Sunday, 17 March 2019

A Curious Kerb Catch

I happened to be on Google Streetview earlier in the week undertaking a virtual site visit (a wonderful tool to use from the comfort of the office) where I came across an interesting little granite kerb detail.

The estate I was nosing around was built in the early 1900s and I happened to see a dropped kerb to serve a driveway to a garage;


I reckon it was an original installation, because the garage it serves is of the right vintage for the estate. Back in the day, dropped kerbs for driveways were quite an unusual street feature because there were few cars around and the dropped kerbs around the rest of the estate are almost certainly more recent. In terms of housing style, it may also be that the house served by the driveway predates many of the others.

So why did it catch my eye? Well put simply, the footway is kept at a constant crossfall as it passes the driveway rather than having a dip or steeper crossfall which is so often the case. It also shows thought and a high level of craftship. The 'dropped' part of the kerb line is actually tilted towards the carriageway and the kerbs flanking it are rounded to avoid a tyre-bursting point.

At some point I will get out and visit the site, but my estimate is that the kerb upstand (height above the carriageway surface) is about 60mm and the kerb width is about 300mm - this gives a slope of 1 in 5. Here's a more stylised layout;


Keeping the crossfall of the footway constant makes walking more comfortable than having to keep negotiating dips or steeper crossfalls and this especially helps people using mobility scooters and wheelchairs as well as people pushing prams.

The layout also raises another point and that's about wheelchair users wanting to cross the road away from junctions. Inclusive Mobility recommends that ramps are no steeper than 1 in 20 or 1 in 12 at the steepest and even that is going to be difficult for some manual wheelchair users. However, vehicle crossings almost always get installed with an upstand of about 25mm which is no good for the front wheels of a manual wheelchair and many powerchairs.

With a very short slope of 1 in 5 (over the width of a kerb), I wonder if this is more useful for incidental crossing of the road for wheelchair users than a 'traditional' (in fact modern) approach to vehicle crossing and perhaps there is a wider issue about the fact that we provide pedestrian dropped kerbs at junctions, but rarely provide any along streets, unless a more formal pedestrian crossing is provided. 

In side roads, it is almost always going to be vehicle crossings for informal crossing and so I would be interested in the view of wheelchair and mobility scooter users - perhaps this an an area which needs a lot more research?

Sunday, 10 March 2019

How To Become A Highway Engineer

It's an interesting question for me because I didn't plan to become a highway engineer, it sort of happened; but, for what it's worth, here's how I did it because there are so many different paths you could take.

Thanks to Savage Houtkop for asking;


My journey started back in school where my favourite subjects were geography and craft, design and technology (CDT). Being the second year of GCSE, there was lots of coursework which suited my learning style of research, thinking and practical work. I did OK at GCSE overall and I had an idea that I wanted to design cars - the product design and technical drawing aspect of CDT was part of the reasoning.

I went on to A-levels to study maths and physics because that what aspiring engineers did; I also continued my love of geography to A-level. Things didn't go well and I only passed geography and got an 'N' or 'near pass'. I found the maths at A-level too abstract and I probably only did as 'well' as I did in physics because of the practical aspects.

I was at a crossroads. I wanted to carry on studying, but the mechanical engineering courses I was thinking about during A-levels suddenly became a remote possibility because of the maths and physics issue. Luckily, Hatfield Polytechnic came to the rescue. They were offering a higher national diploma (HND) in civil engineering studies and I had enough GCSEs and my A-level to get onto the course.

The HND was brilliant because there was so much practical application through the learning. Casting and smashing concrete cubes in the structures lab, setting out roads on the field behind the college, comparing drainage theory with reality in the hydraulics lab and so on. In short, we were directly applying the theory, undertaking research and learning ourselves, working in groups on practical problems and seeing how the built environment fitted together. 

I did well enough on the HND to be admitted into the second year of the civil engineering degree at what had become the University of Hertfordshire. I was admitted with quite a few of my classmates from the HND which kept the group ethos of problem solving intact. The degree was undoubtedly harder because there was a great deal more theory and the maths and physics came back to haunt me. I did OK and finished with a second class honours - bachelor of engineering to be precise.

I was now 1995 and I was in the real world and needing to get a job. Luckily for me, I had been studying during recession, but the economy had improved and through a recruitment agency I got a job as a site engineer with a telecoms contractor. The pay was awful and the hours were long. I was assigned a handful of works gangs who laid ducting for cables in the highway, built jointing chambers, bases for cabinets and other associated work. I had to make sure the work was being undertaken safely and to the contract standards as well as measuring up was was built (for invoicing).

