If you go back to the woods today (again!)

Those of you who have been following this blog a while will remember that I took part in two of the Transport for London (tfl) Safer Cycling Innovations trials earlier in the year at the Transport research laboratory (TRL). I went back again last week and this time, I have some of my own photos!

This time, it was a day hosted by the Chartered Institute of Logistics & Transport (CILT), but delegates included a wide range of people from many organisations. Incidentally, CILT has created The Hub, a cycling resource which has a fair bit of information from the former Cycling England which was shoved on the bonfire of the quangos by the greenest government ever.

The day was split into two parts. First, there was a tour around some of trial sites within TRL with a chance to ask the project staff questions about the trials themselves. The second part of the day saw a various presentations about cycling schemes around the UK and indeed the world.

On the trials, the first thing I saw was the TRL car simulator. Essentially a car in a room, surrounded by projectors, but Grand Theft Auto it was not. The car sat on little jacks which could give a feeling of acceleration and movement and even after a few minutes, the oncoming vehicles were uncanny.

The trial allowed different road layouts to be tested in a perfectly safe environment and included ideas for continuing cycle lanes across side road to reduce the risk of left hook. An interesting fact was that TFL calibrates the set up from time to time by taking a car out on the track to compare the handling and so keeping the model accurate. The car had cameras watching the driver and so could track eye movements and so interesting data could be had.

Then, we moved onto the cycle simulator which was on a series of 5 large TV screens. The main three gave a wide field of view. One on its side gave the view down onto the road and one was set out to allow the tester to see what was happening over their right shoulder. The bike was a London Cycle Hire model, but the simulator could be set up with different machines. Indeed, the set up was luggable with a van and so could be set up anywhere.

The view was uncanny again, but the set up couldn't really create the feedback to the cyclists in terms of uneven roads, leaning and so on. The virtual drivers were gifted with advanced artificial intelligence and "knew" the bike was there, even to the extend bad driving could be thrown in. One thing TRL are looking at is whether cyclists can signal and so change the behaviour of the AI.

Sort of Dutchish. Image from Google Maps.

Outside, we were led to the now quite famous Dutch Roundabout. Essentially, it is based on a "continental" or "compact" roundabout which is arranged with tight turns for traffic, a one lane in/ one lane out set up, a single lane width circulatory area and an overrun for larger vehicles. The idea is to keep traffic speeds down so people move through the roundabout smoothly and safely.

The "Dutch" element was to put a cycle track all the way round the edge of the roundabout, set back around 5 metres from the edge of the traffic circulatory area. Various entry and exit arrangement were provided with a varying type of protection from traffic and the track is set up so right turning cyclists go three-quarters of the way round the roundabout. For pedestrians, crossing points are provide outside the cycle track circle. Various road markings and zebra crossing arrangements were in place (and some uncontrolled crossings for pedestrians). 

This arm has dragon's teeth which are little triangles indicating that
drivers much give way to cycles as well as the usual zebra stripes.
Leaving the roundabout, the same markings are present and mean
give way as well. The neatest arrangement, but not UK legal.

Some of the layouts were (in my view) almost UK legal and some were a little more "non-standard", including "dragon's teeth" give way markings and "elephant's feet" marking the cycle track where crossing the carriageway. Things were set up to give cyclists priority over traffic.

The one thing which does stick out (of the ground!) is the absolute forest of Belisha beacons at the zebra crossing points. In the UK, zebra crossings have to have zig-zags, stripes and Belisha beacons, whereas in other countries, the stripes alone are enough. In my view, I cannot see a major need for Belisha beacons where stripes are used over a cycle track to give pedestrian priority, although I would be interested to know the views of visual impairment representatives. Perhaps a black and white zebra bollard is the answer, perhaps with a tactile symbol on top to help those with reduced vision?

Leaving the circulatory area, drivers need to give way to cycles at the
dragon's teeth.

