Saturday, 18 September 2021

An Olympic Oddity

This week's post is a hyperlocal issue, but still worth exploring, if nothing else than to try and unravel the thought process a little bit.

The road network for the Olympic Park in East London was, in many ways, over-engineered for the Games themselves. The years of redevelopment and repurposing the site still continue nearly 10 years later. Of course, there were also years of planning and design before the Games which were awarded to London in 2005 which explains why the roads are very much designed to standards and attitudes of the time.

One location is Northwall Road, specifically near its junction with Temple Mills Lane. It's an area I know from long before the Games with Temple Mills Lane snaking through a post-industrial landscape. Northwall Road, on the other hand, is an Olympic-era road, providing servicing to the area. I'm not entirely sure what the long-term plan is just here, but judging from my visit a few weeks ago, I assume it's going to be retained.


So, the curiosity which has recently popped up is a new section of cycle track just set back from the junction with Temple Mills Lane (above). 


The existing 2-way cycle track bends out from
Temple Mills Lane into Northwall Road.

The layout essentially extends an existing 2-way cycle track on the eastern side of Temple Mills Lane across the entrance of Northwall Road and to a walking/ cycling tunnel under the adjacent A12 (below). 


Unfortunately, the layout becomes shared-use within the tunnel which is a shame, because had it been properly extended, it would have met with a 2-way cycle track on the northern side of the A12, recently built by the London Borough of Waltham Forest, providing yet another protected main road into the borough.

Northwall Road itself is currently closed to through motor traffic (it was being used for filming on the day of my visit). There are a pair of short 1-way cycle tracks providing access to and from the 2-way cycle track (below). The cycle tracks are short and provide transitions to and from painted cycle lanes on Northwall Road (below).


1-way cycle track transitions. Also note the footways
and the carriageway is the same colour.

So far, so logical. The concept of using a 2-way track bent out from a main road with connections to a pair of 1-way cycle tracks into the side road is good as it protects people within the entire junction.


But then we start noticing the odd details. The 1-way cycle tracks don't have curved transitions into the 2-way cycle track. The kerbs literally meet at 90° which means it is pretty much impossible to stay in the cycle track for some of the turns (above); these would be impossible with many non-standard cycles. The transition from Temple Mills Lane features a sharp bend complete with a steel bollard in the middle of the cycle track (2nd photograph above).

We also notice that everything is at the same level (below). There is no tactile information (a kerb upstand) to help guide those who need it and the footway, cycle tracks and carriageway are all at this one level.


We also have the carriageway and footway surfaced in the same buff surface dressing (see 4th photo above). Apart from the fact that this surfacing always ends up with tiny stones coming loose making it a slip risk, it is another feature which is going to make it hard for some people to distinguish space for different modes.


The 2-way cycle track carries on over the carriageway of Northwall Road between "elephant feet" markings. This could mean that in the future the crossing will be signalised or operated as a parallel zebra crossing (with stripes added on the pedestrian side for the latter). I guess this depends on how busy the road will eventually be.


Finally, there are a couple of little rain gardens which is nice to see, although these could have been far more extensive given how much paving there is within the junction and so they don't really fit into the street scene.

So there we have it, a little curiosity which is good in principle, but poor in execution. I have to wonder, that in all the years since the Olympics were first announced, why are layouts still being delivered this way? I'll leave you this week with a quick video of the layout.

Saturday, 11 September 2021

Five Go Mad In Dorset*: Part 3 - Sunny Seaton

OK, Seaton is in Devon, but our recent camping trip was based in Dorset! This week is the third and final part of this mini-series where I pick out the interesting bits of streets and transport stuff from the trip.

Seaton is a pleasant little town on the south coast of Devon which contains a surprising transport oddity. First, the town itself has a nice little pedestrianised core, although it really should be updated to allow cycling given that permit holders with motor vehicles can access it (below).


In common with many old towns and villages, the core layout is completely human scale and walkable with everything in proportion for foot traffic.


This pedestrianised part of the town is another great example of using traffic management to allow those who need access for loading or absolutely necessary parking while keeping the space for people.


For some reason, the benches in the town centre have snakes holding up the slats, maybe a little hint of some local quirkiness?


To the south of the town centre, there's a beach which is somewhere between a faded seaside promenade and new development with the quirky public art marking flood gates in the sea wall (below).


