Nonsense Travels At 25mph

Anything which challenges UK dogma on what or who highways are for is often met with derision and in our current post-fact thinking of the world, emotive nonsense travels far more quickly than rational facts or critical thinking.

This week, I came across a website which concentrates on plans in London to build a so-called cycle superhighway through Chiswick in West London with the rally cry "ditch it or switch it". The consultation for the scheme closed in October last year, but one of the boroughs involved, Hounslow, has said that decisions will be put off until the summer, partly because of the London elections in May and partly because of issues raised about the Chiswick High Road section.

Anyway, that will have to run its course and I want to respond to the comments made on the "ditch it or switch it" website, although in truth, you can copy and paste this kind of sentiment into any scheme where streets are being proposed for rebalancing. It doesn't matter if you are talking about a single zebra crossing which "takes away people's parking" or a transformative scheme such as CS9. The key claim which caught my attention was this;

"The way things are currently, CS9 will destroy Chiswick High Road. It will make it far less pleasant to shop. Buses will be delayed. Traffic will crawl along spewing fumes. We will lose trees and the tables and chairs outside cafes. Pedestrians won’t be able to cross the road very easily. Our local independent shops will lose business. Exactly who in Chiswick will benefit from cyclists whizzing past at 25mph."

How was this particular speed picked - was it from design guidance? In design terms, we will be talking about a "design speed" which then (through mathematics and physics) translates into things like stopping sight distances, the radii of curves and bends, traffic signal timings and so on. The design speed is not going to be the speed at which most people will be cycling. Perhaps we can look at it more like a "maximum safe speed", or a speed within which most people will be accommodated safely.

The Design Manual for Roads & Bridges in Interim Advice Note 195/16 suggests;

Well, 40kph is is 25mph, but a 3% gradient is 1 in 33 - for every 33 metres travelled, one drops 1 metre - that is a pretty steep hill. The other figures range between 12.5mph and 18.75mph. Remember, this is a design standard for trunk roads and motorways and therefore anything designed to this will probably be rural. 

These design speeds provide lots of margin for error and will rarely be applicable in an urban situation. Chickwick High Road does not have a gradient of 3%, it's not rural and so 25mph is never going to be a sensible or even an achieveable design speed. Of course, the carriageway of Chiswick High Road is 30mph, but driver speed never seems to feature in the concerns of those who are against providing cycle tracks.

In the creaky and out of date Local Transport Note 2/08, we are provided with some design speed advice;

So, the guidance talks about a design speed of 20mph with an average speed of 12mph. The point about momentum is an interesting one because with the "traditional" UK approach of bolting on cycling to walking space, we end up with side roads and obstructions impacting on the flow which one would otherwise cycle at. It also reinforces the margin of safety I mentioned about.

They look the part of "fast cyclists", but they are simply
not going to be able to maintain a Tour de France speed.

OK then, who exactly cycles at 25mph? In 2014, I completed the RideLondon London-Surrey sportive. It was the year which got cut back to 86 miles because of a storm. Including stops, my average speed for the 86 miles was 11.12 miles per hour. On the first 17 mile stage from Stratford through Central London, my average speed was 16.19mph. Anyone who has ridden this will be able to confirm that the first part is downhill and the rest is mainly flat, so a top speed isn't going to be getting over 20mph very often, unless one is riding a full-on racing bike and knows how to use it!

Racing bikes, training and closed roads are still not going
to be able to get most people cruising at 25mph.

RideLondon is on closed streets and even the most amateur fun rider (like I was) is going to have to have completed some training to be able to tackle it. There are going to be people out there who can top 25mph. People such as Chris Froome who averaged 25.47mph in the 2017 Tour de France. But hang on, we are talking about flat West London, not the hills and valleys of France. That's the thing about averages, though, they smooth the numbers out and so while our Chris might have been blasting down some hills, he would have been crawling up a few too.