There was a debate on the relatively short distance between the cycle track and the traffic give way point at the roundabout. One thought was that drivers are larger cars and vans would end up stopping at the roundabout with their back end blocking the track. Conversely, the other thought was that in seeing what was going on, drivers of larger vehicles might stop at the zebra to allow cyclists or pedestrians to pass before moving the the roundabout give way. I guess that is what the trial will be showing us! As for when such a layout will be tried "live" on the streets of London, well my money is on the Lambeth Bridge northern roundabout.

I think this arm is almost UK legal. Drivers leaving the roundabout
have to give way to cyclists and then the zebra crossing as normal
beyond. The one thing not right for the UK is that the cycle track is
meant to be on a speed hump which is daft. Of course, the profusion
of road markings is very messy and needs to be tidied up.

Next up, the protected cycle track trial. TRL had set up various 100 metre sections of cycle track using different forms of protection to gauge the views of people cycling, driving and riding motorbikes. They tested a kerb, a line of traffic cylinders (which you can just see in the photo, thy are just bolted in and are flexible if hit) and a line of Zicla Zebras (which people are calling Armadillos in the UK - I guess to stop confusion with zebra crossings!). TRL used detectors in the track surface to gauge speed and riding position which will give some interesting data.

The Ziclas have already been deployed in Royal College Street in what is now known as a "light segregation" scheme, that is, people riding bikes can go in and out of the cycle lane, but are protected from traffic.

Not surprisingly, people cycling felt safer with the kerb, but the other two methods also made people feel safer. Drivers, apparently, were quite happy with the separation, but motorbike riders were unhappy at having lost the "escape lane" created by a paint only cycle lane.

Gentle entry angle into bypass.

I am a fan of the Ziclas (subject to pedestrians not tripping over them) and how they have been used in Royal College Street, but only time will tell if the idea is rolled out more widely, although layouts using them are likely to by in the forthcoming and reworked TfL London Cycling Design Standards. What we can be doing now is using the cylinders to create almost instant protection for people on bikes which would allow a rapid roll out of facilities rather than waiting to spend a fortune on kerbing as layouts might need tweaking. Money could then be spent getting junctions sorted out.

The passenger islands was a bit narrow for my liking, but it does
allow to test for crowding and he impact on cycling past.

We then went for a look at the "floating" bus stop/ bus stop bypass/ bus stop island arrangement which was one the trials I took part in earlier in the year. Essentially, the layout provides a cycle track behind the passenger waiting area (which is on an "island") so that people on bikes don't need to overtake buses. Passengers need to cross the cycle track and TRL trialled uncontrolled crossings, a zebra crossing (more Belisha beacons!) and a humped zebra crossing. Speaking to others, it is seems that the trial layout is better than the one recently installed on the London Cycle Superhighway 2 extension at Stratford. Oh dear!

A small hump at the zebra crossing to encourage those on bikes to
slow down and let people cross.

The zebra crossing. I am pedantic, but the Belisha beacon post
and tactile paving on the far side should mirror the layout on the
near side as the track is one-way. I am so sad!

At the end of the bypass, the bus stop island gives protection from
following traffic and has a gentle taper again.

The final trial of the day was a look at cycle signals, which was the other trial I took part in. The first layout was a puffin crossing which had the usual traffic signals for drivers, but these were replicated by little signals with cycle logos and showed at the same time as the main traffic signals. At the moment, full-sized signals are the only permitted type for cycles and the red cycle stop is not allowed. 

To do anything remotely useful at the moment, we end up with lots of poles and signals and potential for confusion where drivers and bike riders look at each other's signals by mistake. The little signals placed at a low level cannot be mistaken. TRL have had to test the red cycle stop on full size signals before then trying the cycle signals. All part of the "fun" needed to get Department for Transport Approval which may well be next year according to those with ears to the ground! 

We then wandered up to a four arm signalised junction with one arm being a one-way street. As with the roundabout, each arm was a little different and TRL had been testing various sub-arrangements. We got to see an example of "early start" which has usual traffic signals at the vehicle stop line and a little cycle signal at the cycle stop line of an advanced stop line (ASL).

