In April 2011, Mark wrote a blog post in which he criticized a dangerous junction design suggested by the then new and claimed to be "state of the art" US NACTO design guide. I thought this to be a very good blog post. At that time we would discuss posts before publication and the only thing that I asked to be changed was that the article should include a reference to other types of junction such as the more modern simultaneous green design. That was added before anyone read the post.
|Mark's approximation of Dutch ideas|
applied to a hypothetical US junction
seems to have been misinterpreted as
a design which should be copied.
Many people misinterpreted what Mark had written about and between us we wrote some additional notes which were added to the blog post in order to try to explain.
This confusion continued so Mark wrote a second post to follow the first a month later in an attempt to explain yet more misconceptions. This again included information about more modern solutions, referring to the simultaneous green design and the use of roundabouts instead of traffic lights.
Sadly, the confusion continues
I've re-read both of Mark's blog posts and I still see nothing wrong with what he said. However, there still seems to be a problem. Somehow people keep reading something other than what was written. Rather than seeing Mark's sketch as an approximation of a Dutch junction created with the aim of dissuading NACTO from promoting a dangerous design, people now appear to be using his sketch as a design guide in itself.
|At first sight, this looks remarkably|
similar to Mark's sketch: A design
proposed for Christchurch in New
Zealand, heralded as "safe", but they
have misunderstood. Cyclists are not
supposed to stop at the same stop line
as cars and traffic lights need to be
positioned so that they are visible to
cyclists making the second part of a
right turn. Also, the geometry is wrong.
This would require sharp turns.
In Christchurch, New Zealand, a design which superficially looks similar to Mark's sketch is referred to as "the Dutch intersection", though their design departs in several ways from any real Dutch intersection through which I've cycled.
Is this just a matter of language ? Has this design been picked up so widely for no reason other than that Mark's post referred to this as "Dutch standard junction design" ? This is seemingly a matter of English usage. Junctions which look similar to his sketch are not "standard" in the sense of being "to a standard" but "standard" in the sense of being unexceptional.
Is it because people view the video in isolation from reading the related blog posts so don't ever see the explanations ? Do engineers and planners really try to design infrastructure based on what they've read on blogs, watched on Youtube and looked at through Google Streetview ?
I think some explanation is required.
Junctions like this are neither common nor desirable
In Assen we have no junctions at all which are of this design.
|The closest thing we have to this type of junction in Assen is|
here by the railway station. It was built in the 1980s and
is now planned to be removed in the very near future.
|Part of the plan for the new railway|
station area. The through road is going
underground. Cyclists will not longer be
faced with delays due to traffic lights
I have to cycle quite a long way to find a junction which is really similar to Mark's sketch. About 40 km South of here in Hoogeveen there are some older junctions which have not yet been reworked. One of them is known to me because it is one of two slightly inconvenient points for me, where I am slowed and delayed on a route which I have cycled fairly frequently to visit a friend who lives 100 km south from here.
Older designs simply are not so good as newer designs and they should be where inspiration for other nations comes from. If you are inspired by the Netherlands, take your inspiration from the good stuff.
There is no "Dutch Standard Junction Design"
There is not really such a thing as a standard Dutch junction. In fact, every junction is designed to fit a particular space and is designed with the needs of the traffic in that space. Another blog post shows every traffic light in Assen so you can see the great variety of designs used. In the 1980s it may be been acceptable to expect cyclists to make slow two stage turns but that is a last resort measure now.
The best junction for cyclists at any particular location is whatever can keep cyclists safe while not causing slowing, deviation from a straight line or stopping. In practice, this is achieved in Assen by unravelling routes for drivers from those used by cyclists so that cyclists do not have to interact with traffic lights installed to manage motor vehicles. Where cyclists do have to use the same junctions as drivers, they are often provided with simultaneous green traffic light designs (the safest and most convenient option) or roundabouts.
Junctions between large roads in the Netherlands often don't need to cater for cyclists at all. These include traffic light junctions where cyclists have another route and "turbo roundabouts" which provide convenience for drivers. This special type of roundabout is entirely designed around driving and cyclists have other routes.
The most common junction design in the Netherlands is almost nothing at all
|A better contender for the term "Standard|
Dutch Junction" is something like this.
Much more common than any traffic
light junction, this is in a residential
area, has a 30 km/h speed limit, raised
table, small corner radii, and most
importantly it's not a through route for
Not one option, but many
Where cyclists and motorists do have to use the same junctions, there are many options, not just one. Roundabouts with separate infrastucture for cyclists are very commonly used, for instance.
We demonstrate a wide range of solutions on our cycling infrastructure study tours.
A few days after I published this post, a new website authored by Nick Falbo appeared which promotes a variation on the same design of junction as Mark described three years ago. The main feature of the website at this time is this very well made video which describes Nick's interpretation of a Dutch traffic light junction design:
Not only does this video show a junction design, it also includes car parking in the right place relative to cycle-paths.
