Who use the Dafne Schippers bicycle bridge

If all goes well, the Dafne Schippers bicycle bridge in Utrecht should reopen on Monday, after a short closure for maintenance. I have a special affinity with this bridge: it opened on the day I started working in Leidsche Rijn, west of the Amsterdam-Rhine Canal, and it’s part of my favourite cycle route to work.

Who else use this bridge? With the usual caveats, data of the Fietstelweek can provide some insights. The charts below show, for each direction of traffic, at what time cyclists use the bridges across the canal.

There’s a morning peak in cyclists crossing the canal from Leidsche Rijn (west) to the city centre (east), and a peak in cyclists going the opposite direction around 5 pm. This suggests that the bridges are popular among commuters from Leidsche Rijn. That doesn’t really come as a surprise: if you cycle to Leidsche Rijn during the morning rush hour, you ride past huge numbers of cyclists going in the opposite direction.

The map below shows the routes of cyclists using the bridges. From top to bottom: Hogeweidebrug (or Yellow Bridge), Dafne Schippers bridge and De Meern bridge.

It appears that many cyclists use the bridges to go to the area around Central Station. Users of the De Meern and Dafne Schippers bridges tend to use nice routes that converge along the Leidseweg. Users of the Yellow Bridge use the not-so-nice route along Vleutenseweg, or the slightly better route along the railway track.

Research has shown that cyclists don’t always prefer the shortest route to their destination; the quality of the cycle tracks also plays a role.

Yet the map suggests that many cyclists opt for the shortest route, even if a nicer alternative is available. For example, few cyclists from the northern part of Leidsche Rijn seem to use the Dafne Schippersbrug, or the route along Keulsekade (the latter avoids long waits at traffic lights).

See also this analysis by DUIC, which shows that the bridge is not only popular among cyclists, but also among runners, which is fitting given the name of the bridge.

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Logos of rider unions

A nice map circulating on Twitter (here, here and here, via) shows where food delivery workers are organising. Many of their logos proudly feature bicycle parts. The Finland-based Foodora campaign is the exception; their logo appears to have been inspired by Alexander Rodchenko’s КНИГИ poster. Also note the elegant logo of Collectif des coursier-e-s / KoersKollectief.

While their fight is about the future of work, some of these groups are independent of established trade unions - and some don’t consider themselves trade unions in the first place. Riders have used wildcat strikes and other forms of direct action, as well as initiatives such as crowdfunding a strike fund. With employers like Deliveroo trying to «disrupt» the labour market, it makes sense that their workers don’t play by the rules either, it has been argued.

Unfortunately, I couldn’t find an example of the Swiss fiery backpack logo.

UPDATE - added logos from Scotland and Finland

Which Amsterdam neighbourhoods might qualify for an Airbnb ban

Last week, city council member Sofyan Mbarki (Social-Democrats) proposed a motion to ban holiday rentals in Amsterdam neighbourhoods such as the Haarlemmerbuurt, the Kinkerbuurt and the Wallen. A concentration of holiday rentals results in rising house prices, lower social cohesion, increasing pressure on the housing market and inequality, he argued. The motion has support from a majority of the council.

The city government is inclined to implement the motion, but alderman Laurens Ivens (Socialist Party) wants to study the legal aspects. He considers the neighbourhoods mentioned in the motion good candidates for a ban on holiday rentals, but he doesn’t rule out that other neighbourhoods may be selected.

So what neighbourhoods might qualify? One criterion might be Airbnb density, which is shown on the map below (for caveats see Method below).

Unsurprisingly, neighbourhoods with high Airbnb density overlap with areas where residents complain about holiday rentals: Centrum-West, Centrum-Oost, Westerpark, Oud-West/De Baarsjes and De Pijp/Rivierenbuurt (source).

Airbnb frequently claims that it contributes to tourist dispersion because many hosts are located outside the city centre. However, the map suggests that Airbnb is in fact heavily concentrated in neighbourhoods such as the Wallen, the Jordaan, the Pijp and the Kinkerbuurt. While some of these neighbourhoods are outside the city centre, the pattern appears to be concentration rather than dispersion.

While these neighbourhoods would be likely candidates for a ban on holiday rentals, Ivens may also want to anticipate future developments. A number of neighbourhoods still have a relatively low Airbnb density, but have seen their density double or even almost triple over the past three years: Transvaalbuurt, Hoofdweg e.o., Van Galenbuurt and Westindische Buurt.

UPDATE - It was rightly pointed out that Airbnb density partly reflects housing density. An alternative measure would be Airbnb relative to addresses or population. However, this would result in high values for some areas with low population density where holiday rentals don’t appear to be perceived as much as a problem as in some of the more densely populated areas.

See also:

  • Is tourist dispersion working? An analysis of Lonely Planet maps
  • Airbnb’s agreement with Amsterdam: some insights from scraped data

Method

Both Murray Cox’s Inside Airbnb and Tom Slee provide data collected by scraping the Airbnb website. While this data has some limitations, it’s probably the best publicly available data source on Airbnb. Since Tom Slee stopped collecting data last year, I used Inside Airbnb data for the current article. A discussion of methodological aspects related to that data is here.

