"There's a giant explosion of interest," Stark said. "People sitting in a traffic jam see the bikes filing past and it makes them think twice about sitting in their cars."
There are 68 million bikes in Germany, a country with a population of 82 million. The total has risen by 2 million in three years. Bike sales have also remained strong in the past year, defying the economic crisis.
Cycling is a big industry with annual turnover of 1.7 billion euros ($2.40 billion) for cycles and a total of 3.5 billion euros for equipment. It employs about 9,000 people.
In Berlin's government quarter, hundreds of journalists, lobbyists, politicians and businessmen can be seen on bicycles at any time of the day between April and October. There are a growing number of die-hards who ride through mild winters.
Some prominent Germans take advantage of Berlin's bicycle-friendly wide avenues and bike lanes to pedal to work.
Deputy Finance Minister Joerg Asmussen and Martin Wansleben, managing director of the Chambers of Industry and Commerce, are regular bike commuters.
"We're always looking for ways to improve the infrastructure for cyclists to make it even a more attractive alternative," Berlin's Economy Senator Harald Wolf said in an interview.
The city spends 3 million euros ($4.24 million) a year improving 600 km of cycle paths and lanes.
"There are several big advantages of getting around by bike in a city like Berlin," Wolf told Reuters. "First of all, it's a cheap way to travel, and secondly it's positive for the environment because there's no CO2 emissions.
"On top of that it's healthy and in cities like Berlin that have so much traffic the average speed falls so far that you're almost as fast on a bike as you would be in a car."
Rolf Dieter Peschel is another happy cycle commuter. He sold his car and bought a bike two years ago. The 48-year-old, who now rides about 6,000 km per year, reckons it has saved him about 3,000 euros each year.
"I feel a lot fitter than before," said Peschel, who works as an ambulance medical assistant and commutes 17 km each way to work. "I look forward to my bike ride home all day. It's really amazing how much money you can save without a car."
Bettina Krause, 40, paused near the end of her 30-minute, 10-km journey to work at the Technical University at a bike lane traffic light, where 50 cyclists waited for a green light.
"I'd rather take my bike than squeeze into a crowded train," she said. "The thing I like about biking to work is that you can integrate a workout right into your day. I can't stand getting into the train any more."Thomas Geithner, a 32-year-old IT worker, said he left his car at home most of the time because the bike was faster.
"It's only about four km each way so I'd end up spending more time looking for a place to park than it takes to bike," he said. "There's just too much stress with the car. I'm here on the bike in a few minutes and in a good mood all day."