Saturday 8 August 2020

Low Traffic Neighbourhoods - Injecting A Little Honesty

I'll say from the outset that I am a supporter of Low Traffic Neighbourhoods (LTNs) and as a result, I am trying to overcome my confirmation bias when engaging with people who do not support them. However, I don't think there's enough honesty coming forth from some of the objectors.

For those who don't know, low traffic neighbourhoods are areas which maybe take no more than 15 minutes to walk across and from which through-motor traffic has been removed using modal filters to create a system of filtered permeability (I've written a whole guide to it for City Infinity). They are an integral part of the Sustainable Safety approach pioneered in the Netherlands and can be seen all over the world.

In the UK, they are a hot topic at the moment, but they have been around forever such as this example from Leicester which has been in for so long, the trees within it are mature;
LTNs cannot transform places on their own; main roads need dealing with to make walking and cycling safer along them for the simple reason of that's where many shops and services are located. However, LTNs are fundamental part of urban traffic management policy (in the widest sense) in places which try to give people genuine choices about how they travel their shorter trips.

Some designs of filter do permanently remove a section of road from motor vehicle access because it's genuinely surplus to requirements and nobody needs motor access. Some prevent motor vehicle access some of the time (school streets and pedestrian zones for example). However, the vast majority of designs do not prevent motor vehicle access at all, they just stop people driving through the area and out the other side. 

In the photograph below taken in the Vauban neighbourhood of Freiburg, Germany, you can just make out a car parked in the street. There was a guy vacuuming it and so he needed to be close to his home to run out a power cable. You cannot drive through this neighbourhood to get somewhere else (the main roads are for that), but you can get your car to your home to clean it in the same way that a taxi can drop you off there or maybe a supermarket can deliver some shopping. As a result, the street is quiet.

Here's a residential street in Copenhagen. Here, people can park their cars and their cycles. There are no cycle tracks here, but the traffic management has been designed so that the only people who need to be here either live here or have business here;
Low traffic neighbourhoods can also benefit town and city centres. Here we have Luxembourg City which has plenty of motor vehicle access, it's just that it's managed. Some areas have time restrictions, some don't, but the arrangements make it undesirable, if not impossible, to drive through and out the other side. People walking and cycling can go everywhere.
Personally, I think that the whole idea is wonderful and these places are almost always lovely to walk around and safe to cycle through. But of course, we know that there are people who disagree with the approach and that's fine.

What I want though, is to get under the skin of some of the objections. Now there are people who need to drive or be driven - and I really mean need. A LTN won't stop this, but depending on where they live in relation to a proposed filter their preferred route may well be impacted by a scheme. Their preferred route may have been the shortest route to their destination (I'll come back to that) or it's the easiest in terms of congestion or a particular junction. 

The issue of distance is interesting. There's a scheme being planned in London where somebody has commissioned a report to prove that an LTN will mean people have to drive further. Have a read for yourself if it takes your fancy. The LTN uses a series of filters to create a series of "traffic cells" which are all accessible by motor vehicle from the (main) roads circling the LTN, but you can't drive between cells without going back out onto the main roads. The report uses a simple Excel sheet to "prove" that the LTN will increase driving distances from each cell to a series of destinations on the boundary roads.

The mathematics appear fine, but they simply show a before and after distance between each cell and each destination and with that, the cumulative distance between each cell and destination is longer. If you think through the logic, then numerically it has to be the case because the filters stop people driving through the LTN. If you need to drive and your destination is beyond a filter, then you are going have to go the long way round. This report gives a mileage of 32.36 miles for "before" and 49.11 miles for "after" which is a 52% increase and is presented as such for the people in the LTN.

The problem with this type of analysis is that is doesn't present the entire picture. As I mentioned earlier, LTNs are maybe a 15 minute walk and so driving from one of the cells to any point on a boundary road is a short distance and so I have to conclude that those using this as "proof" against filtering actually want to maintain the ability to drive short distances. If you were driving a longer distance, say 20 miles, then the increase at the start or end of your trip (coming home), depending on the route you were taking could be longer than the no LTN condition, but it's a small percentage of that 20 miles. The other problem with this approach is that it simply doesn't model each choice of people person living in the LTN and it doesn't model the choices of those who did cut through.

