drivers pass through the roundabout taking as straight a line as possible, switching between lanes as they do so. It is very easy to drive through the typical UK roundabout.

Have a look through CD116 - The Geometric Design of Roundabouts, a document from the Design Manual for Roads & Bridges (DMRB). Now the DMRB is for trunk roads and motorways which usually means a high speed situation. However, many local highway authorities will use it for road schemes which are also high speed designs and so we see the DMRB permeating both rural and urban situations (with the latter often being completely inappropriate). The drawing below is an extract from CD116 showing a "normal" roundabout which is the UK standard approach. You can see how easy it is to drive around. On the approaches, the single lane becomes two lanes as the nearside "flares" out which increases capacity. With a two lane approach, you'll often see a flare to three lanes and so on.

The actual intricacies of the design of normal roundabouts are complex and not really my area of expertise, but the high level issues of the geometry and the way that high speeds and capacity are prioritised (and enabled) are all I'm really interested in at this point. The issue I have with their use is where we then mix this type of design with people walking and cycling (and horse riding in some situations) who need to cross one or more arms of a roundabouts. CD116 has a whole section devoted to designing for pedestrians, cyclists and equestrians at roundabouts. 

The table above from CD116 gives advice on the type of crossings to be considered for situations under 40mph. Zebras should not be used where the 85th percentile speed is over 35mph which rules out many situations and is unlikely to be suitable for a rural situation. Traffic signals are for higher flows on dual carriageways. The fact that under 16,000 vehicles per day (on the busiest) arm (or up to 16,000 vehicles per day) on a dual carriageway still allows an uncontrolled crossing to be considered is pretty scary in my mind and zebra crossings on multi-lane approaches are something which makes me very nervous.

My main concern with multi-lane approaches for zebra controlled situations comes from the position that in order to cross, one must place a foot on the crossing. As one looks for approaching traffic, it's entirely possible that the viewing angle could have a vehicle in the far lane blocked from view and so the person crossing cannot see or be seen. If the driver in the second lane isn't paying enough attention, then there is a risk that the person is getting hit.

In my crude little sketch above, the lorry driver in the nearside lane is stopping to allow a person to cross and while the driver of the car in the offside lane should be reacting to the lorry driver stopping, the pedestrian crossing from the right cannot see anything in the visual shadow of the lorry. This arrangement feels unsafe. Some people would feel nervous crossing there and if they had a bad experience, they may be put off from even going there again. Signalised crossings will make people feel more confident because drivers in the visual shadow will see the signals, although being an administrative control, a red signal does not necessarily make it safe. For uncontrolled crossings with multiple lanes, you're being left to find a gap in multiple traffic streams which can be very difficult.

For uncontrolled crossings, the guidance suggests that these should be provided on kerbed islands within 20m of the give way points (otherwise people may not use them which makes sense). However, the problem here is that this places them on the "splitter" islands associated with providing the flare and high speed entry/ exit and therefore situations which are potentially very difficult to cross, especially with multi-lane situations. For speeds over 40mph, uncontrolled crossings of single carriageways of less than 8,000 vehicles per day on each approach are deemed acceptable, although we will often still have flares to two lanes at the crossing point and a wide exit lane from the roundabout. 

The image about is the Weeley Roundabout near Clacton-on-Sea in Essex. I've added the shared-use footway/ cycle tracks in the area and you can see that they cross two lanes on the approaches and wide exit lanes. To the northwest, cyclists are expected to rejoin the carriageway! The aerial view shows a newer layout on the southern arm than you can't yet see in Streetview. It used to be a single lane flaring to two at the last minute (still where people are expected to cross), but as you can see there's a long 2-lane approach. Because the roundabout is often congested (even after this "improvement", it's hard to find a gap in both lanes at once.

Give or take, this roundabout layout "complies" with the DMRB standards. Between 2005 and 2019, there were 17 collisions in the vicinity of the roundabout. 16 involved a slight injury and 1 involved a serious injury (with a motorcycle rider being hit). In the whole of this period, there was 1 slight injury collision involving a cyclist (2006) and none involving pedestrians. In the conventional wisdom we have around 0.8 injury collisions a year with people walking and cycling barely registering and therefore this must be a safe layout.