The idea is to give bike riders a green cycle signal a few seconds before traffic. This will allow cycles to pretty much clear the junction before traffic is released and would stop the left hook problem at traffic signals. The problem with early start, though, is that it offers no protection to bike riders when the main signals are green. That issue aside, getting the little cycle signals approved by DfT will open a huge range of possibilities - that is for another post perhaps!

The afternoon was in the warm lecture room and I won't go into detail here, but I would say that TfL's Brian Deegan gave an interesting insight into the Royal College Street scheme and Phil Jones (of Phil Jones Associates) gave a galloping piece on a world-wide study tour of cycling infrastructure (a report coming out soon hopefully). 

What I found especially interesting, though, was the presentation given by Brighton & Hove Council on the Lewes Road Transport Improvements which has taken a dual carriageway and remodelled to give a 2 metre cycle lane, 3 metre bus lane and a 3 metre traffic lane. The bus stops are floating and since opening, there has been a significant shift from private car to bike. I am looking forward to the report planned for the scheme. There was also the Old Shoreham Road scheme which essentially stuck a Copenhagen style cycle track on each side of an old main road.

I do get to have some interesting days out of the office and this one has left all sorts of ideas rolling around in my head!

King Duncan's Road: A Slippery Slope Or A Bridge Too Far?

Zenbike has been looking at how to connect the Raigmore Estate in Inverness with the rest of the world for walking and cycling and has asked twitter for help. here are are a couple of ideas at each end of the scale.

The Raigmore Estate. The yellow line is the Golden Bridge which
crosses the A9 to connect to The Inverness Campus. The blue line
is a potential cycle route through the estate which then heads west
towards Inverness City Centre.
Image adapted from Google Maps.

The Raigmore estate on the eastern edge of Inverness is surrounded by large roads and sits on a bit of a hill. It has recently been connected to The Inverness Campus by the Golden Bridge to the east which is a 290 tonne walking and cycling bridge. The problem is how this new pedestrian and cycle route can be connected up to the west of the estate towards the city.

King Duncan's Road is the only road access to the estate and as it heads north-west to the A865 Milburn Road, the road becomes narrow and goes downhill steeply.

King Duncan's Road as it approaches Milburn Road. You can just
see a roundabout in the distance, but the road bends right and joins
the main road to the east of the roundabout. No space for cycling
here!
Image from Google Streetview.

Looking north-west, the right hand side of the road has a retaining wall holding back a steep bank and on the left hand side, there is a footway with a steep bank behind. This may all be fun for goats, but for people trying to cycle on the road here it must feel unsafe and heading south-east, it is literally an uphill struggle!

View looking back up the hill towards King Duncan's Road from the
roundabout on Milburn Road. The arrow points at the retaining wall
in the previous image. here is a path (with steps) down the bank
which gives a more direct route than follow King Duncan's Road all of
the way to the bottom.
Image adapted from Google Streetview.

So, the problem is how we create a safe cycling route between the estate and Milburn Road. I haven't especially looked at the estate itself, but the estate roads are wider (beyond the hill). A safe cycling route might include the road itself if vehicle flows and speeds are low, or there may need to be some redesigns and possibly use of some of the green space through the estate. The traffic data isn't available, but I would suggest that it is needed to be able to make a proper informed feasibility.

Not sure I like this layout with the bend and the hill. The idea is
vehicles only go into the cycle lanes when they have to, but it might
work. Needs more traffic flow data.

If the speeds and traffic flow are low on King Duncan's Road, the stock answer may have been putting in some advisory cycle lanes with coloured surfacing and the centre line removed. This has been used elsewhere in Europe (link to As Easy as Riding a Bike), but relies on very low traffic flows. I think that here, the traffic flows might be a little high and certainly it won't feel like there is much protection.

The Golden Bridge - heavy engineering and big boy's* toys.
Image from urbanrealm.com
*yes, I know, don't write in!

