What kind of road enables passing a streetcar on the left?

In Germany, passing a streetcar on the left is generally permitted when the road is designed to allow for such maneuvers safely. A one-way street provides the necessary conditions for passing other vehicles, including streetcars, on the left side without conflicting with oncoming traffic, as there wouldn't be any.

One-way streets typically have lanes clearly delineated for traffic in a single direction, which allows vehicles to maneuver safely around a stopped streetcar, which may be unloading or loading passengers. This setup helps minimize the risks associated with passing, ensuring that the driver can do so without coming into contact with vehicles traveling toward them.

On two-way streets or other configurations, passing on the left may lead to dangerous encounters with oncoming traffic, making it less safe. Thus, the characteristics of a one-way street make it the appropriate answer regarding the ability to pass streetcars in that scenario.