Many European cities are promoting bicycles to reduce air pollution and help protect the climate. But as efforts in the former West German capital show, getting people out of cars and onto bikes is not so easy.
Carrying forward its mission to transition to renewable energies - famously called the Energiewende - German cities are taking ever more voluntary initiatives to reduce greenhouse gas emissions across the country.
Bonn, the former capital of West Germany, is among European cities that are banking on bicycles as a means of eco-friendly transport. Promoting bikes is one way Bonn plans to achieve climate protection goals.
The city has vowed to be the most bicycle-friendly metropolis in its state of North Rhine-Westphalia by the year 2020.
Bonn's project of becoming a bicycle capital - or "Fahrradhauptstadt" - is intended to remove 20 percent of carbon dioxide emissions produced by cars on the roads.
However, Bonn's journey to that destination is fraught with difficulty, as the metropolis struggles to balance an influx of cars on the road with setting up safe and convenient cycle infrastructure.
Switching from steering wheel to pedal
Werner Böttcher, a traffic planner from the German Cycling Club (ADFC) in the Bonn/Rhein-Sieg area, put it simply: "We have a traffic problem in Bonn. There are so many cars, so few roads."
Since Bonn's economy is based on office workers and not industry, most pollution comes from commuters.
The challenge is to find a way to get those people in cars to use bicycles and public transport instead, Böttcher added.
Böttcher ruled out construction of new roads as a solution. He believes that best way to promote bikes is by reducing the number of cars on the roads. "That is tricky, because the car lobby is still very strong in Germany," Böttcher pointed out.
In Germany, transport is the second [largest] emission source after power generation.
The Bonn city council imposed the ambitious bicycle capital goal on itself in 2010. In a statement, the former mayor of Bonn, Jürgen Nimptsch, said Bonn launched the project in response to persistent air pollution due to vehicular traffic.
The basic concept is for bicycles to replace cars in the city center over the short and long term.
Specifically, the city's plan includes: establishing more cycle paths in the city; increasing public trust in cycling by assuring that cyclists are safe on the roads; building more bike stations and improving bike parking; and having an integral transport system that accepts bicycles throughout the city.
City officials believe the cycling project will increase quality of life - not just by reducing air pollution, but also by increasing social contact among those in the city, and helping them stay active and healthy.
Being a bicycle city requires good safety standards on the roads. A coordinator in the city's planning, transport and conservation committee, Karin Langer thinks that the people of Bonn do not feel secure when riding bikes.
"I believe people like to use bicycles, but are afraid for their safety," Langer told DW. "They don't feel protected when cycling."
And persuading them that bike-riding is the best option also means demonstrating that it's safe, she thinks.
As one step in winning peoples' trust, the city has planned 175 marked cycle paths by 2020. However, only 25 have been demarcated so far.
If cycle paths are not demarcated, bike riders, pedestrians, and car drivers do not feel safe enough
Staying the course
In terms of reaching their goals within three years, Langer thinks that the city will not be able to overcome challenges to become a "cycling capital" by 2020.
"The due date is near, and I don't think we will be able to accomplish our mission as planned," she said.
But Langer does see the situation improving by then. A modified aim is to see 75 percent of Bonn inhabitants and tourists use eco-friendly transport by the deadline.
As one further step, cyclists are now allowed to ride one next to the other on some streets, which was not possible before.
Trust, not competition
Although it may not be a cycling destination in North Rhine-Westphalia like Münster, Bonn nevertheless plans to continue its efforts - for the benefit of its people.
"It is not about competition [with other cities], it's about winning the trust of our cyclists who are still in cars," Böttcher told DW.
Bonn is listed 18th in a ranking of the most bicycle-friendly cities in Germany, according to a survey conducted by ADFC in 2014. Karlsruhe and Freiburg came first and second, respectively. It is estimated that 82 percent of inhabitants in those towns own a bicycle.
An old cyclist in the city center, who did not want to be named, said that for him, bicycling is personal. "I've been riding a bike since childhood."
"The bicycle is not only a means of transport, but also a strong part of my family culture for many generations."