Next up the "traditional" UK food chain would be a shared-use cycle track as in widen the footway a bit and put up some signs. Again, it might be OK if there are not a lot of pedestrians, but the current footway is narrow and not really up to a proper job. I think I am leaning towards something a bit better as after all, we have a new bridge over the A9! The big problem with King Duncan's Road is that it sits on the side of a hill and any widening needs some engineering. But frankly, if that is the right answer, then that is what needs to be worked up and promoted as the solution.

OK, to widen, it would be easier on the left hand side as building a structure to retain the widening would be easier than building a higher wall into the existing embankment on the right hand side. We could have a separate cycle track with a kerb upstand between the carriageway and the track and in turn, the track and the footway. Width would need to be about 2 metres for the footway and 3 metres for a two-way track.

From the other direction.
Image adapted from Google Streetview.

A proper job would have a decent survey and I am sure levels would need to be played with to get reasonable gradients in terms of pedestrian comfort and cyclist safety (i.e. going downhill quickly!). Given the huge bridge and also the fact that a retaining structure has been built on the right side of the road, why shouldn't some proper funding be invested in a decent layout for walking and cycling?

I think what I am trying to get at is that there is always more than one way to skin the proverbial cat. If we want to try and make people feel safe, then we might have to spend some money. In the cycle lane example, the traffic flows might be so low that actually it works. After all, the estate goes nowhere for vehicles. But, I suspect that it might be get busy enough to put people off and that means getting the civil engineering tools out.

There might be some middle ground in slight footway widening to make it just enough for a shared-use track and that might be enough for the estate's community, but with the bridge over the A9, then surely something a bit more substantial will be needed to get cycling numbers up without affecting pedestrians?

Of course, the idea which is beyond my "Option 2" may well be to connect the estate directly to Milburn Road with a long bridge which bypasses the roundabout altogether for a direct route towards Inverness. But that would be a whole other bit "armchair design". If you have any suggestions then please do comment or tweet!

Cycling In London: What Could Be Done Now

after the 5th cycling death on London's streets in 9 days, people who use bikes are understandably more angry and frustrated than ever and they are demanding immediate action. What could be done quickly to change our streets?

Cast your mind back to this time last year. The Great & The Good were patting each other on the backs about a huge sports day going wonderfully well (OK, I did get into the Olympics a tiny bit - mainly the road cycling!). What made the Games run so well was in part due a tonne of organisation in the run up to make sure the transport worked and that included the road.

A bit hard to read, but here is a map of the ORN.
Image from TfL.

Casting my own mind back even further, a year in advance, my monthly traffic liaison group meetings (where people like the emergency services, London Buses, highways bods and so on meet to discuss operational issues) had a standing agenda item for the Games with a fair amount of time devoted to the Olympic Route Network (ORN) which was arranged to help speed the "Games Family" around London by road, including "Games Lanes" - like bus lanes, but for Games people only, even cyclists were banned.

The ORN was under the management of Transport for London, but was implemented by powers given to the Olympic Delivery Authority (ODA) by the London Olympic Games & Paralympic Games Act 2006. S10 of the Act gave the ODA powers and responsibility for drawing up an Olympic Transport Plan. S11 gave the ODA the ORN powers where designated by the Secretary of State. Finally, S12 required any authority which normally looked after a road designated as ORN to cooperate with the ODA. There were other sections to deal with Traffic Regulation Orders, enforcement and road closures.

A sign used on the ORN to show a Games Lane.
Image from BBC News.

In other words, here was something definitely of London-wide importance and of course significant for the UK, which needed all London traffic authorities to cooperate with by law. In other words, we are able to debate and negotiate, but the ORN is coming, best get used to it. 

There were complaints and objections that this was being done to keep the International Olympic Committee happy (well it was) and that the draconian powers would ride roughshod over the ordinary punter (it did a bit). But, the whole think went of pretty much perfectly in terms of a transport plan.

So, back to my monthly meetings. I remember a traffic copper moaning that there were Games Lanes on some pretty major routes and emergency vehicles were not allowed to use them. I cannot remember if they were allowed or not in the end and certainly the ORN was not used as much as the original proposals suggested; but the huge transport PR build up and planning paid off. Even in Outer-London where there was mainly little Games-related stuff, risks were planned to make sure there were no hitches. The detail was actually all put in place within a year of the games starting, despite having the Act in place long in advance.

