A police officer secures an area near the site of a terror attack in New York on Nov.2017. A pickup truck driver  plowed down a New York bike path, killing eight people in the city’s worst attack since Sept. 11, 2001. Authorities said the killer was associated with the Islamic State group but “radicalized domestically.” (Jewel SAMADJEWEL SAMAD/AFP/Getty Images)

Law enforcement officials in the nation’s capital, which draws millions of visitors each year, are expanding parking restrictions around special events to protect pedestrians and crowds from terror-inspired attacks where vehicles are used as weapons.

The city has been assessing new measures to prevent attacks like those seen in New York and London in the past year, where attackers used trucks and other vehicles to mow down pedestrians.

D.C. police are establishing new parking rules along race and parade routes beginning this month.  The new restrictions will affect the Rock and Roll Marathon on March 10; the annual event draws as many as 25,000 runners and thousands more spectators. Police say the goal is to ensure everyone’s safety.

“With the advent of vehicle attacks that we have seen in the United States and around the world there is a necessity to implement parking restrictions which include removing all vehicles along special event routes, particularly during races and parades,” D.C. police said in a statement.

The changes are likely to be painful for drivers who will be forced to move their vehicles before events in a city with a limited parking inventory.

“We understand that this measure can be inconvenient for some residents and visitors, but we are convinced it is the best practice for protecting citizens from being injured or killed,” D.C. police said.  “The goal is to ensure the safety and security of special event participants, spectators, residents, and visitors in Washington, D.C.”

Parking is already scarce near the monuments, in downtown and in other popular D.C. neighborhoods and the new restrictions are likely to make it even more challenging. Security concerns have prompted parking restrictions in the city before. The Secret Service closed the two-block area of Pennsylvania Avenue in front of the White House to traffic to ward off truck traffic in the mid-1990s due to security scares and in the wake of the 1993 attack on the World Trade Center and the April 1995 Oklahoma City bombing.

“Parking is an endangered species in Washington, D.C. Once you lose a parking space, it is gone forever, never to be replaced, recouped or regained,” said John Townsend, a spokesman for AAA Mid-Atlantic.

The new restrictions, he said, are likely to have an impact on traffic patterns, District residents and tourists.

A rise in the number of attacks where vehicles were used as weapons in recent years has alarmed officials in cities around the U.S. and the world. In June, attackers using a vehicle and knives killed eight people and wounded dozens more on London Bridge. A few weeks later in an incident nearby, a man drove into people leaving mosques after Ramadan services, killing one and injuring 10.

In October a man drove a truck into a crowd of pedestrians and bicyclists on a New York City bike path, killing eight people and injuring a dozen more. Last May, a man driving in New York’s Times Square plowed into a crowd during lunchtime, killing one person and injuring 22. While authorities said the incident was not terrorism, the Islamic State, inspired by the crash, used it to warn that more attacks on the nation’s largest city and popular tourist destinations would follow.

Bollards and security barriers, as well as increased police presence at events, are among some of the strategies that cities are using to guard against such attacks. Seven hundred bollards were planned to be installed along the Las Vegas Strip at a cost of $5 million in what has been called “a matter of life and death” to provide protection. Although there is no specific threat, authorities said that recent terrorist propaganda featuring snapshots of the Las Vegas Strip cannot be overlooked. Each barrier is designed to resist a 15,000-pound, 30-foot vehicle, officials said.

Other cities have increased security, while advocates have called for more investment in barriers to prevent vehicles from entering spaces with heavy pedestrian traffic.

In D.C., officials say they too are studying various measures to prepare for such attacks.  But law enforcement, transportation and other city leaders have declined to discuss specific tactics or any investments in protective measures.

D.C. Council member Charles Allen, who chairs the panel’s public safety committee has said the city must prepare by making “reasonable and smart and strategic investments” in bollards and other tools to protect residents, but it is unreasonable to expect the city will install such measures in every block, or that residents will be walking behind a row of jersey barriers.

“As we think about that, it’s also important that we have a conversation as well about what type of city are we and what types of choices do we want to make,” Allen said during a council oversight hearing last week. Should bollards be on every street?  he asked Christopher Rodriguez, director of the city’s homeland security and emergency management agency.

“The attacks that we are seeing that are happening around the country and around the world, can happen at any time and at any place,” Rodriguez said.  He said there is merit in considering strategic locations across the District where bollards might be needed, but a city plan has to be more comprehensive, understanding that as in the Manchester suicide bombing, bollards alone couldn’t prevent an attack.

“All you need is one individual to walk into a crowd and ignite a device,” he said.