However, there was camaraderie with colleagues (all young site engineers) and the gangs with a joint purpose of trying to get the job done. I was trained as a streetworks supervisor, learnt from those doing the hard work and there were highlights such as the site engineers regularly driving in convoy to a local cafe for the weekly fry-up and moan about the job.

I kept my eyes open and by the end of my first year with the contractor, I had secured a job as an assistant engineer with a highway authority where I would be dealing with maintenance work - mainly footway reconstruction and carriageway resurfacing. I learnt a fair bit about highway construction and materials as the highways manager was always keen to try out new methods and practices. I got involved with in-situ pavement recycling, different asphalt systems and a little bit of work to implement small traffic schemes. Some of my best memories were on-site with asphalt crews undertaking night time resurfacing because while busy, they were always pleased to show how all of the kit worked.

I loved the maintenance work, but I wanted to become professionally qualified and the type of work was never going to be of a scope which would get me there, although I did join the Institution of Highways & Transportation (now CIHT) as a member. I needed broader experience and I found a post as a civil engineer with a development company. The work exposed me to some heavy civil engineering design and construction work building roads, sewers, bridges, flood balancing ponds and perhaps most interesting of all, dealing with contaminated land with the possibility of unexploded ordnance! 

Again, I was fortunate to work with a great team and my boss also became my mentor as I prepared to sit my professional review with the Institution of Civil Engineers (ICE) to be admitted as a member and a chartered engineer. Part of the professional review included an interview with two ICE members and part of the interview required me to give a short presentation on some work I had been doing which was in turn based on a written submission of the same. 

Being a practical person, I made a little laminated flip chart of photos and plans of a water treatment lagoon project which I had managed. I also may have raised a couple of eyebrows when I reached into by briefcase and took out half a dozen glass jars with coloured soils and other things in them. I explained that the bright blue streaks in the soil in one of the jars was 'Blue Billy' a particularly noxious substance and the greenish lumps in another were burnt explosives. Looking back, they probably weren't items to be carried on the Tube. I also had a jar with a section of geosynthetic clay liner which is used to waterproof lagoons and landfills, complete with a rusty nail sticking through it to demonstrate its self-sealing properties. I passed in any case.

By the autumn of 2004, my wife and I were expecting our first child and so I decided to move jobs again and found a post with another highway authority a bit closer to home. I was to be undertaking traffic and highway engineering schemes as a senior engineer. Within a year of joining, my boss quit and I went for his job as a principal engineer which meant taking on staff management responsibility and a much wider area of work including development management, bridge maintenance and all sorts of highway schemes.

The work was (and is) highly varied and interesting, but with a backdrop of politics which can be very frustrating at times. In 2011 I had an epiphany - well actually, it developed over a few months. Becoming irritated with sitting in traffic following an office move from the very edge of suburbia into a town centre, I dug out my bike from the shed and became a short-distance cycle commuter. I started to wonder why on earth people would sit in traffic for short journeys (which was previously me). I then realised that I was in a minority as someone prepared to brave mixing it with motors and I became open to the idea of changing our streets to enable people to change how they travel.

Anyone who has followed me for a while knows the more recent history. I started this blog in 2012 in order to vent my frustration and in 2017, I took some tentative steps into freelancing on the side as City Infinity which has been fun. In the last couple of years, I have become increasingly fascinated by how streets and the elements within fit together and how we can make them accessible. I have also been fortunate to meet some inspirational people who have changed my view on how our streets and urban places could work better.

The future isn't written of course and I suppose I have the fun of finding out what happens next, but I'm increasingly hoping that the future will be further away from designing cars as ever.

If you are interested in becoming a highway or civil engineer, here are a couple resources;
I think my overall message is although there are formal routes to becoming a highway or civil engineer, you don't have to follow them. We need a diverse group of people with diverse set of skills and so don't let qualifications or experience hold you back!

Sunday, 3 March 2019

Dual Carriageway Terror

While I was out and about in the week, I happened to be cycling along a dual carriageway (on the path because I didn't want to become innovative jam) when I spied a gap in the central reservation barriers.

The road in question has the national speed limit and it is was patently obvious that many drivers were travelling at high speed. At least from where I was standing, sight lines across to the central reservation were poor and I did wonder if anyone ever crossed there.