OK, on a different tack. What happens when a water main bursts in Central London? (and they do quite a bit). Do people sit in stuffy rooms discussing how best to repair the main? Do they come up with an action plan? Do they suggest producing design guidance? Do they hold a Parliamentary Inquiry? Of course not. Out come the cones, roads are closed and an army of people in yellow vests get on and repair the main.

Look, planned roadworks. We can cone stuff off to keep the workers
safe from traffic!

Where there is a utility burst or failure, where a bridge develops cracks or where there is a building fire, roads are just closed. Believe me, I have "just" closed roads many times over the years because of immediate danger to the public. The traffic is managed around the scene and it might cause congestion. If the incident goes on a long time such as what happened with the Hammersmith Flyover, drivers adapt and things reach a normality relatively quickly (and huge lumps of cash can be found if a big traffic bridge needs mending!). If things are closed or restricted for any length of time, the local highway authority will follow up and put a temporary Traffic Regulation Order in place (or the quicker "notice" version which can be used in an emergency).

The other thing to note is that if a utility, a highway authority or even a developer are planning a scheme which needs road space on a temporary basis, all sorts of temporary arrangements are possible such as barriers and cones, traffic diversions, temporary traffic signals (including push-buttons), steel and concrete barriers, lighting and so on. The basics are covered in "Safety at Street and Road Works", but more complex layouts are possible.

The main legal powers for highway authorities wishing to exercise temporary arrangements is contained within S14 of the Road Traffic Regulation Act 1984. Paragraph 1 states;

If the traffic authority for a road are satisfied that traffic on the road should be restricted or prohibited

(a) because works are being or are proposed to be executed on or near the road; or

(b) because of the likelihood of danger to the public, or of serious damage to the road, which is not attributable to such works; or


(c) for the purpose of enabling the duty imposed by section 89(1)(a) or (2) of the Environmental Protection Act 1990 (litter clearing and cleaning) to be discharged,

the authority may by order restrict or prohibit temporarily the use of that road, or of any part of it, by vehicles, or vehicles of any class, or by pedestrians, to such extent and subject to such conditions or exceptions as they may consider necessary.

Paragraph 2 states;

The traffic authority for a road may at any time by notice restrict or prohibit temporarily the use of the road, or of any part of it, by vehicles, or vehicles of any class, or by pedestrians, where it appears to them that it is

(a) necessary or expedient for the reason mentioned in paragraph (a) or the purpose mentioned in paragraph (c) of subsection (1) above; or


(b) necessary for the reason mentioned in paragraph (b) of that subsection,

that the restriction or prohibition should come into force without delay.


The important ones are 1(b) and 2(b). Essentially, something is needed because of danger to the public (which has nothing to do with road works) and the use of the road or parts of the road can be restricted - hold all of this in mind.

In terms of numbers of trips made, or distance travelled, cycling remains numerically safe, but this is not the whole picture as people don't feel safe - this is subjective safety and it is a huge barrier to overcome. The media reporting is interesting, as for the first time it seems cycling deaths are getting the kind of coverage that one would get for a rail crash. The difference is that with a rail crash, speed limits and temporary measures come in immediately until more is known about the causes. 

Rail systems and procedures are refined over years  and this mean that a rail death is rare. With roads, the police are put under immense pressure to get things reopened and "back to normal" as soon as possible. Certainly, crashes on motorways are heavily politicised because of "economic impacts". Highway authorities often (but not always) act in response to a crash where a police incident investigator raises an urgent issue such as worn road markings, surface defects, blocked visibility and the like. With a death, a Coroner will sometimes comment or report that things need to be done. Clearly an inquest is an ordeal for those left behind, but as a professional I can tell you that giving evidence at one was the worst day of my career and I don't care to repeat the experience.