To the east of the town centre, there is more modern development with a couple of large supermarkets and the main town car park. It is here that one must go to for a real surprise - the Seaton Tramway

This transport oddity is actually a double piece of heritage because for the most part, the tramway is a repurposed section branch line of the London & Southwestern Railway which ran between Seaton Junction and Seaton itself as the town became a holiday destination. By the mid 1960s, the branch had closed along with the first piece of it's history.

As the railway closed, Claude Lane negotiated a purchase to establish an electric tramway which opened in 1970 (lots more detail here) with an extension to the town centre coming a few years later. So we have the second piece of heritage, because it is now 50 years old! 


Above is a photograph of the tramway's maintenance depot which is right on the eastern edge of the town next to the River Axe. The extension to the town includes the southern terminus which was rebuilt and enlarged just a couple of years ago (below).


The Tramway is a narrow gauge light railway and it carries all sorts of trams which were purpose built by the company, including modern units from the mid 2000s. In the photograph below (left to right) we have 2006, 2004 and 2007, all three being low floor and wheelchair accessible.


There is even a level crossing on the A3052 Swan Hill Road which is operated by the tram driver;



It's the kind of thing that gets me thinking. If an entrepreneur can build a little tramway like this for tourism (with newer units being wheelchair accessible), are there any lessons we could take away from this to create other tramways for transport?


Could narrow gauge tramways actually be built to different internal space standards to provide very light railways? The stairs to the top of the Seaton Tramway aren't exactly easy for everyone to use, so maybe some multi-car single deck units would be better. Could such tramways even operate autonomously to provide short connections between edge-of-town stations and town centres or tramways through town centres where motor traffic is otherwise banned for those needing a little more help (it's being thought about by Coventry City Council).


The Seaton Tramway is a little piece of quirky tourist folly, but I think there is something here to look more closely at, especially as this narrow gauge could get us into some historic street layouts. As ever, there isn't often anything new in transport.

Saturday, 4 September 2021

Five Go Mad In Dorset: Part 2 - Poole's Pedestrianised Port

One of the best things about spending time mooching about places is the little surprises that one stumbles upon and in the case of Poole, there was an unexpected gem down by the quayside.

We visited Poole just to have a couple of hours wandering around and by happenstance, the route the sat-nav was suggesting to take us to the local multi-storey car park was closed to motor traffic. Rather than taking to social media to claim the world was about to end, we found an alternative parking place nearby and stretched our legs.


Above is the view east along The Quay at the junction with Thames Street with a modal filter a bit further up. You can see a loading bay on the right hand side of the street helping to serve the businesses beyond, although not everyone was playing by the rules.


Above is a closer view of the filter which uses the now familiar planters and and bollard arrangement together with the "road open to people" sign. So far, so wonderful.


The filtering of The Quay has immediately created space for restaurants to add outside seating space with a wide area for walking and cycling (above) which yet again shows that in the right place, the two modes can easily coexist when you take motor traffic out of the equation.


Just north of The Quay is the High Street which is also filtered at Castle Street where I noticed a bit more about the scheme. The filter operates 24/7, but the street is accessible for loading (above) between 10pm and 10am. Personally I'd like to see loading end a little earlier in the morning, but it does mean that the street is available for the peak times that people are shopping and visiting the restaurants and cafes. What is particularly good is the positive sign telling drivers the way they should be going in addition to the restriction.


As you can see in the photograph above, the full width of the street is available for other uses, again with more space for eating and plenty of space for walking (and access by cycle if needed). One thing you'll see is the footway widths are inconsistent and often narrow, so having the carriageway available is far more accessible for all (below).


To complement the scheme, the area is a Restricted Parking Zone (RPZ) which means that only traffic signs are used to provide parking and loading restriction information. Some of the signs are attached to buildings which is an excellent way to reduce the clutter of sign posts and shows thought by the designer. The yellow part of the sign is the replacement for the double yellow lines and the white part is the loading ban. 


This approach is a really good example of how we can balance the needs of people wanting to shop and eat in a narrow street with the needs of businesses actually having to service the same premises. When we prioritise a place for people rather than through traffic, we all of a sudden do have space for people and servicing.


Sadly, this scheme is slightly too good to be true. With thanks to Engineer Like a Girl, it turns out that it was originally installed in the summer of 2020 as an Emergency Active Travel Fund (EATF) scheme which was made permanent in May this year, but with the decision taken for it to be seasonal between 1st April to 31st October. Below is the permanent scheme arrangements reproduced from the council's website.


