This will not be a full point by point critique. I can provide one if Christchurch wants it.
|Christchurch's ideas for a "Dutch|
Junction" prompted me to write this
piece. They appear to have based this
design upon a sketch which was part
of a criticism of someone elses poor
Christchurch's design guide calls this junction a "Dutch Junction". The section about this type of junction starts on page 32 of the document where there are two photos of what the authors think a "Dutch junction" looks like. However, neither of these photos are actually they think they are. The upper photo is actually of a simultaneous green junction while the lower photo doesn't look like the Netherlands.
The Christchurch design misses many key details. The geometry of it is also completely wrong.
Cyclists are shown as stopping at the same stop line as drivers so there is no head start over drivers. That is not according to Dutch practice. In the picture there appear to be no cycle traffic lights. The description only says that separate lights are required "ideally". What's more, they don't seem to have understood how cyclists are protected in the Netherlands from drivers turning left across their path. The Christchurch document merely says that this type of junction "can incorporate advanced cycle starts", which is not the way in which cyclists are usually kept safe in the Netherlands. In the Netherlands current practice would require that drivers turning left do not receive a green light to proceed at the same time as cyclists have a green light to go straight on. There also appears to be no expectation that cyclists will benefit from being able to make a left turn when the traffic lights are red. That's normal in the Netherlands and helps to offset any additional delays that cyclists might have on occasions when they are turning right.
With this design you would also expect to see multiple lanes on road (Mark's sketch, which seemingly inspired this, includes such on one arm). What's more, there's no way for a cyclist who has crossed one arm of Christchurch "Dutch" junction and wants then to turn right to actually see his traffic light as it will be behind him. To end, the angles at the junction are wrong. Cyclists travel through graceful curves, they cannot make on the spot 45 degree turns.
Christchurch's design guide features a mish-mash of different ideas from all across the world with no apparent overall concept of which is the proper way to go. There are some relatively good ideas, though even these are compromised in the way they are presented, but they're given equal billing with types of infrastructure which happily no longer exist here in Assen (advanced stop boxes, cycle-lanes in the middle of the road) and other things which we never had in Assen and would never want to see (sharrows, two stage "hook" turns).
The design guide also offers an interesting insight into how the designers view cycling. For instance, page 16 discusses one type of "major cycleway". This lacks specifics such as how wide a cycle-path should be but they clearly expect cyclists to make slow progress ("approximately 15 km/hr for expected users" of one type of "major cycleway") and they want to micro-manage how cyclists cycle (messages stencilled onto paths "move off path when stopped", "warn when approaching"). This would appear to be a tacit admission that the planned width is rather narrow, such that these low speeds and warnings might be required for safety. Good cycling infrastructure never requires cyclists to travel at an artificially low speed.
Where widths are mentioned, they vary. On page 20 it is said that "a desirable width of 2.4m on
both sides of the road" is required in order that cyclists can pass each other while by page 24 that has reduced to "approximately 1.8m to 2m on both sides of the road"
Christchurch's design guide is not a coherent piece of work but more of a summary of things that the authors have read about, and in some cases misunderstood.
Unfortunately, it appears to lean heavily on photos and opinions swept up from across the internet, some perhaps used without credit and some of them used without the concept being well understood by the authors. That may seem harsh, but I can say for certain that it's true in at least one case:
Cycle Barnes Dance
|Is it not a bit rude to take credit for|
someone else's work ?
More seriously, we have to ask why did they use photos that were swept up off the internet rather than their own. Presumably the answer is that they didn't have any of their own. The probable reason for a lack of photos is that the authors of Christchurch's design guide have never actually seen and used this type of infrastructure. Their take on what a "cycle barnes dance" should look like is as follows:
|Christchurch's take on a simultaneous green junction. They've missed key details of the design. This photo is taken from Christchurch's document. I certainly do not claim credit for it.|
The text accompanying this is also interesting to read. Again, the document refers to separate traffic lights for cyclists being required at such a junction only "ideally", suggesting that you could allow cyclists to cross like this at the same time as drivers were in motion. I'd expect that to cause carnage. It never happens in the Netherlands. There are always separate traffic lights for cyclists at simultaneous green junctions. This is not optional. The document also refers to a possibility of combining the pedestrian and cycle phases, which again does not happen in the Netherlands because this would cause conflict and probably injury.
