As terrorist attacks involving vehicles have become common, cities around the world prepare for the worst-case scenario. Concrete barriers have become the new solution in public spaces. The concept is simple, but are they enough?

CGTN’s John Terrett reports from New York City.

The focus of this story is not people, but barriers designed to protect people from terrorist attacks.

They’ve sprung up all over New York City, most notably in Times Square. But they’re also outside one of the world’s biggest brick-and-mortar shops, the Israeli Consulate on 2nd Avenue, and hardly surprisingly, around Trump Tower on 5th Avenue.

The question remains on whether or not this works. According to Maki Haberfeld of the John Jay College of Criminal Justice, the answer lies somewhere in between.

“They do work but nothing works one hundred percent. Any counter-terrorism tactic is about minimizing and mitigating, not eliminating,” she explained.

There have been a series of high-profile attacks using vehicles where barriers were not installed. In July 2016, a 19-ton cargo truck was used to run over people in the French city of Nice, where they watched fireworks in celebration of Bastille Day. More than eighty people died.

Five months later, there was a similar attack on a holiday market near Berlin.

In May, a driver bearing a grudge drove a red-colored car at high-speed through Times Square. He killed a young woman and injured more than 20 people. Though not deemed terrorism by New York police, it was every bit as violent with the potential for many more deaths.

The feeling is the driver’s options for causing more pain and destruction that day were limited by the number of concrete barriers put up all over Times Square. But some people worry the barriers ruin the good looks of an area, and create an atmosphere of fear that can scare visitors away.

“We are developing here in New York City left and right, and there are various modern buildings, so to put a concrete block with a couple of plants on top of it might look like some modern art, not a security device, but it’s a good solution,” Haberfeld said.

Such barriers are not really a new idea. London had them at the height of the Northern Ireland “troubles” in the 1980s, known as the “Ring of Steel.” Lately barriers have been added to the scenes of vehicle attacks at Westminster and London Bridges.

But while some experts have said these barriers are good, Haberfeld warns the next threat may come not from the streets but the air. This could come in the form of drones that are cheap to buy and easily weaponized.

“Their range in terms of where can you use them, and how easily they can be used, in terms of lack of security is something that we close the airspace, there’s no way of preparing for this … sad and scary but realistic, very realistic,” she said.