Lack of interruptions

Why is it important?

The cycle route Arnhem - Nijmegen through Elst also meets Dutch high standards of quality, but because it involves some...

Interruptions - the need for stopping or significantly slowing down - hurt the cycle highway competitiveness in two ways:

• by increasing time required to get from A to B by the time wasted for slowing, stopping, and accelerating again;

• by increasing energy expenditure and unevenness of it; therefore making it more difficult and less comfortable to cycle.

How can it be measured?

Speed profile on cycle highway C95 in Copenhagen before and after introduction of green wave for bicycle.

The main metric of interruptions is the expected number of stops per kilometre.

Typical reasons for stops are the necessity to give way (yield or stop signs) or traffic lights. Traffic lights can offer a different probability of stopping, depending on time split between red and green light, coordination with other traffic lights or advance information for cyclists.

Additionally, it might be useful to quantify time loss itself, e.g. in seconds per kilometre or in seconds per single stop. Although it is not desirable to stop at all, having to wait 10 seconds for a green light is still better than having to wait 100 seconds.

In terms of energy expenditure, e.g. if a comparison is needed between two route variants, one more direct, and the other with more interruptions, each stop can be estimated as using as much energy as cycling additional 75-100 m.

Minimum and recommended values

According to CROW’s Design Manual for Bicycle Traffic, the number of interruptions (e.g. to give way or on traffic lights) on a cycle highway should not exceed 0.4 stops/km and the ambition should be to remove the need for stopping altogether. The easiness of meeting this ambition varies depending on the environment, but in some cases the reality is not far behind. For example, cycling 18 km on the RijnWaalpad cycle highway between Arnhem and Nijmegen train stations, you only have to yield to other traffic twice (0.11 stops/km). 

How is it related to other criteria?

• On most cycle highways, interruptions are closely interlinked with crossing safety. Solutions such as grade separation or raised crossings can both improve safety and reduce the number of interruptions.
• Interruptions affect travel time together with directness and design speed.
• The need to stop in remote areas might also negatively affect social safety.

How to reduce the number of interruptions?

As the main source of interruptions are crossings with motorised traffic, see the measures discussed under safe crossings.