The problem is, you only have to look at the layout with the difficult crossing points and the walking/ cycling next to traffic on a narrow shared path to understand that this is subjectively unsafe and really only for the fit and the brave. I imaging walking and cycling flows are insignificant compared with motor traffic flow and therefore there simply isn't an impetus to do better. Designers will carry on delivering stuff like this because it is in a National design standard document, because obviously, it has been put together by clever people who know their stuff.

CD116 actually manages to be even scarier. Let's have a look at the segregated left turn lane (SLTL) layouts. These are arrangements where separate left turns are provided to allow that traffic movement to bypass the need to slow down for the roundabout completely - a mini-bypass. There are two main types of SLTL arrangements; where drivers move into the lane and then merge after the roundabout and where the nearside lane peels away from the approach and rejoins on the exit (lane drop/ lane gain). For people wishing to cross, these can be signalised or uncontrolled.

The image above shows an SLTL layout with a lane drop/ gain and uncontrolled crossings. Let's zoom in to the SLTL on the bottom right;

Imagine trying to cross this from bottom right to top left. Three approach lanes, a wide exit lane. Then a wait with traffic passing both sides of you before you cross the slip road. Then a similar arrangement over the next arm of the roundabout.

It took me a while to find, but there is a real live SLTL roundabout just near Crawley, West Sussex - the Cheals Roundabout and it's nuts;

OK, it could have been worse with another entry lane to cross in that southwestern arm, but look at what the designers are expecting people to use;

Imagine being in that island to the right with slip road traffic on one side and traffic entering the roundabout on the other side. This island is around 2.4m in width and so not wide enough to fit many non-standard cycles and so small, you're going to struggle to fit a family on there. As an aside and if you find yourself on the roundabout but fancy getting off it, there's a curious gap in the SLTL island (which is not in CD116);

The odd cycle gap to one side, this SLTL arrangement is a legitimate layout. Even though the Cheals Roundabout is a local authority road, the DMRB has been used to guide the design in a situation one might find on a trunk road. The designers will no doubt argue that it's a reasonable design to use and because "it's in the book" it is safe. But again, it is subjectively unsafe with a design that shouldn't have soft bodied people anywhere near.

The problem with all of this is, that if we start from a sustainable safety point of view rather than a traffic flow point of view then we would either provide fully signalised layouts for people cross (notwithstanding the safety issues which remain) or providing grade separated arrangements. Ideally, we would have a completely separate walking and cycling network. However, sometimes this does coincide with the motoring network and as Stevenage taught us many years ago, grade separation is a good solution. 

It's of course no surprise that I'm going to mention the Dutch approach and that they would not provide layouts that I have mentioned in this post. The Dutch do use high capacity roundabouts (called "turbo roundabouts") which is a whole post in it's own right, but where people are not mixed other than in certain urban situations (although these are risky and should really be avoided). If a junction is very busy, then the Dutch will grade separate it to provide a safer environment for drivers with the walking/ cycling network being kept separate.

In fact, it's not just the Dutch, there's lots of rural grade separation on Danish roads in situations where the UK would go for a roundabout. Although the Danish don't have a well developed rural walking/ cycling network to the same extent as the Dutch.

Where people are crossing Dutch roundabouts, these will be one lane in/ one lane out affairs (compact roundabouts) which are developed as a safer type of junction. Generally they are moving to walking/ cycling priority in urban areas with traffic priority retained in rural areas. I wrote a whole post about this back in 2017. 

Anyway, the UK is baking in roundabouts which are subjectively hostile to people because of a design standard which comes at the issue as a traffic capacity question, rather than a making people feel safe question. When I was looking for an SLTL example, I came across lots of design reports for locations where they are being considered, so expect to see more of these as we keep trying to add capacity.

We really do need to talk about UK roundabout design especially as the compact or continental style roundabout appears in CD116 but is often rejected by designers on capacity grounds;

This is the last general post of 2020. Next week will be my annual roundup and it certain to highlight a very strange year. It just remains for me to wish you all a Merry Christmas and thank you for reading. Stay safe and let's hope 2021 is a better one.