The road's origins go back to the late 1920s and in fact the side road you can just see in the distance was cut in two by the road when it was built, so disrupting the network of very narrow country lanes which served the farms on the area. I have had a quick look at historic maps for the area and in the mid-1940s, the dual carriageway still formed a crossroads with the two side roads.

At some point, it was realised that having people turning right onto and from a trunk road was a bad idea and the traffic closed, but in common with countless places, we can still see a remnant of pedestrian access rights where old desire lines are kept with gaps in the barriers.

The layout of the barriers (properly known as 'safety fence' or a 'vehicle restraint system') is such that the pedestrian route means that one walks with their back to traffic in the central reservation because of the barrier overlap. If this was reversed, then it would be possible for a vehicle hitting the barriers to go through the middle.


In CIHT's 'Designing for Walking', Table 3 gives a ready reckoner on the suitability of different types of pedestrian crossing (there are clearly more detailed variables at any given site). I reproduce the first type of crossing above as it has a bearing on this case - I think you'll agree that a pair of dropped kerbs to cross a 70mph road (even in two halves) is a big ask for most people to use as a crossing. There is a DfT traffic count point nearby and the road carries some 36,000 vehicles per day - actually quieter than we might expect for a dual carriageway, but clearly still a large volume.

Looking at the foot of Table 3;


As well as being able to see what the colours mean, we learn that in this type of situation, the only appropriate choice is a bridge or an underpass. 

There is no history of pedestrian casualties at the crossing point and so unless there is ever a proactive programme of reconnecting pedestrian routes, it's unlikely this location will ever be looked at and so it will remain a quirk of history from a time where there were few cars and people would have walked between home and the farm they worked at.

So what? Well, we are still making the same mistakes as we did 90 years ago. Forever pushing for more road space, we still sever walking routes in the name of progress and once severed, they are never going to be retrofitted. For a large road building project, the costs to maintain pedestrian routes aren't costly and the engineering isn't difficult. Still, we seem to be very poor at learning from history don't we?

Sunday, 24 February 2019

Logical Logistics

As most people cannot grow all of their own food and make everything they need to go about their daily lives, we still need to deliver 'stuff'. Back in the old days, we might have used a horse and cart, but these days, we are heavily reliant on vans.

As inclusive cycling campaigner (and logical thinker), Clive Durdle has said;

"Why do we design deliveries like giving everyone a personal sewage pipe to the works."

As we become more dependant on internet shopping and next day (even same day) delivery we might be seeing some shift in logistics. In the Department for Transport Road Traffic Estimates we see that as HGV traffic mileage has stayed relatively static over time, light commercial traffic mileage has exploded, especially in the last few years.


To continue the metaphor, a personal sewage pipe to the works would be grossly inefficient; a duplication of resources and certainly not practical from a space point of view, yet we've vehicles out on the roads which are not filled up. The problem with logistics, and especially home delivery, is that we have so many different suppliers and deliverers that in fact, we have several sewage pipes!

It's a tough nut to crack because people want the convenience of a home delivery and because it only works when they are at home, we also have people getting deliveries at work. Just think of all of the vans circulating - there is no way they are going to be running with full loads.

We seem to have moved (at least in part) from a model where we go shopping to one where shopping comes to us. It's a tough system to redesign because of our high expectations as consumers, the market forces driving down prices (including owner-drivers being paid by the parcel) and the essentially "free at the point of use" model we have for our highways.

Sitting out in suburbia as I do, there will be a few deliveries a day to the people in my street and this isn't too much of an issue because there is space. Of course, add up those deliveries across an area and that's going to be a significant number of vehicles. As development gets denser, we have more residents per square metre, but the streets don't have any additional capacity and so as well as helping drive congestion, problems with those delivering parking badly become commonplace.

So, what can we do? Any discussion about restricting motor vehicles in the UK is met with howls of derision and with commercial operations, we're accused of trying to harm business - but of course the tragedy of the commons argument about road danger, pollution and wear-and-tear on our roads rarely comes into it.

I think that there are a few things we should perhaps think about;

Consolidation
Yes, I know this is already done, but it's a good point to make. Businesses in a common area can club together to use a smaller number of suppliers, using a smaller number of vehicles for deliveries.

It's not just about goods coming in to an area, it's about waste going out. A good example is the work done in London's West End to consolidate waste collections. Residential waste is collected by the local authority, but commercial waste is dealt with by each organisation. The project in London looked to put together consolidated contracts so that as well as greater buying power for the businesses, the number of waste vehicles could be reduced.

