So how does Dutch road design work? I bought the CROW manual and to be honest it is not that easy to follow if you are new to the surprisingly complex science of road engineering. A few people have tried to make a summery and done not a bad job and so please do follow the links for more information and better explanation.
If you want to create an environment where normal people consider cycling here is my over simplification of how to do it:
1. Make a Network.
You need a route from A to B and it should be direct and pleasant to cycle along. Bits of good infrastructure are nice but if they lead to unpleasant sections then the route is unpleasant. 100% consistent coverage turns cycling into a daily habit rather than a occasional option.
There are methods and models for charting population centres (housing) and destinations (schools, offices etc.. ) that can me mapped to desire lines and routes. This is complex but if done properly can lead to the most efficient allocation for resources and allow you to concentrate on the important routes first.
There are 3 types of safety.
- Social safety: Will I be attacked on my bike?
- Subjective safety: Do I feel safe on my bike?
- Objective safety: How many km do I have to cycle before I am injured?
Subjective safety is how people judge how safe they are and that has little to do with Objective safety: For Subjective safety you need to minimise to occurrence of situations where mistakes can be made and make the environment pleasant.
It is important to recognise that people make mistakes and bad judgements: For Objective safety you need to minimise the effect of mistakes. Cars crashing into cars or bikes crashing into bikes normally results in people walking away from the accident. However cars crashing into pedestrians or bikes is only a fair fight at low (<30kmph) speed.
3. You have to define the role and function of each road.
Each road has to have a function. Either it is for transporting traffic through it or it is a destination. If it is a bit of both then it is hard to design for bicycle traffic.
A destinations should be a pleasant place to be and have low motor traffic. Think of the road you live in. Do you want commuters to race down it trying to get to work on time or taking a short cut down a back street (Rat Running)?
A through road is for getting as much traffic through as possible. They are not pleasant places to be at all but are required for mobility.
Of course this is an over simplification and there are a few types and levels of traffic intensity. This is explained here and can be grouped in the 3 main types:
- Access roads (aka estate access roads) - streets that provide access to destinations, non-through routes to motor traffic.
- Distributor roads (aka district access roads) - streets that provide access to estate access roads, non-direct through routes.
- Through roads - roads that link distributor roads together and act as main routes for motor traffic.
4. Choose the right solution.
On Access Roads where traffic speed is less than 30kmph and there is no through traffic bicycles and motorised traffic can mix together and be largely unregulated without traffic lights or strict rights of way. In these environments there should be no need for cycle infrastructure or even road markings. However the road must look and feel like a place where it would be socially and physically unacceptable to drive fast. The road also needs to be a dead end so that there is no through traffic and have traffic calming devices and techniques applied.
A Through Road is not a place that is pleasant to cycle. Separation through alternative routes or separate cycle paths is essential.
Distributor Roads require complex solutions and are difficult to get right.
5. Get the Junctions right.
Where roads meet you have a combination of different types and traffic densities and so need a variety of solutions for the number of possibilities. This results in designs for:
Junctions with Rights of way
Traffic Controlled Junctions
6. Be consistent.
Behaviour should be predictable and familiar if good "what are they going to do next" decisions are to be made. Therefore roads need to be familiar and consistent.
7. Maintain and improve.
As new housing / offices etc.. are built population and routes evolve. This is a continuous process that never ends. The computer model needs updated with new population density and facility data very 5 years to improve and complement urban planning.
Point 2,3,4, 5 and 6 are my attempt to describe what the Dutch Call: Sustainable Safety.