25mph for people using cycling for every day transport is demonstrably nonsense. It doesn't happen and it is disingenuous to suggest otherwise, although it does rather suit a particular style of narrative. Personally, I cruise (average speed) at about 10mph on my commuter bike which is a big heavy, upright hybrid. If I am on my tricycle, my cruising speed is about 8mph. It is a long, long way from 25mph.

People feeling safe won't have to worry about keeping
up with drivers. They can relax and take it a little easier.

There may be fears about how cycling may change an area because of the way in which highway space needs to be rebalanced. If people stuck to that, then they would perhaps be a little bit more honest about their fears. Perhaps some people who don't cycle can only see the young white male cycling on their streets at the moment. This small group of people will be more likely to be moving towards the higher end of the design speed, but being on the carriageway, it's a defensive tactic. This is what you get if you design for cycling as a bolt-on to driver space.

A group of tourists on a safe cycle track. They are seeing
the sights, they're not a racing team.

As with designing streets for driving, we can influence the speed and behaviour of people cycling through design, especially where we need to give clear instructions on how people should deal with the interaction of others such as the approach to a bus stop. However, the key difference between cycling and driving is that the strength, power and endurance of people cycling varies hugely, whereas the motorised transport essentially levels these differences.

A sedate commute, enabled by the protection. This chap
might be your target customer on a rebalanced high street,
rather than the people driving through at 30mph.

What this leads to is where cycling infrastructure is well designed and attractive, then everyone can use it and above a minimum flow (which will depend on location), the "slower cyclists" will help influence the speed and behaviour of those who are more capable of nudging the higher end as they ride. In short, good infrastructure creates the conditions to enable a wide demographic to cycle and in turn speed and behaviour is moderated.

Bridge Over Troubled Water

While the Foreign Secretary, Mr Johnson, was going on about building a bridge to France this week, the RAC Foundation said that almost 3,500 bridges in Great Britain are substandard (2016/17 data).

"Substandard" relates to bridges which don't meet the 44 tonne classification for the maximum lorry weight (weight of fully laden vehicle) which comes from European legislation aimed at ensuring compatibility across the area. As usual, there are local variations in how this is implemented and it doesn't mean that 44 tonnes is the maximum allowed. In the UK, for example, there are rules about moving heavier vehicle/ load combinations, but that's another story.

There will be bridges which have weight restrictions (generally 3, 7.5 or 18 tonnes) which are perfectly adequate for their local situations (because larger vehicles are not wanted in the areas concerned) and there are plenty of bridges which have had some interim measures applied to them which means they still don't meet the 44 tonne classification, but they are safe enough. 

For example, the photo below is of St Augustine Road in Leicester which is carried over the River Soar by the West Bridge. As far as I know, there is no weight limit on the bridge, but there will be an issue with the footway or parapet (the edge of the structure with the balustrade) because of the use of containment kerbs to keep vehicles off - it's a classic interim measure which can often stay in place for decades!

Given that most of the top ten of councils with the most substandard bridges have huge rural areas, it's not a huge surprise as this will include places which are off the beaten track where 44 tonne lorries either won't be going or where they are not welcome anyway!

The RAC Foundation estimates that the cost to bring the substandard bridges back up to standard is £934m and the wider maintenance backlog on our bridges is around £5bn. With my caveat about the need to bring everything up to 44 tonnes, this is another significant amount of money. 

Taken with the £12bn backlog for carriageway maintenance (and that's just England & Wales), it is a timely story that when politicians start showboating about shiny new things, they always seem to ignore making the best of what we already have.

Kerb Your Enthusiasm: Bus Stop Accessibility

I'm currently doing a lot of thinking about kerbs. This partly because I am obsessed with them (they are bread and butter for highway engineers) and partly because I am starting to write a guide on their use.

The guide will be published through City Infinity in the coming few months, but in the process of undertaking some research, I thought it would be nice to concentrate on how kerbs can be used at bus stops. This blog is a kind of follow up to my first kerb blog post which has also spawned one on stepped cycle tracks; plus it helps me get my mind back into writing about details rather than some of my ranting of late. 