As you might expect, there were plenty of comments in response to the scheme, but I assume that majority of businesses asking for the scheme to be seasonal swayed the decision (you guessed it - car parking, despite the 500+ space multi-storey car park next door). Still, the summer season scheme is clearly a positive change and I hope the businesses change their views over time. It's still a great little scheme which we should be doing far more of in the UK.

Saturday, 28 August 2021

Five Go Mad In Dorset: Part 1 - EV/AV

Thankfully, we've been able to get away for a break this summer. As had become the family tradition before Covid hit, we went camping, although because of Covid (and a touch of Brexit) it was in the UK - Dorset and East Devon to be precise.

Two days before we were due to load our kit into our aging (2007) Vauxhall Zafira, we suffered an electronics failure which left us stranded for hours just off the A12 in Essex waiting to be recovered. I've been driving since 1997 and this is the third breakdown I have had, which isn't too bad I guess and one of those was a distracted driver wiping me out on a mini-roundabout!


Being picked up at 4am from an isolated bus stop
after hours of waiting wasn't much fun.

For some reason the roads gods weren't on our side that day, despite the car not doing many annual miles and it being kept serviced. Sometimes the cleverer part of the technology simply fails. We were a little stuck, but our local vehicle hire centre sorted us out with a car. As it turned out, we ended up with an "upgrade" on what we had actually booked which meant another interesting bit of transport life experience.


The hire car. With #TheDoodle for scale.

We had ordered a Nissan Qashqai with our variables being cost and boot space - our Zafira can carry our family of five, our large tent, a table, chairs, boxes of food and utensils; and clothes; we have managed nearly three week stints and hundreds of miles across mainland Europe like this in recent years.

As it turned out, we had been given a Vauxhall Grandland X Hybrid 4 (with an automatic gearbox with *8* gears and 4 wheel drive for some reason). My knowledge of makes and models of cars is pretty much stuck in the period before the mid 2000s and to be honest, most cars look similar these days. The first thing to note is this is marketed as a "sports utility vehicle" and compared with the Zafira's carrying capacity, there wasn't very much utility given what we had to ditch in order to fit the tent into the boot!

In terms of "sports", I assume this refers to the insanity of a 146mph top speed and 0-60mph in 6 seconds, the latter because the vehicle is a hybrid with electric drive which adds to the power when one plants one's right foot. Anyway, this isn't a car review as such, but some of the more industry standard features were quite interesting to experience.


The car plugged in for some additional range.

First is the fact it is a plug in hybrid. According to a review I have read, this is more about people using it for daily commutes and short trips using the electric mode which carries one for around 30 miles. This is aimed at people who have somewhere to charge the vehicle at home (and maybe at work). Given that 61% of trips are by car and the average car trip time is 22 minutes (2019), many people using plug in hybrids will barely need to use petrol (in the case of this car, the hybrid range is about 400 miles).

This alone is interesting because so long as people have somewhere to charge (whether plug in hybrid or pure electric), as time goes on, less fuel from the forecourt will be needed and so the whole issue of vehicle emissions duty and fuel duty will lead to a collapse in revenues to the Treasury. This either means road pricing or everyone paying to subsidise driving more than we do today.

The charging experience was also interesting. In Dorset, some council-owned car parks had chargers run by Mer which needed an app to access them with a debit or credit card for the other kind of charging and once we were set up we could use them everywhere. Unfortunately, in some car parks, the chargers were not compatible because like mobile phones, we don't have one type of system. A couple of people on Twitter tried to explain the ins and outs to me, but nominally it's extra faff.


At a service station, this charger had a different plug
system for each parking space.

In Devon, we didn't come across any chargers, but in the motorway services, it was of course a different supplier (Ecotricity) and another app to connect, although apparently this is gradually changing to a tap payment system with the network having been taken over by Gridserve. In the services, there were only four Ecotricity branded charging spots, whereas Tesla were flooding the marking and had installed a dozen (below).


As someone who hadn't needed to work out who does what before, this all does rather feel a bit like the Wild West and already way more complicated than pulling into a petrol station and chugging fossil fuel directly into the tank. At least in the car we had, we carried a charging cable which was stored in a tray in the floor of the boot which is pretty impractical when you are carrying more than a bag of shopping (below). Amusingly, we carried the cable in the passenger foot well on the way home, but the service station charger had a cable attached!


In terms of cost, electrical charging is way cheaper than petrol; even with a very fuel efficient hybrid engine, the public car park charging was less than half the cost per mile than petrol which has to be quite attractive to people in terms of running costs. If you can charge from home, it is of course even cheaper.

