Nice, Berlin, London and now Stockholm. Over the past year, terrorist attacks using vehicles have become a sad fact of life in Europe. Such attacks are obviously appealing to would-be mass murderers: In most European nations, a truck is far easier to acquire than a firearm or explosives, and sometimes even deadlier. Groups such as the Islamic State and al-Qaeda have taken note, specifically suggesting that a car could be a good weapon to harm civilians.

For authorities, the attacks represent a major problem. Guns and explosives can be banned, but motor vehicles are vital for many city-dwellers. So how do you protect a city from an attack like this? There is one commonly used solution, but it’s far from perfect.

Since the 1990s, many cities in North America and Europe have been installing physical obstacles designed to stop vehicles driving close to the site of a likely terror target. These measures actually predated the rise of the modern vehicle attack — instead, they were largely designed to tackle car bombs, like those used to attack U.S. embassies in East Africa in 1998.

When they were first installed in Washington, they were often crude: huge concrete blocks known as “jersey barriers” placed around monuments and government buildings.

Read the whole story from The Washington Post.

Featured image courtesy of AP