I don't want to dwell on this one scheme and the piece of analysis, but we should widen our thinking beyond people who need to drive to people who want to drive. It may be that under normal circumstances they drop off a member of the family somewhere as part of their longer drive to work. If the LTN is substantially increasing their mileage in percentage terms, then their trip is already short and in fact they and their family member might be nudged enough to try walking or cycling - yes, LTNs do make driving short journeys less convenient (that's a nudge feature as well as making things safer). You might see the same people reducing the car-based trips to the large supermarket in favour of a bit more local shopping. that's good for them and the local shops.

For the people in the LTNs who need to drive, as well as removing the people who were driving through the area, we've also removed some of the people who we've nudged out of their cars which means that we'll probably reduce the demands on the boundary road junctions which will make it easier for those who need to drive (or be driven) to get in and out of their traffic cell. It's obviously more complex than that because we're also concerned about the impact on boundary roads and indeed other adjacent places without LTNs. In traffic modelling terms, this can be an issue because it can be difficult to model behaviors. 

Many models work by "traffic reassignment" which simply means that if you stop it flowing in one place, it will divert elsewhere, like water. Look at how sat-navs work, a road is congested ahead and so a sat-nav re-routes you somewhere else. The problem with this is traffic is more like (but not precisely) a gas because it can expand or contract depending on what's happening in capacity terms. Behaviour will show is that the potential short to medium increase in traffic on a boundary road might be enough to make some people stop making their trip. For example, someone driving for an hour might be at the very end of their threshold and another 10 minutes is enough to get them to switch to the train or stop making that trip (which may well have other consequences way beyond modelling).

An LTN will change traffic patterns, and in the short to medium term, we may well see an increase in traffic on boundary roads. We might also see patterns change and some people start using other residential streets a bit further away because it might be easier than going on the boundary road in question. That is an issue which people in and around a proposed LTN may very rightly be concerned about in terms of congestion, pollution and an increase in road danger and something which should be acknowledged, although from a traffic reduction point of view, it can't be done by making changes to main roads in isolation because that will push people to drive through local streets that are not filtered. Unless you've the resources to do both at once, LTNs should be delivered first.

In the long term people will adapt to the new reality and there is only so much capacity available and so things will have to find a level again. The skill there is having a regional approach which tackles longer distance car trips in urban areas which are a detriment to the wider community. Space should be given to walking and cycling on main roads, destination parking should be constrained, buses and trams should be given priority and so on. As well as making it harder to drive, we make it easier to travel by other means and those who need to drive can do so more easily, or at least it's no worse than before.

I think the other problem in the whole LTN debate is around whose time do we value the most and who gets a say in a scheme. One of the big problems we have with UK traffic management is the law creates a playing field heavily skewed towards driving because the general approach is for people to do what they want unless limited by law (national speed limits or local traffic orders). As soon as someone looks an putting in an LTN, they are immediately impacting the long established status quo. At a societal or cultural level we also have this whole area of thinking around people only having worth if they are going to work or driving. Imagine someone who walks their child to school and then carries on to care for a relative or maybe doing some voluntary work - do we price them into our economic models?

Do we consult children about LTNs, or do we listen to the well organised and well motivated people (whether for or against)? What value do we put on children being about to cycle to meet their friends rather than being driven (independence for the child and parent). What value do we put on an older person who can invest in an e-bike to get to their shops because the LTN gives them a safer route and some confidence? In fact, what value do we place on those local shops where people on foot spend the most money compared with retail parks? The matter of improvements for well being and society are hardly discussed.

I started this post challenging objectors to be truthful in their motivations, but I'll throw that over to people who support LTNs too. Acknowledge the points that people might have and where there are genuine issues thrown up, work hard to understand them and to try and solve them. However, when someone is projecting their views onto others or they are being circumspect then firmly challenge them. Equally, if you are against an LTN (or any scheme) because it will impact on your ability to drive where and when you like, then please be honest about it. I will disagree with you, but I will at least respect your position.