In addition, I used land surface data from Statistics Netherlands (CBS). This data is for 2017.

I calculated an indicator for Airbnb density in the following way:

  • I assigned each listing to a neighbourhood (note that coordinates for listings aren’t 100% accurate as discussed by Cox);
  • For each listing, I calculated an indicator for the number of stays as: reviews per month (an indicator of the number of rentals) * the minimum length of stay (capped at 3 nights following this study) * the number of beds (an indicator for the number of guests, capped at 4 because that’s the maximum number of guests allowed by local regulations);
  • I summed that number for each neighbourhood and divided that by the land surface of the neighbourhood (ha).

Note that the indicator for the number stays will not be equal to the actual number of stays, for a number of reasons:

  • It’s possible that not all beds are occupied;
  • Not all guests write a review (Cox suggests the number of rentals could be twice as high as the number of reviews);
  • People may stay longer than the minimum number of nights;
  • Sometimes more than four people may stay in an Airbnb, despite the fact that that’s not allowed;
  • For some listings, the indicator could not be calculated because of missing data (about 11.4%).

According to Airbnb, the number of stays in Amsterdam is 2.5 million. Based on that number, the actual number of stays would be about 3 times as high as the indicator for the number of stays I calculated. Given the considerations listed above, that’s more or less what one would expect.

Python script here.

After the voter revolt: Collaboration in the Amsterdam city council

The 21 March city council election saw a bit of a voter revolt. Four new parties got elected onto the city council, thanks primarily to voters in the less affluent, peripheral parts of the city. The election outcome reflects Amsterdam’s social divide.

As a result, the composition of the city council changed considerably. So how are the established parties and the new parties getting along?

Before trying to answer that question, let’s have a look at collaboration in the previous city council. There was a left-wing majority in the council, but the government was relatively right-leaning. There was an effective opposition, with GroenLinks (Green Party) and PvdA (Social-Democrats) frequently collaborating to file motions and amendmends.

The chart below shows collaboration in the current city council. The city now has a more left-leaning coalition of GroenLinks, D66, PvdA, and SP. The pattern of collaboration has changed considerably.

The chart suggests that there are three clusters in the city council. One contains the coalition parties GroenLinks, D66, PvdA, and SP. The second contains right-wing / conservative parties VVD, CDA, FvD and PvdO. And the third contains DENK, BIJ1 and ChristenUnie. PvdD (Party for the Animals) appears to be a bit of an outsider by this measure.

Opposition

Are opposition parties able to exert influence, despite their divisions? An interesting measure is whether they succeed in getting proposals adopted despite a part of the coalition voting against. So far, this has happened twice.

One case was a motion from Diederik Boomsma (CDA), asking to provide parking permits to people who have a private garage but have turned it into something else. Coalition party GroenLinks voted against, arguing that people who have made the decision to use their garage for other purposes are now turning to the city to solve their parking problem.

The second one was a motion from Sylvana Simons (BIJ1) asking to the local government to support teachers in their fight for fair wages. PvdA voted against, arguing that the alderwoman had already taken a stand.

The motions can be downloaded here, and here’s a Python script to process them.

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Trust instead of algorithms

A number of Dutch cities have contracted a company named Totta data lab to predict which welfare recipients may have committed fraud (the cities were somewhat secretive about this approach, but newspaper NRC wrote about it last spring). Totta has trained algorithms on a considerable amount of personal data: 2 to 3 hundred variables over a period of 25 years.

Such analyses carry the risk that existing biases are reproduced:

Luk [A Totta spokesperson] says that in some municipalities more fraud is found among people who have a partner (e.g., they don’t report income), whereas in others it is people without a partner (failing to report they live together). «But it’s quite possible that only that group has been investigated and we build our algorithms on that.»

Luk says they sometimes add ‘deviant’ citizens to the suspects, apparently in an attempt to look beyond the usual suspects.

Another problem is the lack of transparency regarding how this type of algorithms work. Totta doesn’t disclose its algorithms because it wants to protect its business interests; further, it can be difficult to interpret and explain how algorithms work. As a result, the government is unable to explain what criteria it uses to prepare decisions that affect citizens. Recently, the Dutch Council of State expressed concerns over digital decision-making by the government.

Proponents of algorithms argue that they help to detect more fraud while reducing the burden for innocent citizens. In fact, there may not be such a clear distinction. The organisation of welfare agencies said that alleged welfare frauds are often people who mean no harm, but who get into trouble as a result of complex and ambiguous welfare rules.

Still, Amsterdam city council member Anne Marttin (VVD) finds the approach interesting. She asked if Amsterdam uses algorithms and data mining to detect welfare fraude. The answer is no. This is why:

The city government is aware of the use by other municipalities of algorithms and/or data mining to fight welfare fraud. The city does not use such instruments to deal with or prevent welfare fraud. […]

Our services for welfare recipients are based on trust. Further, the city government attaches great importance to the privacy of citizens and the way in which their data is used by the government, for example to develop algorithms. The city government thinks it’s very important that the use of data mining and algorithms doesn’t have a negative impact on the privacy and the legal protection of citizens.

Source (pdf)

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