It's late as I type this. I've just watched the new video and these are my first impressions. While watching the video, I kept expecting the author to trip up at some point or another, but he does seem to have almost everything covered. Overall, I'm impressed. The video necessarily covers much of the same ground as did Mark's video and I'm very pleased to see that Nick acknowledges that debt. I'm also quite pleased to see that he acknowledges influence from this blog and other sources.
The incorporation of simultaneous green into this junction is not quite right from a Dutch point of view because the geometry of real simultaneous green traffic light junctions is different to this junction. The "corner refuge" will get in the way of the most efficient use of the junction where diagonals are allowed. However, in my view this wouldn't stop the junction being able to work at all in that way and of course we do have to proceed in steps. If the US can start to install civilized junctions based on this design then we will perhaps see variations including more Dutch style simultaneous green in future.
Apart from the 6 m (car length) setback for where cyclists cross the street (itself an important detail), there are no dimensions on the video nor in the accompanying text. This brings me to my concerns:
The devil is very often in the details of implementation. If dimensions are adequate, traffic light timings are adequate, if cyclists have separate traffic lights and motorists can be prevented from making right turns on red (which I know many US motorists expect to be able to do) then I think the design will work well. However, that's quite a list of details. Quite a list of things which could be got wrong if the junction can't be built to the standard that it needs to be built to. I hope that Nick can prevent that from happening.
There is also the not so small matter that this design represents an Americanized version of just one of the many tools used by Dutch planners. This design of junction is only used at a minority of intersections in many Dutch towns. It is certainly an advance for the USA if this type of junction can be built, but please also look to the other interventions taken in the Netherlands but it should not be over-applied. Most of the places where we could have a junction like this in Assen, for instance, are now places without traffic lights at all. Understandably, it may take a little time for those other ideas also to be imported to the USA.
For cyclists, well designed Simultaneous Green junctions are more convenient than every having to make a two stage turn. Roundabouts are also more convenient. However, it's most convenient of all to have no traffic lights or other major junctions which need to be negotiated when cycling.
It's the "second revolution". i.e. getting rid of through traffic in cities and therefore also being able to get rid of the traffic lights and wide roads required to control motorized traffic which has done much to civilize Dutch city centres. This is more of philosophical approach than merely moving concrete, and it's perhaps too much of a leap to make immediately. But this where the big prize is.
Few Dutch people would now vote for a return to what streets looked like in the 1970s.
Another possible pitfall
John Pelletier pointed out another possible pitfall in email: "One thing that I noted he missed and mentioned in the comments is the issue of drivers not stopping at the stop line and blocking either the bike lane and/or ped crossing. In the US the standard is to put traffic lights at the opposite side of an intersection, I am sure this contributes quite a bit to folks not stopping at the stop bar. I notice in many instances the Dutch bring the traffic lights close to the stop bar so that going past the bar means you have no idea if the light is red or green, this confusion forces folks to more likely stop behind the bar".
In the Netherlands, the traffic lights for cars are always just beyond the stop line, not on the opposite side of the road. If drivers pass the stop line then they can't see whether the light is green or red.
Has Alta altered ?
On of the reasons why I am enthusiastic about this video is that Nick works for Alta Planning and Design. I've criticised this company in the past because they were involved in design standards and plans which I consider to be inadequate (e.g. Ontario and Los Angeles). Alta were also involved in work for NACTO which prompted Mark's video and blog post to which this is a reply.
Nick's video criticizes older, more dangerous intersection designs (e.g. two stage turns and merging right turning cars with cyclists) which Alta appears to have supported in the past. These same designs as were also criticized by Mark and myself amongst others. If Nick is the new face of Alta, and this type of design is the sort of thing that we can expect the company to advocate in the future then that's a very good thing. Alta would appear to have altered its recommendations in the light of what has been learnt. I hope to find that Alta will from now on pursue this better design and not merely advocate it alongside the inferior designs.
This could be a very good first step for America... but you do eventually also need to do the other things.
Update 21 Feb 2014
NACTO appear to have adopted Nick Falbo's design. I asked NACTO to let me know whether the new design will replace existing, less safe and convenient, junction designs in their standard or whether it will appear beside these inferior ideas.
While it is an advance for NACTO to adopt this design, there is a risk that this design could well end up being the best option alongside a range of inferior options in the toolbox available to American planners.
In the Netherlands, junctions like this are an average option offered alongside several superior options in the Dutch toolbox.
My concerns about this type of junction being over applied are still valid.
Is this for countries outside North America ?
There is no reason for countries outside North America to seek to emulate the NACTO guidance. With the adoption of this design, NACTO's best solution for cyclists is a copy of an average solution in the Netherlands. Come directly to the source.
Mark criticized just one feature of the NACTO design guidelines. Read my longer critique of Ontario's design guide, which shares many similarities as well as authorship with the NACTO guidelines.