Sunday 14 July 2019

CROW Flow

For the first time in a very long time, I have been lucky enough to have had the chance to read lots of guidance and to catch up a little on designing for cycling.

This post was going to be a bit of a review of what is out there, but frankly, after getting more acquainted with the Dutch CROW Design Manual for Cycle Traffic, I thought this was worth concentrating on.


Luckily, the Dutch speak better English than I, so the manual is available in English, although you'll have to save up as it's €135 which is an eye-watering amount to spend. However, as an engineer, it's a cracking read (and I am still working through it) and I shall be rereading it a great deal.

"But, RH, we can't do this in the UK" I hear some of you cry. Well, traffic signals are awkward because the Dutch (and many other countries) have priority for ahead movements with right turners (UK left) having to give priority, although it is often the case that the Dutch don't rely on this because it is still risky - in this video, you'll see a combination of "hold the right (UK left) turn" on the main road and give way turning right on the side road where there isn't space for a turn right lane;



I digress slightly, because the CROW Manual spends lots of time on the principles and the UK can copy most of what's in there (although there are a couple of things we shouldn't copy).

We are constantly reminded that the design approach puts cycling ahead of motor traffic in many cases, but where it cannot, then alternatives can be used to keep the modes apart - I am thinking of grade separation at large roads where surface level crossings would be risky;


There is a clear message to the designer early on;

"Put yourself in the shoes of the cyclist as future user of the design, also taking into account vulnerable groups of cyclists, such as children and the elderly".

The manual is no-nonsense throughout and it sets out to demonstrate that cycling is a very important transport mode for the Dutch and that it should be put at the heart of design. We are also constantly reminded of the 5 principles of cycling design;
  • Cohesion,
  • Directness,
  • Safety,
  • Comfort,
  • Attractiveness,
These 5 principles are constantly reinforced throughout the manual both in how each chapter is structured - the design chapters are set out in such a way that each principle is a sub-heading to be explained and there are regular summaries. In addition, there is a whole section at the end of the manual which provide example layouts and other advice which are referred to throughout the whole document which helps to give understanding and practical visualisation.

The overall chapters are logically set out too;
  • The development of bicycle traffic (essentially Dutch policy),
  • Cycle-friendly design (more general policy and how it fits together at a high level),
  • Basic data (the 5 principles, design speed, design cycle, dynamic considerations),
  • Design of the cycle network (network planning using the 5 principles),
  • Road sections (i.e. 'links' from a UK point of view),
  • Junctions,
  • Implementation, maintenance and furnishings (planting, lighting, signage etc),
  • Evaluation and management (including winter service),
  • Design sheets.
For something so elegantly written, it is very hard to explain to someone who hasn't read it just how easy to read and apply the manual is and so you are going to have to believe me, but perhaps it can be best described as "flowing" in the same way that cycling should be designed for.

One of the (several) points I have picked up is the one that suggests that every time we ask someone cycling to stop, we require them to expend the same energy as cycling 100m. Thinking back to my old commute of 5.6km, I would have to stop at least 8 times; more when giving way at every side road; so I would have to expend another 800m worth of energy or 14% more.

If you are able to afford or borrow a copy of the manual, I thoroughly recommend it and certainly, it needs to be in every design consultant or local authority design team's technical library.

3 comments:

  1. What several things should we not copy?
    What did the Dutch get sort of wrong?

    ReplyDelete
  2. Another „must read“ from CROW is „Road safety manual“.

    ReplyDelete