More bad practice lies below
The further I read through the document, the more examples of lacklustre design glare out at me. On page 38 there's a photo of a really dreadful and actually pointlessly badly designed "cycle bypass" (compare with the same concept done properly). On page 41 there's a relatively decent bus stop bypass design followed by a design which is almost impossibly bad on page 43. By page 57 it's back to discussing how to "encourage slower cycle speeds" (this should never happen) on shared paths on a page which also features a narrow "berm separated" cycle path which has an enormous drain in it.
Christchurch uses the term "hook turn" to refer to what is known elsewhere as a two stage turn. In most parts of the world, the word hook is used in this context to refer to the type of crash that it common to this type of infrastructure.
In general, there's far too much emphasis on on-road cycle-lanes. These are relatively uncommon in the Netherlands and just as in other countries, they're not entirely safe here either. The picture on page 61 especially horrifying. It combines those on-road lanes with several other examples of bad practice, several examples of how cyclists can be put into danger, in one image:
- Cyclists turning left have a potential left hook problem due to there being positioned on the left of left turning motor vehicles.
- Even though there's a separate lane for cyclists turning left, no thought has been given to how cyclists could have been allowed to turn left on red without conflicting with anyone.
- Cyclists going straight on experience added potential for danger due to having to try to stay in the middle of the road cycle lane. Drivers on their right but who want to turn left will turn across this lane.
- Advanced stop lines have never really provided any benefit to cyclists.
- Cyclists turning right are expected to go straight on, then slam on the brakes in front of other cyclists, turn left a bit and wait in the small green box. However, they won't know when the traffic light for their direction has gone green because it's behind them. If there's a separate left turn phase then drivers wanting to turn left who come from behind the cyclists waiting in the box won't be able to get past those cyclists.
- Cyclists need to be able to make efficient journeys so many won't want to make their right turns in this inefficient way. That does not only apply to "fast" cyclists, but to everyone. If a child is late for school, they won't want to use this box either. They will have to cross two lanes of traffic on the approach in order to be in the right turn lane. Drivers will resent this because the cyclist is not using the provided cycle facility.
- Cyclists coming in the opposite direction are forced into a left hook situation with drivers who wish to turn left.
This junction design is a recipe for disaster
I have to also mention that treatment of roundabouts is lacking. On page 64, they're talking about "taking the lane" on roundabouts. That's a very long way from best Dutch practice.
It goes on and on. There are very few gems in there (the bus stop bypass design isn't bad). Very few. Please, Christchurch, if it's not too late, do not adopt these guidelines.
You need coherence in design, not a mixture of ideas picked up from different places and with a wide range of different qualities. Copy from the best, not from everything that you've seen.
Don't guess. Know !
Christchurch could have found out a lot more in advance. For a start, they could have asked us specific questions about how these junctions work. They could have asked about what is actually built and how well it works but also specifics such as measurements of different parts of the junctions, radii. Instead of guessing and writing down those guesses as design guidance, they could have found out in advance and adopted best practice. Christchurch could even have employed us to write about things that we do know about rather than employing someone else to write about what they don't know about.
|Christchurch: Don't just "borrow" my photos|
uncredited, send a party of people on the
study tour to learn about real Dutch cycling
infrastructure. They'll then be able to take
their own photos in the same locations,
having seen with their eyes and used this
infrastructure and hopefully also
understood what they're looking at.
It seems to me to be very strange to start by writing standards and only find out later on what it is that you should have been doing. Surely it would be beneficial for Christchurch to send people to see infrastructure like this first hand before making an expensive and dangerous mistake by copying it incorrectly.
That my photo has been taken without permission and without credit and used in the Christchurch design guide should not in any way be thought to represent my endorsement of their guide. Overall, this is a poor guide to cycle infrastructure design.