So, why are we interested in kerbs and bus stops first off? Well, modern buses are low floor and that means that the majority of the lower deck will be at a single level to enable people using wheelchairs and pushchairs to access services and the floor of the bus is also as low to the ground as possible. Actually, most people will zero in on wheelchairs and pushchairs, but as is always the case with accessibility, improvements for those who need them most will be of benefit to everyone, so low floor buses are good for visually impaired people, people who use sticks or other walking aids and people with balance or dexterity difficulties.

Having low floor buses is one thing, but in order for them to be accessible, the bus stop environment needs to be compatible with the vehicles. From a kerbnerd point of view, this means setting the kerb height correctly to be compatible with low floor buses. In practice this means the kerb in the passenger loading area is probably going to have to be set higher than is usual. The nominal kerb "face" we use generally will be between 100mm and 125mm; this is to say the amount of kerb sticking up above the surface of the carriageway. The aim is to have the threshold of the loading door(s) to be within 200mm of the kerb.

In Inclusive Mobility we are recommended to consider using 125-140mm kerb faces, although in some cases, something a little higher might be appropriate. This guidance is a little long in the tooth in part and while it hasn't been updated, bus technology has been and if a kerb is too high, then it could create compatibility issues with the vehicle. As well as having step-free lower decks and low floors, modern buses will also have suspension which can "kneel" - to drop the whole vehicle down and a wheelchair ramp which can be deployed from the front door if single door operation, or rear doors if two door operation (bendy-buses will generally have three doors, so the centre doors in that case).

Here is a video (not mine) of a wheelchair ramp being deployed;

There are suppliers of special kerb units with perhaps the most common being the Kassel kerb from Brett Paving which comes with 160mm faces where kneeling buses are used or 180mm where they are not. Increasingly, the 180mm version is becoming obsolete with the most modern bus designs.

Above, is a photo of a Kassel kerb insitu. It's a short length and so will be used for single door operation. Note the textured top surface to reduce slip risk and the curved profile to the area between the flat part level with the carriageway and the upstand (which is raked back away from the vertical). The photo below shows a longer kerb length which would enable multi-door buses to stop (and multiple buses).

To show there is no bias, Marshalls also produce a bus stop kerb which comes with a separate channel block. Used together, the height of the kerb can be varied to fit the local requirements and the channel block has bumps to help guide the bus driver into the correct position.

We don't have to use special units as the standard half-battered kerb does a fine job. Even though we generally use them between 100mm and 125mm, they can be laid to give a nominal 140mm upstand with ease. Indeed, that has been the choice for years in my day job where we have upgraded a few bus stops to be fully accessible!

Making a bus stop is not just about the height of the kerbs. A crucial element is for the bus to be able to be driven tight into the stop in the first place - a bus stopped way out from the kerb is simply no good. To keep the stopping position clear, we are going to need a parking restriction of some kind. The best answer is to use a "bus stop clearway". This has a wide yellow line along the edge of the carriageway and a dotted yellow line marking out a long rectangle; often called a "bus cage". The layout of a bus stop clearway is prescribed in the Traffic Signs Regulations & General Directions 2016;

For a bus stop clearway to be enforceable, it needs to have an upright restriction sign which is a familiar black writing on a yellow background, also a traffic sign prescribed in the TSRGD16. Interestingly, however, bus stop clearways do not require traffic orders, although the Department for Transport suggests that consultation should take place before a decision is taken on their introduction;

The "clearway" restriction means "no stopping" except buses and taxis (not minicabs) for boarding alighting. Therefore, they can be controversial if installed outside homes and businesses because of complaints about parking and loading impact; however something has to be prioritised and a bus stop without a clearway is more likely to be abused by drivers.

The photo above shows what happens if there is no clearway. The red car is stopping the bus driver getting close to the kerb and they cannot pull far enough forward to have the rear door adjacent to the high kerb of the stop. The dropped kerb to the driveway access means that there is no way the driver can deploy the wheelchair ramp from the rear doors with a low kerb.