Away from the hybrid and charging technology, the car had cruise control, collision avoidance and lane correction technology (which are all pretty standard apparently). In other words, I could set the maximum cruising speed on the motorway and the car would run at that speed. If it detected a vehicle in front (pulling in or slowing down), then the car would also slow down. In fact, the car could bring itself to a complete stop. The lane correction feature basically means that if one drifts too close to a lane line, centre line or edge of carriageway road marking, the car would gently take control and steer back into the centre of the lane.

The cruise control and collision avoidance technology was interesting. Where there were few junctions, letting the car decide these things meant that fuel efficiency was improved as the speed was constantly adjusted for the traffic conditions. At least with this car, you could see what was happening in the left hand circular display with the needle moving between charging (generating electricity through braking or maintaining speed down a hill) and an "eco" range of engine revs (below).


Personally, I thought the car was leaving braking too late, not because it wasn't going to stop in time, but that braking was later than I was taught - I usually brake for me and the person behind who isn't paying attention.

The lane correction technology was a bit disconcerting. When I overtake, I don't always indicate when pulling back in, especially if I am some distance ahead of the vehicle I have overtaken. I also tend to move over gently over some distance and this meant the car did sometimes try to move me to the right when I was drifting back to the left when changing lanes. Perhaps I should have used the indicators more which interrupted the feature! I had to turn it off on some roads because it just became annoying.

These sensors are (I think) at Level 2 of 5 of vehicle autonomy, where the vehicle can deal with multiple functions, but where the driver remains in charge. For someone who learned to drive in a car without power steering and generally owning cars several years behind the current state of the art, I found the experience both easy and disconcerting. At least personally, I am not sure that I will ever be happy with a car taking over the driving task for me. That's not because the technology is untrustworthy per se, but because for many years to come there still will be plenty of humans making decisions in what is a very chaotic and variable-rich environment. In fact, the variable of people outside of vehicles isn't something I want to see removed!

Driving in town (and our campsites) at low speeds, the electric mode often kicked in and it was notable that people outside of the car simply didn't hear us, whereas at high speed (say 40mph plus) tyre noise was obvious. Two things that I had experienced as someone outside a vehicle, but interesting to experience from within.


Are modern cars becoming bloated at the
expense of space efficiency and versatility?

Finally, we have to talk about size. My first car was a Mark 4 Ford Escort which was 4.02 metres long, 1.64 metres wide and 1.4 metres high. The Zafira B is 4.5 metres long, 1.8 metres wide and 1.8 metres high. The Grandland was 4.5 metres long by 1.85 metres wide and 1.6 metres high. So, the more modern cars are obviously larger, but the slightly fatter SUV didn't feel more roomy than than the Zafira which is way more versatile with the ability to fold out to 7 seats (albeit with a tiny boot) or carry loads of stuff. On weight, the Escort was 900kg, Zafira 1,445kg and the Grandland a whopping 1,860kg - twice the weight of the Escort! 

I have had a love-hate relationship with cars over the years, although the hate side of things is probably more around the act of driving where there are lots of other people also driving. Having grown up in suburbia, owning a car was (and I guess still is) seen as aspirational and certainly this is something that car manufacturers have latched onto (amongst other things). These days, they have become a mere tool to me and this year's interesting trip (aside from being fortunate enough to get away) has reinforced my views on practicality and how on earth are we going to physically charge all of these vehicles. 

Maybe I'm a just being a bit of a Luddite, but casting my mind back, at least my old Escort was cheap and easy to maintain, the Grandland has so much technology onboard, it would be a nightmare to own if something went wrong. Maybe that's the point - many modern cars are so expensive, people have to lease them in some way and so the gadgets are all part of the marketing as manufacturers jostle for customers.

Update 7/9/2021
Well, the Zafira fault was terminal. A local mechanic came and plugged his computer in to find out more and it wasn't good news. A fault in the electronic automatic gearbox was the problem and it's one of those things you can end up chasing and investing lots of cash into.

We've reflected and decided that scrapping it was the best way forward and more than that, we've decided to try being car-free for now given how rarely we were using the car which cost the thick end of £1000 a year just to sit there gathering dust. So with the few hundred pounds we got for scrap, we'll set money aside each month for travel and we'll hopefully get out on some train trips in the coming months.

I've owned a car for the last 25 years, but I'm looking forward to not having the hassle of owning a car for a while at least.


Bye bye!

Saturday, 21 August 2021

Cycle Tracks In Tight Spaces

One of the issues we sometimes come up against is where we have a road with traffic volumes requiring cycle tracks to enable people to cycle, but where there isn't enough space - what are the options?