  1. Great essay. I think a typo here: "can be done by making changes to main roads in isolation". Should it read "can't"?

    1. Yes, thanks. My typos always seem to be key ones like this!

  2. Main issue is lack of consideration for elderly/disabled who may not have a choice if there are car dependent. Also, as seen with the Bowes LTN, places of worship will become difficult to access, so shall people stop practicing their religion?
    Very interesting to note that no impact assessments seem available to address these concerns. Clear air for all, consider an inclusive approach. Sort the pavements out

    1. If people will stop attending church, mosque, or synagogue (for example) simply because it is more difficult to drive to, do they really a believer, or is their true religion the car?

      I attend a church that I would be quite happy to see the road in front pedestrianised.

  3. Main issue is lack of consideration for elderly/disabled who may not have a choice if there are car dependent. Also, as seen with the Bowes LTN, places of worship will become difficult to access, so shall people stop practicing their religion?
    Very interesting to note that no impact assessments seem available to address these concerns. Clear air for all, consider an inclusive approach. Sort the pavements out. An indirect route for someone dependent on car, has several other issues of which one is incontinence. A 10 minute direct route which may take an additional 20 minutes if not more (depending) on traffic means, someone with incontinence cannot get home quicker.
    NHS workers conducting home visits, have increased journey times, hereby potentially reducing number of visits a day, reducing productivity and essentially wasting time sitting in traffic.
    Emergency workers, some have not been able to gain access into roads which now have filters, thus losing chase to criminals, ambulance workers having to walk to person.

    1. Oh look an anonymous comment bleating the whataboutery, well what about the elderly/disabled who can't drive? Are they not allowed to have a safe environment to get about or do you only consider those who drive? I myself don't drive, so I prefer a quieter road for walking on crutches or to cycle along. And using the emergency services as an excuse not to do it is just sad, they are included into plans & will know they exist & how to work with them. Filtered roads are not a new thing & a filtered road is still accessible, just not a rat run for those who don't live on those roads who's only concerns are their own selfish need to get where they want & not care of the impact of those who live on those roads.

    2. What actual research have you done, or read to reach those conclusions?

    3. An interesting note about the emergency services that has sprung up as a result of the Northfields LTN in Ealing.
      Whilst the police and fire brigade are considered as emergency services, the ambulances are considered as essential services.

      Whilst from the outside this doesn't appear to make much difference, one of the problems that has emerged is that Police and Fire service vehicles are equipped with the necessary FB keys used to unlock barriers and bollards whereas ambulances aren't.

      In Ealing at least, this appears to have been overlooked both by the council and the London Ambulance service, whoops, meaning that at first ambulances couldn't get though the bollards and because their satnavs had not yet updated didn't seem to know how to get around the modal filters.

      Luckily this has now been rectified and the council has sent the LAS some keys.

      Small booboo, but it goes to show the validity of that old cliche about haste and speed.

  4. That is a very well written report As part of a keen cycling family I welcome a shift towards cycling as a primary mode of transport. I do however think that each neighbourhood should be treated on its own merit. A detailed analysis should be carried out before implementation and that should be available for all to see. Residents are likely to be suspicious if the data presented does not appear to be factual or worse still if there is none at all. The group who is behind the planning also have be beyond reproach otherwise trust can be lost between the residents and the planners. Its important to not look like a bunch of mates meeting in the pub drawing up silly plans. Furthermore there should be some kind of way of demonstrating that the scheme has worked. IE monitoring pollution levels before and after, traffic levels before and after. Take into account 'traffic evaporation from modal shift and unmade journeys' footfall for business, pedestrian usage, travel time, but do this before starting the project or else you could look again unprepared or unprofessional. I believe that Waltham Forest is a good example of how this kind of project should be done. They have pollution data going back to 2007 and present 2019 data. (To be updated next month) and implemented it with full consultation. Resistance to these schemes is likely if there does not appear to be clear strategy. There cannot appear to be any bias toward any individuals and the planners must not appear to be greedy in terms of what they want to achieve.
    By the way, which project are you involved with and have you done this type of analysis?