So, where do my ramblings get us and what do they have to do with people getting killed when they are just trying to get around on their bikes? Well, my point is that despite the technical reports, the safety audits, the press coverage, the outrage, the Coroner's view and all of the opinions given about cycle safety, people are getting killed, people are angry and people are demanding change. 

Those who have followed my posts will know that I think we should be planning things properly and dealing with the difficult issue firsts, but even I will admit that as far as places like the Bow Roundabout and the A11 go (Cycle Superhighway 2), there is an immediate danger to the public and we have an armoury of legal processes which we can put into action within a few weeks (with proper care). We can ban some of the left turns, we can cone or barrier protected cycle lanes, we could rearrange the traffic signals at Bow to give push-button or fixed time to cycle (and pedestrian) only phases, we can introduce 20mph speed limits. If some layouts don't work, we can tweak them. We have experimental traffic orders to play with and in fact, we might learn something as we go. This could start to address some of the serious actual and subjective safety issues and perhaps even show what latent demand there is for safe and protected infrastructure.

Longer term, the Government, like it did with the Olympics, could compel the London boroughs to cooperate with Transport for London on pan-London issues for cycling safety and allow TfL to properly designate key cycling routes or areas which boroughs would need to accept or challenge through a proper and transparent process. The Government could push legislation to exempt pedal cycles from many aspects of traffic regulation (in the way they did to make no entries and contraflow cycling easier in terms of traffic signs). They could resurrect Cycling England to promote and coordinate best practice. They could even go the whole hog and create an active travel act in England!

Over the coming weeks and months, there will be more protests. There will be debate between those who want unrestricted motoring to remain and those who want active travel, but above all, nothing will happen unless and until there are politicians ready to stick their necks out to make things happen.

What A Load Of Bollards!

bollards! they are everywhere on our streets, but do we really need so many of them? What are they for? who do they help? who do they hinder?

So, what are we talking about? "Bollard" is a catch-all term to describe short posts stuck into the highway. They are made from steel, cast iron, timber, plastic - in fact any half-robust material will do the job. They come in a range of colours and shapes and are ubiquitous on our streets.

The idea for this post came a while back when I got an email about a new Traffic Advisory Leaflet; TAL2/13 - Bollards and Pedestrian Movement. TALs are a series of government advice guides covering all sorts of highways and traffic stuff. Some are good, some are bad and this one is particularly ugly. Coming hot on the heels of TAL1/13 - Reducing Sign Clutter, I thought that at last, something to help argue for a reduction in bollards which clutter the place up for pedestrians (and cyclists!). Oh dear. I was wrong.

Great George Street, Westminster. On the left, the Institution of
Civil Engineers. On the right, part of the HMRC complex.

TAL2/13 is issued by the DfT and the Centre for the Protection of National Infrastructure. In essence, rather than being a helpful document on the impacts of bollards on pedestrian movement, the document is a narrow study into justifying the use of bollards to prevent vehicle-carried bombs getting close to important buildings and facilities and the earth-shattering conclusion that bollards used for security protection don't impede pedestrians. What a load of bollards!

If you go to the Whitehall area of Westminster, you can play the very easy game of "spot the government building". The clue is that they all have large black bollards or sections of wall in front of them (such as Whitehall). These bollards are not just stuck into the ground, they are socketed in huge buried foundations and are of a construction which would stop a pretty large truck bomb from getting through. 

Same location, but from a child's point of view - they will not be
visible to drivers and anyway, they visually separate pedestrians from
motorists which could lead to some not expecting people crossing
where they want.

The science is concerned with the distance between the bomb and the target. A bomb shockwave expands radially, but the energy quickly decays as it travels away from the point of the explosion. Therefore, the further away the bomb can be kept from the target, the lower the impact - in fact, the energy dissipation is nonlinear with distance. So, for every metre travelled between the blast and the target, the energy is far less than the previous metre.

The leaflet also explains that in order to meet "security requirements", the "air gap" between the bollards (the empty space between them ) needs to be 1.2 metres as a maximum. The findings of observation and literature reviews suggest that with this gap, there is a "minor effect on pedestrian convenience". Yeah, right.

