Nice. Berlin. London. And now, Barcelona.

Deadly attacks involving rented vehicles driven into crowds of pedestrians have been carried out in several cities with a horrific degree of similarity.

In fact, the brutal method is promoted by ISIS online. It has become common enough that governments across the world have started adding protection in public locations in hopes of preventing future terrorist attacks.

Bollards, a type of metal post, are designed to block fast-moving vehicles from veering off streets and reaching civilians on foot. The barriers have been installed in Ottawa at Parliament Hill, around the prime minister鈥檚 office and in New York City鈥檚 Times Square.

 

CTV public safety analyst Chris Lewis says bollards aren鈥檛 a cheap solution, and 鈥渢axpayers are going to pay for it.鈥

鈥淏ut it's going to save lives," Lewis said.

Other cities have taken a subtler design approach. In Australia, decorative boxes have been installed alongside a busy thoroughfare. London鈥檚 Emirates Stadium, home to the Arsenal Football Club, is dotted with obstacles including cannons and concrete signs to prevent a car from reaching crowds.

On Wall Street, the pedestrian mall is protected by reflective metal blocks that aim for both style and function.

Ed Turzanaski, co-chairman of the Foreign Policy Research Institute鈥檚 Center for the Study of Terrorism, says bolstering security infrastructure is important now more than ever.

鈥淵ou have an open plaza where a vehicle can come flying in. There ought to be physical barriers to that vehicle,鈥 Turzanaski told 麻豆影视 on Thursday.

Precautions are an important step. But Stephanie Carvin, a Carleton University assistant professor of international affairs, says intelligence remains the most effective way to detect and prevent attacks.

"What national security agencies need to do is have good intelligence on the ground. It's really the only way to stop these kind of lone actor attacks," she said.

With a report from CTV鈥檚 Glen McGregor