Helena Bachmann

Special to USA Today

ZURICH – Each night, a beeline of cars forms on the way to a drive-in in this Swiss city’s Strichplatz area, but the customers are not lining up for fast food. Rather, they are waiting for a service of another kind: to spend time with the prostitutes plying their trade in one of Zurich’s famous “sex boxes.”

And it’s all perfectly legal.

In fact, these government-sponsored digs, which look like one-car garages, are celebrating their fifth anniversary Sunday. Last week, city officials announced that the project has been a resounding success.

Prostitution in Zurich is nothing new. For years, hookers conducted their business in the city’s riverfront area, but residents often complained about the noise, traffic jams and other disturbances from carousing clients.

So in 2012, 52 percent of Zurich voters approved a city plan to set aside $2 million of taxpayer’s money to build several drive-in structures in a safe and discreet environment, away from the residential neighborhoods. Another $800,000 was earmarked for annual operation costs, which include security and on-site social services.

A year later, these premises started welcoming dozens of prostitutes and their clients.

To municipal authorities, this arrangement makes a lot of street sense. As the city noted on its website, the premises were intended to “improve the working conditions of sex workers – their health, physical and mental integrity.”

Five years later, these goals “have been achieved,” city spokesperson Nadeen Schuster told USA TODAY.

“The Strichplatz is effective in preventing violence against sex workers and human trafficking,” she added.

And since opening in 2013, several improvements have been made. Originally, the boxes only accommodated customers in vehicles. A year later, the municipality added several wooden structures furnished with plank beds, “responding to concerns that not all customers want to receive services in their car,” the city said.

Motorbikes and bicycles are now also permitted inside “to meet the needs of the population,” authorities noted. Walk-ins are not welcome, though, and are directed to the city’s other officially-sanctioned prostitution area, the Harnigstrasse.

The site is regulated with a Swiss-clock precision: Maps show how to find the area and which way to drive by following arrows painted on the road. The premises are open for business from 7 p.m. to 3 a.m. during the week and until 5 a.m. on weekends.

Once inside, the cost is negotiated with one of the 24 women – mostly from Eastern Europe – who typically work in the Strichplatz. “The price is set by sex workers and their customers. The staff doesn’t interfere in these arrangements,” Schuster said.

After setting the price, the client and sex worker drive to a free box. For privacy reasons, there are no security cameras, but each box is equipped with an alarm button that will summon guards in case of trouble. There have not been any serious incidents so far.

Prostitution has been legal in Switzerland, a nation of about 8.5 million people, since the 1940s and is considered like any other service industry. The Swiss have taken this pragmatic approach to prevent exploitation, sexually transmitted diseases, links with criminal networks and other problems common in countries where sex commerce is banned.

Prostitutes, in turn, are expected to pay taxes and contribute to their Social Security funds. They must also register with public health authorities and undergo regular health checks.

To work in Zurich, prostitutes must fill out a permit request, which is available on the town’s website in several languages, including English. Schuster did not reveal how many are registered but said about 100 work on the streets; most ply their trade with escort services or in brothels.

While the city doesn’t keep track of the numbers of sex box customers, “if there were not enough sex workers or not enough johns, the place wouldn't work. Neither is the case,” Schuster said.

And that’s another measure of the Strichplatz’s success.