Consolidation can also include deliveries being made to places for people to pick up their own goods. For example, Ebay deliveries made to Argos or Amazon deliveries made to a drop box at the supermarket allows people to pick things up rather than a deliverer needing someone to be in to receive a parcel. In addition, as Clive Durdle points out, there is untapped potential for rail consolidation.

Weight Limits
Unless we apply a traffic order to a street, in theory at least, any size of vehicle can be driven along any given street. If we wish to place a weight limit on a street (7.5 tonnes tends to be common), then we will normally have an exemption for deliveries/ access. An absolute limit would ban larger vehicles completely and so prevent deliveries by vehicles over 7.5 tonnes - we could of course write an exemption for refuse and fire fighting, but this doesn't need to go on the signs.

So what, perhaps we don't want larger trucks being used in places where they are really too large. Might this force deliverers to use smaller vehicles as a matter of routine? Do deliveries in trucks heavier being use which are heavier than 7.5 tonnes every run full for residential deliveries? Of course, if you are moving house, then a larger vehicle might be needed, but why not treat this as a planned event (in terms of road space management) where an exemption has to be applied for in order to use a large truck in a small street?

Ban motor traffic
This brings up lots of questions of course, but could be change the balance on our streets by banning all but essential motor traffic. Private cars might need to be stored in a different way; refuse collections might be rethought by using communal underground bins which is collected as and when they fill up;


Do we prioritise on-street loading space over private vehicles? Should delivery systems be organised around neighbourhood consolidation hubs that all suppliers use with the last mile completed by cargocycle?



This is all linked of course to wider arguments on how we plan and deliver transport and spatial planning because it is all linked. Perhaps our reliance on light commercial vehicles was inevitable because of our planning and transport policies which makes some of the good ideas seem more radical than they really are.

Going forward, our current systems are clearly not sustainable and something needs to change, but we haven't even begun to have the debate yet.

Sunday, 17 February 2019

Power to the Little Wheels

With the continued obsession with getting people out of their fossil-fuelled cars and into electric cars, we continue to ignore the short trips that people make every day with perhaps too much focus on commuting.

Despite the 'official' approach of pumping money into subsidising EVs and EV infrastructure, some people are voting with their feet and their wallets and taking control of how they want to travel, rather than continuing to buy into the top down push to maintain an addiction to the car.

The use of scooters is a growing phenomenon whereby the ubiquitous school-run favourite of the nippers has grown up and in some cases, received a battery boost. Scooters are available from the usual retailers for not very much money and even the electric variants are relatively affordable - certainly cheaper than a daily commute bus. Scooters are easy to store, easy to carry onto a train or bus (for multi-stage trips) and let's face it, they're quicker than walking.

Uneven footways are awful for little wheels.

The problem is that our highways are not designed for scooters, and especially not for e-scooters. As far as I can work out, anyone can use an unpowered scooter on the highway (usually along a footway), whereas e-scooters are not permitted because they are (in essence) motor-vehicles. This isn't stopping firms dipping a toe into the UK with dockless e-scooter sharing, although they are limited to non-highway locations such as the Olympic Park in London. Anecdotally, I've heard of employers in city centres purchasing pool e-scooters for employees to help with short trips.

Having small wheels can make scooting a difficult and possibly risky endeavour on our uneven footways (although those with pneumatic tyres and suspension. are a little more forgiving, but it seems to me that proper cycleways would be the ideal place for people to scoot along because smooth surfaces and dedicated space for faster moving people (especially e-scooters) has to be better than using the footway.

We're told that EV cars are coming whether we like it or not and so we have to provide charging infrastructure on our streets to accommodate them. On e-scooters and similar devices, Government interest seems to extend as far as reminding us that they are illegal, mind you, mobility scooter users aren't allowed to use cycle tracks which shows how much the Government is bothered about people who are not driving.

Forget the law, powered mini-vehicles will be
used whether or not the Government likes it.

For my mind, we should be embracing scooters and using them as another reason to change how our streets are designed and managed. E-scooters should be regulated with a maximum powered speed and like mobility scooters, a lower speed on footways; with cycle tracks being somewhere that both e-scooters and mobility scooters can be at home on.

As ever, we face an ever-present choice for local trips, despite the march of technology. We either want people to be out in the fresh air getting about under their own steam (with an electrically assisted boost if that's what they need) or we can carry on helping people drive a couple of miles (so long as they can afford it). Vehicle autonomy can never replace human autonomy and if little wheels can help get people moving, then I'm all for it.