Of course, there is always enough space if we are willing to be radical, but for lots of reasons, a road may still be needed to move motor traffic and making wider network changes may be way beyond a project scope or funding. It would be better to be working to detailed plans, but we have to be pragmatic. 

Every place is different and so I can only generalise, but there are some basic dimensions for us to consider. For walking, the minimum footway width given in Inclusive Mobility is 2 metres for most situations, although 1.5 metres is considered an acceptable minimum (1 metre could be used over short sections, but that's all). More space is needed where pedestrian flows are higher, such as outside shops.

For cycle tracks, LTN 1/20 (Table 5.2) has 2 metres as the minimum for with-flow (1-way) cycle tracks for fewer than 200 users an hour at peak, with 1.5 metres being the absolute minimum at constraints. Obviously as flows increase, the space needed increases. For 2-way cycle tracks, 3 metres is the minimum with 2 metres at constraints for fewer than 300 users an hour at peak. 

In the case of walking and cycling, we also need to think about effective (usable) width. People take up physical space and so walking by a vertical highway boundary will have people moving out a bit as they cannot walk right at the rear - there is no guidance, but you'll easily lose 200 or 300 mm. 

Cycling loses up to 500mm where there's a vertical element over 600mm high (LTN 1/20 Table 5.3). There's also the case of having a buffer between people cycling and traffic. LTN 1/20 suggests 0.5 metres (no buffer as the absolute minimum) at 30mph (Table 6.1) and 1 metre (0.5 metre absolute minimum) at 40mph. I'm also assuming that a forgiving kerb is used between the footway and the cycle track to absolutely make best use of the space. Having no buffer also allows stepped tracks to be used which again maximises space and allows overtaking.


We're probably looking at something like the layout above. At this point, the footway and cycle track are both 1.8 metres wide.

For driving, Manual for Streets, gives some suggestions (Figure 7.1). Probably something around 5.5 metres is OK for 2-way general traffic, although on busy HGV and bus routes, 6 metres is probably the operational minimum and perhaps 6.5 metres on bends. Certainly in my experience, different bus operators will have different views and even 6.5 metres gets push-back from some operators.

So, what does the minimum look like? Well, if you squeeze things down, you can fit everything into 11.5 metres, but you'll end up with pretty stingy footways and cycle tracks. Active modes are clearly the most space efficient at 6 metres of the width with driving modes taking 5.5 metres. Of course, if we had 6 metres for general traffic, that's 12 metres.


An operational minimum looks a bit better for walking and cycling which each get 2 metres on each side of a street where we have with-flow cycle tracks (8 metres for active modes) and general traffic gets 6 metres - a total of 14 metres.


This starts to show how much space we need for moving motor vehicles. If we wanted to add a car parking bay, then we'd need another 2 metres. maybe 2.5 metres for a loading bay. This immediately throws up a point that on-street car parking is a luxury we cannot afford in terms of space. What I mean by that is if we are retaining a road as a movement corridor (so we need to protect people cycling from general traffic), then we cannot afford the space for parking. Loading can easily be accommodated by having off-peak loading from the carriageway with or without marked bays - drivers will just have to go around loading vehicles.

There is one more iteration of space efficiency and that's going for 2-way cycle tracks. A 2-way cycle track at 3 metres width isn't bad and would give more space for overtaking. They can be easier to thread through signal-controlled junctions, but they are not easily accessible from the side of the street without a cycle track.


We can go tighter where there are constraints, although I'd bet a small sum of money that it would be the walking and cycling infrastructure that gets squeezed by designers because once we squeeze the space for general traffic, we'll lose two-way running. In fact, this sort of squeezing could actually help create more space for active modes. Let's take our stingy 11.5m corridor and make general traffic one-way.


The one-way traffic lane is 3.5 metres now because we need a bit of space within which to manoeuvre between the kerbs. In this situation, loading is not going to be possible as the road would be blocked, but buses could stop as it would only be for a few seconds. We can grab a little bit of buffer space between traffic and the cycle track, although when used by pedestrians as a refuge space, it is still very tight. Alternatively, we could run with-flow cycle tracks in the same width.


The problem with converting a road to one-way will be where there is a bus route. The usual UK approach is to have bus stops in each direction as it's much more legible for users. In theory, in-bound and out-bound services could be on different streets, but it could mean people walking longer distances to/ from stops. It does depend on how the streets are laid out because some people might be walking a longish distance to/ from a pair of stops and splitting in-bound and out-bound services might actually mean one of the pair of stops is much closer to use and we shouldn't dismiss the idea.

