First responders help injured people after a van ran into pedestrians on a crowded street on August 17, 2017 in Barcelona. (Photo: Sergi Alcazar/El Nacional)

Last July a van in the French city of Nice killed 86 people. A Berlin truck attack last December claimed the lives of 12 people. London attacks in March and June of this year killed 13 people. Five people died in Stockholm, Sweden, in April. The latest attacks last Thursday in Barcelona and Cambrils, Spain, killed a total of 14.

Since January, 2015, vehicle attacks in Europe have claimed the lives of 127 people, a third of all terrorist attack victims.

The obvious way to prevent such attacks is to erect stout barriers around crowded areas.

In France and Germany, concrete benches and other barriers have been erected around Christmas markets and other crowded places.

In Stockholm, huge concrete blocks have been placed at the entrance of pedestrian areas and granite blocks have been arranged in other areas to force vehicles to reduce their speed.

In Belgium concrete blocks and sand bags have been used to protect open areas where many people gather.

In London bridges have been equipped with barriers to keep vehicles from crossing into pedestrian lanes.

At Buckingham Palace, the time for changing guards has been changed and certain routes have been closed to discourage attacks.

But terrorism experts say it’s almost impossible to predict when a vehicle attack will take places and preventive measures like concrete blocks cant be put everywhere.

After the Barcelona attack, many people criticized the lack of barriers to prevent vehicles from entering Las Ramblas.

In response, Barcelona’s Mayor Ada Colau pointed out that if terrorists couldn’t ram into Las Ramblas, they would just find another place attack.