There is counter-position to all of this security in that a would-be terrorist won't bother trying to attack a fortified location, he would go for a "soft target" anyway. So, on the off-chance that a government building might be attacked, pedestrians have to put up with reduced footway widths, bollards in the middle of pedestrian crossings and obstructions to their free movement. Oh, I also think that these phalanxes of bollards look awful and I wouldn't like to clip them riding a cycle or motorbike.

Pedestrian and cycle bridge over Rotherhithe New Road,
South Bermondsey (Stubbs Drive). One central bollard might have
been enough, but they double up as sign posts.

Bollards can be useful in situations where unauthorised or undesirable vehicular access needs to be prevented. A good use is on those pedestrian and cycle links which can be used to create filtered permeability through an area, but where there is a risk of people trying to drive through the gaps.

Thought should be given on the layout and gaps between the bollards as it is very easy to render a nice little cut-through as useless to cyclists, mobility scooter users and people using pushchairs.

When being used to prevent access, bollard spacing is critical, although in some cases, it might be best not putting in bollards first and then seeing if unauthorised access is an issue. If being used to stop access to a bridge, then width is important as a vehicle might cause a structural failure.

The table gives widths of some popular small cars (excluding wing mirrors as bollards are often lower). I normally design for bollards being installed to leave a gap no smaller than 1500mm to guarantee no access for vehicles, although one can go a little wider in practice as a driver would have to line themselves up perfectly and drive with no errors for a slightly wider gap.

Where designing for cyclists, remember that handlebars on a hybrid or a mountain bike will be around about 750mm across and about 1000mm above the ground and so the gap is important and keeping the bollard lower than the handlebars might be helpful. Do take care that bollards aren't so low as to be missed by pedestrians and cyclists and they will always be an issue for blind and partially-sighted people.

Caernarfon town centre. The conspicuous carriageway gives way to
a single-single surface, shared space. Are all of those bollards really
needed?

Aside from the ant-terrorism use set out earlier, bollards are also used to stop vehicles parking on the footway or to provide separation between traffic and pedestrians.

This is an often used treatment to stop vehicles parking on the footway and so there is no need to place them at close centres as one would to prevent access. For most situations, bollards at 5 metre centres will be enough as most drivers in most vehicles will struggle to park between them. If you are that worried, 4 metres centres will be fine.

Using bollards this way can stop drivers casually bouncing up onto the footway so go into a shop thus protecting pedestrians, but also prevent the footway being damaged. It is a difficult judgement sometimes as often, a lack of enforcement means that driver behaviour is never challenged and bollards are needed. Of course, in a busy town centre with plenty of enforcement, it might be better (visually) to strengthen the footway by the carriageway edge and accept the odd bit of overrun. Whenever a bollard is used this way, it will be set back from the kerb (to stop it getting hit all the time) and the effective footway width is locally reduced. With the Great George Street example, though, a 500mm piece of footway has been lost all the way along due to the close spacing. 

The other option is to use some other street features to do the same job, such as trees, bins, lamp columns and cycle parking hoops. This is the kind of detailing which can take time to get right, but if we use the principal that everything installed on the street should do a proper job, then things will normally work out fine.

Keep left everyone!

The last type of bollard I want to cover is the "keep left bollard". Again, seen all over the place, it is a bollard with a circular keep left arrow used to tell drivers (and riders) to pass to the left, not doing so is an offence which risks a £30 fine (not much, I know).

They come internally lit, externally lit or reflective and there is various bits of regulation which governs how they are used and how they should be lit. There is no legal requirement that that must be used, just when used, used right.

They can be seen at pedestrian refuges, crossings and at traffic islands. They also come in keep right flavours and pass both sides (not very common). Keep right bollards are used wrongly where an island splits cyclists from vehicles. The sign applies to cyclists and in this case they should be blank-faced and probably sensible use of road markings to keep people in the right place.

So, there you are. Don't use bollards unless you need to and if you are using them with signs, make sure the signs are correct. It's not rocket science you know!