Comparing the expenses for bike infrastructure in different cities

By Christian Enderle


Motivation

I'm currently not happy with the state of the bike infrastructure in the city I currently live in: Augsburg. While waiting for a red light I overheard a conversion, that Munich is doing much more fore bike infrastructure than Augsburg. Other people pointed out that Augsburg has less money than Munich, so obviously they can't spend the same money. That's why I will calculate the expenses for bike infrastructure in different cities, in respect to the available money.

Methods

The cities were subjectively chosen. Augsburg, because I live in it. Munich because of the conversation I overheard. And finally Tübingen and Freiburg because they are known for their good bike infrastructure and I might move there one day.

Numbers

Multiple data will be needed per city:

With this several numbers can be calculated:

Available money per resident

$\text{available money per resident}=\frac{\text{total income of city}}{\text{number of residents}}$

Expenses for bike infrastructure per resident

$\text{expenses for bike infrastructure per resident}=\frac{\text{total expense for bike infrastructure}}{\text{number of residents}}$

Percentage of expenses for bike infrastructure of the total income of the city

$\text{percentage of expenses for bike infrastructure}=\frac{\text{total expenses for bike infrastructure}}{\text{total income of city}}$

Collecting the data

Most of the time the data can be found on the website of the city. This can be done by a simple internet search. The biggest problem is, that sometimes the budgets have different names, or the total bike infrastructure expenses are not listed, but rather single project costs. Then some other sources, like newspaper articles, can be used. The used sources are always linked to clearly show where the data is from.

Data of the cities

The following numbers are all collected for the year 2023.

Augsburg

Munich

Freiburg

Tübingen

Calculating the numbers

All numbers in € are rounded down to 2 decimal places.

Augsburg

$\text{available money per resident}=\frac{263.320.458,85€}{305.981 \ \text{residents}}=860,57 \frac{€}{\text{resident}}$

$\text{expenses for bike infrastructure per resident}=\frac{1.500.000€}{305.981 \ \text{residents}}=4,90 \frac{€}{\text{resident}}$

$\text{percentage of expenses for bike infrastructure}=\frac{1.500.000€}{263.320.458,85€}=0,00569$

Munich

$\text{available money per resident}=\frac{8.581.358.100€}{1.589.026 \ \text{residents}}=5400,38 \frac{€}{\text{resident}}$

$\text{expenses for bike infrastructure per resident}=\frac{25.000.000€}{1.589.026 \ \text{residents}}=15,73 \frac{€}{\text{resident}}$

$\text{percentage of expenses for bike infrastructure}=\frac{25.000.000€}{8.581.358.100€}=0,00291$

Freiburg

$\text{available money per resident}=\frac{682.290.551€}{231.482 \ \text{residents}}=2947,48 \frac{€}{\text{resident}}$

$\text{expenses for bike infrastructure per resident}=\frac{4.349.067€}{231.482 \ \text{residents}}=18,78 \frac{€}{\text{resident}}$

$\text{percentage of expenses for bike infrastructure}=\frac{4.349.067€}{682.290.551€}=0,00637$

Tübingen

$\text{available money per resident}=\frac{336.298.914€}{93.567 \ \text{residents}}=3594,20\frac{€}{\text{resident}}$

$\text{expenses for bike infrastructure per resident}=79 \frac{€}{resident}$

$\text{percentage of expenses for bike infrastructure}=\frac{\text{expenses for bike infrastructure per resident}}{\text{available money per resident}}=\frac{79 \frac{€}{\text{resident}}}{3594,20 \frac{€}{\text{resident}}}=0,02197$

Graphs

To better visualize the numbers I put them in charts:

Expenses for bike infrastructure per resident

Available money per resident

Percentage of expenses for bike infrastructure

Insights

In the first graph we can see that Tübingen spends the most money per resident on bike infrastructure. They spend roughly 4x the amount than Freiburg, 5x than Munich and 16x than Augsburg. If you take available money per resident into account and look at the percentage of expenses for bike infrastructure, Tübingen spends roughly 3.5x the amount than Freiburg, 7.5x than Munich and 4x than Augsburg.

Even though Augsburg spends roughly a third on bike infrastructure per resident, compared to Munich, if you take the available money per resident into account, Augsburg spends roughly 2x the amount of Munich. Furthermore, Augsburg spends roughly the same percentage on bike infrastructure, than Freiburg.

Conclusion

When looking at the money spent on bike infrastructure, it is not as easy, as looking at just the total expenses. The available money also has to be taken into account. The percentage of expenses for bike infrastructure is the more meaningful metric to compare cities.

But the money a city spends on bike infrastructure just tells us how much money a city spends on bike infrastructure. This could mean that the city is actually building good and much bike infrastructure. But they could be also building unnecessary bike infrastructure that is not needed. Or bike infrastructure, but of a bad quality/design. Right now there are no quantitative metrics to compare the quality of bike infrastructure in cities. This could be something to work on in the future.