    1. On the subject of NHS Community staff, in my experience the NHS seems to make it is difficult for Community staff to NOT use cars, when some would be quite happy to use a bike.

  5. It is interesting to see that despite what has been said above the main concerns expressed against LTNs still assume that most people will still need to use a car for local journeys. Is it not possible these days to attend a church by walking or cycling, could some carers not travel by bike, or some local deliveries be made by bike? Perhaps some people are scared of finding out just how easy some local journeys can be either walking or cycling.

    1. I cant disagree with that but how do we know if a neighbourhood is not doing that already? Are we not making assumptions about peoples habits?

  6. I'm not yet in my eighties - but as a Crohn's colitis survivor, bike saddles can be helpful to counter spasms. We are all different; if we suffer incontinence we are usually actively managing outcomes. Pads and such. Few public facilities. Driving with urgency is a recipe for disasters?

  7. You appear to be disregarding the analysis done on the impact of LTNs by this individual. However there is a total absence of any problem statement from councils backed up by data. This causes confusion as residents are unaware of what the problems are and thus don't believe a 'solution' is required. That combined with lack of consultation and only giving 7 days notice to implementation of the trial has caused anger in many boroughs.
    Landing change of any kind needs proper change management. The council should be engaging their stakeholders (residents), stating what the problem is... Giving them the data to support that along with a clear line of sight to the steps that will take place over a certain period of time.
    Picking holes in people's analysis is fair but only when you can come back with hard facts and figures to contravene.
    I'd welcome a professional approach in my Borough. Unfortunately that hasn't happened to date. It feels draconian, arrogant and 'dataless'. Spouting theories about other countries in the absence of data on the borough being impacted is amateurish. Case studies are interesting but can be like comparing apples and pears. Why can't the councils give proper problems statements and data on the impacted boroughs. If they don't have this, how can they measure success. The success criteria needs to be set first, otherwise it simply cannot be measured.

  8. One more persuasive argument I've heard against them is the benefits on the boundary roads. Bluntly put the LTN pushes traffic off the roads where the wealthy (bigger, more polluting) car owners live and onto the main roads where the less well off non-car owners live.
    My view would be that even if the benefits are unequal (95% traffic reduction on minor roads and 5% on main roads) it is still a benefit to all. But how can we share the benefits more equitably?

  9. I'm broadly in agreement with LTNs, although as a carer, I do have to say I worry about the impact on some disabled people. You say

    "...someone driving for an hour might be at the very end of their threshold and another 10 minutes is enough to get them to switch to the train or stop making that trip."

    That's where the concern comes in, especially in London where relatively short trips can take a relatively long time.

    Of course there are many disabled people who don't use a car, or who can use an alternative, but those most severely impacted often can't, and it's those people (and here I hold up my wife as exhibit A) who are the most severely impacted by that extra 10 minutes.

    I have to say, what makes things worse, is the whataboutery from many LTN supporters (see Wolf above) who seem to think it's acceptable to ignore disabled people's concerns, or in the case of a recent Twitter exchange with one of Hackney's councillors about an increase in taxi costs for disabled people given their longer journeys that those who benefit most (disabled people) should pay most.

    I know that all and sundry are playing the disabled card, and seeking to use it as an excuse to maintain the status quo. And I'm sure that's as frustrating for LTN campaigners as it is for the disabled people, their families and carers whose voices are being drowned out.

    What I'd ask is that planners and campaigners stop, listen, and then go the extra mile to make sure genuine concerns are addressed, and suitable solutions found, that might be as simple as adding extra disabled parking at relatively close local destinations so that disabled vehicle users have a higher degree of certainty that they won't be orbiting LTNs looking for a place to park, or allowing registered vehicles the same access through camera controlled modal filters as emergency vehicles, or any number of other creative solutions that would allow what must surely be a very small percentage of vehicle users continued use of the vehicle that goes some little way to allow disabled people to enjoy the same level of independence that the rest of us take for granted.