As ever, we are getting into network planning issues because there may not be a road network which supports splitting in-bound and out-bound bus services. Where we have this, then the answer to protecting people cycling is perhaps more of a hybrid solution. If we developed a circulation plan, we could have general traffic running into and out of a town or city centre on different roads, while still running 2-way bus services on both. If we only have bus traffic running in one-direction, we could arrange the cross-section to have people cycling sharing with buses.


This is a 12 metre solution, although mixing with buses in one-direction is a compromise and if the bus direction serves multiple routes, it could quickly get to a point where it feels both really uncomfortable to cycle along and bus passengers get held up too much.

The natural progression from these various solution is to change the street to one where most private motor traffic is removed, but that is maybe a future decision, especially where we are still trying to move freight. Bus gates or sections of bus/ cycle streets can be a solution, but again, these could end up being unsatisfactory for cycling and bus passengers. There is also a consideration on where exactly the space needs to be divided up because within a town centre or city centre, we really should be removing all but essential motor traffic - again, not something a single scheme can usually deliver.

The other issue with what I have been showing is they have a lack of space available for landscaping and planting, so we end up with wall to wall hard surface and as cycling is often being retrofitted, there will be situations where the only space available are existing verges with mature trees which immediately creates a situation where we're ripping out trees for cyclists rather than having the correct discussion about how we take away space for (private) motors.

One cross section to think about is a pretty common arrangement of a 7.3 metre wide carriageway with 1.8 metre wide footways to give 10.9 metres to play with.


Again, having general traffic running one-way opens up space to add cycle tracks and at 1.9 metres wide, it's a compromise, but not the end of the world. 

Even if we started with a 6.5 metre wide carriageway, there is just about an option which can be squeezed in if we use mandatory cycle lanes. We could take the general traffic lane down to 3.1 metres and then have a pair of cycle lanes 1.7 metres wide. Coupled with a 20mph speed limit I think this is getting us to the limits of what we can do, remembering that the traffic lane is still going to be reasonably busy.


With these narrow sections, bus stops are always going to be a challenge because there isn't space to float the passenger waiting areas and we are probably left with boarder style arrangements (below) which I realise are not optimal for everyone and it goes back to network decisions and bus frequency.


Pedestrian crossings are probably a little easier as zebra and signalised crossings can include cycle tracks and cycle lanes in the arrangements (below), although there can be issues with cyclists either not obeying the crossing rules or at least behaving in ways that some pedestrians are unhappy with - that's a wider discussion around how we often treat people cycling as little vehicles, rather than remembering that they are more nimble than they would be driving which opens up different considerations.


Alternatively, we can create shared spaces at crossings which maintain continuity for cycling, but which can create conflict and have signals which present a collision risk (below). Conversely, this type of arrangement might be a little easier to use with a non-standard cycle if the road needs to be crossed so access a cycle track going in the other direction or premises.


Junctions have similar considerations around space. Side roads and private accesses need careful though in tight situations as there isn't space for continuous treatments that could use entrance kerbs or similar if we are going for a stepped track rather than with a buffer. If we have a 2 metre cycle track, we could gently narrow it to 1.5 metres to incorporate entrance kerbs, but detailing becomes a bit more complicated. 

The pragmatic solution is probably to either go for a lower general kerb face and then ramp down to accesses over two kerbs with a low upstand or perhaps use splayed kerbs (below) and require people accessing to have to drive even more slowly. Side streets would need to be flush and so maybe using gentle raised tables for general traffic could be a solution or dropped cycle traffic to carriageway level for a very short distance.


30 splay kerbs used at a private access between the
carriageway and cycle track (vertical elsewhere)
and between the cycle track and the footway.

Signalised junctions are probably a little easier in tight situations and the general road space is more generous. Again, though, decisions are required on the space motor traffic actually needs as we often add lanes for capacity on the approaches. Sticking to one traffic lane gives more space to play with in terms of giving people protection and if the road we are looking at is more about traffic flow in and out of a town or city centre, then banning turns can help, especially if we think about the routing of general traffic at a network level.

It's an interesting challenge to see what we can squeeze into a space, but we really need to be able to think bigger in many cases because the thing that often constrains us is having to maintain two-way operation for motor traffic. Once we can see beyond that, we have all the space we need to enable cycling in many cases. Easy for me to write of course, but the solutions are rarely technical, but often political.