The photo above shows a clearway in action. Note the position of the bus stop sign (known as a "flag"). The flag is often arranged to help bus drivers stop in the right position which is with the front wheels of the vehicle in line with the flag. This means the front doors will be within the area of the shelter (if one is provided). Sometimes the stop will be arranged so the front or rear of the vehicle will be stopped in line (for a localised reason) and these are known as "head stops" and "tail stops" respectively.

You will also note from the photograph that the stopping position is towards the far end of the stop and the clearway is quite long. The reason for this lies in the steering geometry of buses with two door operation in that they require a longer distance to pull into the kerb (at a gentle angle) to ensure both doors are close to the footway. Pulling away from the stop requires less space.

The photo above shows the original kerbs have been reset to the correct height and a long enough section has been adjusted to comfortably deal with the bus driver not having to be perfectly accurate in the stopping position. The stop area has also been repaved to ensure it's nice and flat and in the future, it will show the "accessible area" within which dropped kerbs should not be placed - often an issue in urban areas where people want a dropped kerb to serve a driveway or where a developer fails to consider the needs of bus passengers in their design.

It's not just about the kerbs of course, but luckily, Transport for London produced an excellent update to it's bus stop design guidance last year which I'd recommend you read for a comprehensive explanation of the subject.

It's A Network Problem

I've been following the debates around a few of the higher profile "streets" schemes as they go through public consultation and the thing which is striking me most is that the consultations rarely mention the wider network and nor do many of those debating the issues.

Much of the problem (I think) is the way in which consultations have turned into mini-referenda where the public is invited to choose sides with the inevitable loss of the "yes, but" or "no, unless" views which can be the ones to offer different insights. It's also about the nature of the things being consulted on which are often corridor-type projects (regardless of mode) where area projects would be more appropriate.

There are so many examples to pick on, but in London, Transport for London consulted on "cycle superhighway 9" which includes cycle tracks on Chiswick High Road. Those in favour of the scheme describe the existing situation which is hostile towards cycling and those against raising a whole list of reasons, but essentially, they're not liking the threat to the motor-centric status quo (and yes, I am biased). 

In my experience, those against a scheme often have far more to say than those who support and it is easy to see how decision makers are influenced by the volume of objection in terms of noise and points made! However, in these consultations, there are some voices where people are raising genuine concerns about displacement of through (motor) traffic onto side roads, the impact on bus journey times and that loading/ servicing of commercial premises will be more difficult.

There will be people against change and no matter what you tell them, that is their position and effort to try and influence their view is on diminishing returns. People with genuine concerns can be brought along and this must mean looking at the issue from a network level. For example, if we know there is going to be traffic reassignment (at least initially), or perhaps more importantly there is going to be a perception that this is going to happen, then perhaps we should build that into the scheme. 

This is not to say that I'm advocating a position of where we should accommodate everyone's view, it is simply not possible, and with that, it must go back to a conversation about what our streets are for and to for those making decisions (and their advisors) to be honest with themselves and the public at large. With CS9 though Chiswick, some people have said that support protecting cycling, but not in that location. 

Even if you don't know the area, you can easily see from a map, that the alternative is to stick people on the A4 which is not somewhere that space is going to be reallocated or on a wiggly route around backstreets where every modal filter proposal will end up as a mini-refurendum!

Looking at this as a network issue, we must set out our broad priorities for the area. At one end of the scale, we have the A4 which is about getting longer distance (motor) traffic into West London. At the other end of the scale we have residential streets which should not be there to provide capacity for through traffic (although many people would disagree with me there). 

Then we have Chiswick High Road. Like many similar streets in the UK, we have the tension between people wanting to use it like the A4 and people wanting it to be a local street serving the community. The problem is that one cannot ever be fully compatible with the other. If we treat the High Road as a movement corridor, then we are going to need traffic signals at certain junctions to deal with conflict and controlled crossings to give people a fighting chance to cross. 

