Exploring traffic lights with location data from cyclists’ phones
In 2006, Amsterdammers voted Frederiksplein the location with the most irritating traffic light. Now, ten years later, data from the Fietstelweek (Bicycle Counting Week) offer a unique opportunity to map how much time cyclists lose at traffic lights. During Fietstelweek, over 40,000 Dutch cyclists have shared their location data using a smartphone app. Some of the findings are summarised on the map above, which shows quite a few red dots - locations where cyclists lose on average 30 seconds or more.
Some of those bottlenecks also featured in the 2006 top-ten of irritating traffic lights, including the ‘winner’ of the time, the Frederiksplein. And many red dots are on the Plusnet Fiets, a network of essential cycling routes where the municipality would prefer an average delay of at most 20 or 30 seconds.
The data only allows for a general exploration of cycling bottlenecks. In order to understand more precisely what’s going on, one would have to analyse each crossing separately. At a few locations, average delays of over two minutes have been observed - perhaps traffic lights are not the sole explanation of those delays.
The data from the Fietstelweek were collected in September. The situation may well have changed since at some locations. A good example is the Muntplein, where cycling is pretty smooth now - thanks to Alderman Litjens who banned most cars and removed traffic lights. A change that occured before the Fietstelweek is the removal of traffic lights at the Alexanderplein. And it shows: all dots are green there.
Cyclists’ organisation Fietsersbond wants traffic lights adjusted to create shorter waiting times for cyslists. Research has shown this to be a measure that is very effective and relatively easy and cheap to implement. But it’s not just about technical improvements; future policies should make ‘radical choices’ in favour of bicycle and pedestrian traffic, in order to prevent the city coming to a standstill due to congestion.
This seemed like a good occasion to organise a follow-up poll on traffic lights. Click here to vote for Amsterdam’s most irritating traffic light - 2016 edition.
The Fietstelweek is an initiative of cyclists’ organisation Fietsersbond and a number of consultancies and research organisations. Between 19 and 25 September 2016, over 40,000 cyclists have used an app to share their location data. The Fietstelweek data has been made available (thanks!) on condition that derived products are also made available as open data. The processed data of my analysis is here and the code for processing the data here and here.
The Fietstelweek data is available in the form of routes, links (intensity and speed) and nodes (delays). The nodes data contains a variable tijd (time). This is the delay along the trajectory between 50m before and 50m after the node, relative to the time the cyclist would normally take to cycle 100m (thanks Dirk Bussche of NHTV Breda university of Applied Sciences for details on how the data was processed).
The dataset contains over 750,000 nodes. I filtered them in three steps: only nodes that are within a square around Amsterdam; only nodes near traffic lights and only nodes with at least 50 observations. This resulted in 1,845 nodes with almost 400,000 observations. For details see the scripts.
Data on traffic lights is from the municipality.
In a new policy to be decided early 2017, the municipality indicates that the average waiting time for cyclists, measured at the busiest hour, should not exceed 45 seconds. At the Plusnet Fiets, it is further deemed desirable that the maximum delay doesn’t exceed 20 seconds at busy crossings an 30 seconds elsewhere. Delay times include the effect of slowing down and accelerating. ↩