    Hope that makes sense.


  10. This is a good article. But I think it misses something. In my area we have an LTN that we were given 6 days notice of, and were informed that consultation would take 18 months after it being installed. Some of the social media commentary has portrayed objectors to it as ‘anti-LTN’. However, I haven’t met anyone who is ‘anti-LTN’. I have met many people who are anti the imposition of an LTN without sufficient prior consultation of the neighbourhood, That’s a different thing. I’ve also met many people who are happy to have an LTN they don’t particularly like/isn’t convenient to them, if they felt they had been part of a prior consultation. So I don’t think it’s that simple. If Council’s spent a lot more time consulting and trying to build consensus or in getting people to understand and compromise, they’d get much more buy in from all residents. At the moment, though, our LTN is resulting in fractured community relations which are destroying the area far more than an LTN ever would.

    1. There's too much misinformation out there and the story gets constantly twisted. The process being used is the experimental one where the installation *is* the consultation - it allows people to see and feel the changes and in my view, it is far more useful than just drawings. You mention consensus, but again, in my experience there is always a noisy core of objectors who scare other people fro talking - I've been there at council meetings and site meetings and seen how they behave and it is intimidating to those who might otherwise have something to add.

      In my experience, lots of noise when consultation starts before anything is tried constantly kills schemes off. If they really are bad in practice, then people will have the first 6-months to make objections. The 18-months is the maximum length of time the scheme can be in place without a decision being taken on implementation.

      More on the process here

    2. Councils will simply ignore objections. That much is obvious.

    3. Councils will simply ignore objections. That much is obvious.

  11. All LTN's in our borough have just been scrapped after vocal opposition from some residents. The problem was this point you mentioned:

    "An LTN will change traffic patterns, and in the short to medium term, we may well see an increase in traffic on boundary roads."

    Main roads were already at capacity, the LTN's forced some residents to take round-about routes (e.g. no right turn so have to go up the road, turn around and come back down) and pushed more traffic onto those main roads. This caused total gridlock and it was taking an hour just to go a few hundred yards down the road. This meant that those who genuinely needed to drive were unable to get around.

    The problem is that the council scrapped all schemes before this bit happened:

    "In the long term people will adapt to the new reality and there is only so much capacity available and so things will have to find a level again."

    I spoke to a neighbour who complained it took them 45 mins to drive to drive to the gym (less than a mile away), this person was fit and well and owns a bike but drives short journeys every day because, until now, it has been the most convenient way to get around. The penny didn't seem to drop that it would have been quicker to walk/cycle/run as they got back into their car and did the same again the next day. So anecdotally, it seemed like the shift didn't happen as the scheme wasn't given a chance to work, or perhaps active travel is so unappealing due to poor infrastructure that people would rather sit in a traffic jam.

    The trouble we now face is that LTN's have become toxic as residents have only experienced the downsides and not the long term benefits. Also, pro-driving residents have found that if they complain loudly enough about the council will concede with very little resistance.

    Would love to hear of any experiences of LTN's being successfully implemented with "the trial is the consultation" approach, what could our council learn from others who have managed to process better?

  12. Appreciate this is a super late comment on this essay (it's a good read) but why should people living in LTNs be allowed to own cars (beyond disability needs etc)? It seems completely ridiculous that in all the shiny press pics "low traffic" neighbourhoods there are solid banks of cars parked on either side for the length of the entire street!

    1. This is the behaviour change element. There is data to show that LTNs are creating a significantly significant reduction in car ownership which runs at a higher rate than just active travel infrastructure alone. At least in London, I travel through plenty of non-LTNs in the central area which are wall to wall car parking, even though public transport in those places is amazing.

      The key here is to start taking away parking spaces as Hackney and Waltham Forest do as ownership falls and convert to cycle parking, pocket parks, raingardens etc.