We are going to need bus lanes if we are to prioritise public transport (we don't always). We are going to have pressure for on-street parking and loading. We are going to have pressure to have wide footways (because it's a shopping street). We are also going to have pressure for the other things like nice street trees, tables and chairs in front of cafes and occasional maintenance and utility works.

By trying to permit everything in places like this which have evolved over many years, rebalancing space towards any one mode (regardless) will have an impact and and unless we think about the network as a whole, this impact will be felt over an area which is why we should think about the area as a whole.

We don't seem to like prioritising in the UK. Many local authorities will have a hierarchy of movement - here's Hackney's which I reproduce just as an example, rather than a critique;

• Pedestrians
• Cyclists
• Public transport users
• Freight distribution (local)
• Car users (multi-occupancy)
• Car users (local)
• Car users (non-local) 

The problem with this approach is two-fold;

1. Having a hierarchy is one thing, applying it is another,
2. It's a one-size fits all approach which doesn't recognise the network approach.

Clearly, we are not going to prioritise pedestrians on a road like the A4 and to suggest we are is nonsense. Depending on what such a road connects, we may not even need to put pedestrians at the top of the hierarchy. For example, if the road has direct pedestrian access every 2km or so, then perhaps we have a cycle track which pedestrians might occasionally need to access (say to bus stops). In that situation, we provide a legible and separated layout where people walking need it most (between the access point and the bus stop) and the rest can be a shared-use cycle track.

In our residential area, we might rightly put pedestrians and then cyclists at the top of our hierarchy, but public transport, freight and non-local car users are not going to feature. Perhaps the hierarchy needs to explicitly mention school children as they may be prioritised above local car users (and to be fair to Hackney, they have schemes where pedestrian zones are in force around schools as school travel times).

If our High Street follows a hierarchy like this, it is not going to be possible to include all users (because space is a finite resource) and so we need to prioritise. Walking, cycling, public transport and local freight must surely be the most important and the ones we can fairly easily accommodate. For private car users, we create a motoring grid to get them to and from the A4 (for example), but if we are to prioritise the High Road for the modes I have suggested, people cannot expect to easily drive along its whole length.

Where we keep trying to accommodate everyone (and fail), we continue with enabling people to drive short journeys and this leads to the regular issues of congested High Road type places and "rat running" in side roads. If we looked at change at the network level and prioritised properly, we would surely be able fairly accommodate sustainable travel modes, make quieter residential streets and also make our High Roads nicer places to linger, while dealing with essential servicing.

The other thing to grapple with is the issue of "we don't have a problem". The best example is where a controlled parking zone is being considered. Those in the core of the area have an issue, but at a distance away, people won't. The problem is, that a smaller CPZ will push the parking issues to the fringe and those who didn't have a problem now do. Rinse and repeat. 

The problem here is properly admitting to those that don't have a problem now that they will and that is why a comprehensive scheme is needed. A streets scheme is no different and only by looking at the network can we foresee what the issues might be and then challenge them head on. If it means we have to be a little slower in design and consultation terms, then so be it.

Perhaps looking at the network will mean that once we decide what we are going to do and how we are going to prioritise (once we have consulted), then we have a plan which we can stick to. We can use temporary materials to rebalance and reclaim space as it allows us to cheaply tweak things if there is an issue, and then we can gradually upgrade an area as funding permits (while noting there will be big ticket changes needed). 

This approach could also align with the needs of utilities and maintenance works. For example, as we apply some concrete blocks as modal filters to protect residential areas from High Road changes, we could have the utilities on the High Road undertaking diversions and upgrades which would take out capacity and so give people the chance to get used to it. At the same time, we implement bus service changes, loading reforms and so on.

Yes, it means more time and planning up front and potentially longer "on site" disruption, but everyone knows the plan and they know the end game. What we can perhaps avoid is putting in a large expensive scheme and then having to go back and retrofit it or the surrounding area to deal with issues which were, in truth, foreseeable.