PHOENIX — A woman driving with her infant son in her car crashed through a gate at Phoenix Sky Harbor International Airport and drove on the runway in the latest in a series of similar mishaps across the country that have raised questions whether the nation's airports are truly secure.

The woman rammed the partially open airport gate around 10 p.m. Thursday and started crossing the runway, police spokesman Sgt. Trent Crump said. Officers forced the car to stop after a few minutes and detained the driver.

KoKo Nicole Anderson, 21, from nearby Mesa, was booked into jail on aggravated DUI and criminal damage charges. Police suspect she had taken an unknown drug and don't believe Anderson was impaired from alcohol. A drug-recognition expert was called to the scene shortly after Anderson's arrest.

The child — a 2-month-old boy — was in a car seat. He wasn't hurt and has been turned over to relatives. Crump said Anderson was so impaired she didn't even know her son was in the car.

"We don't believe her intent was to harm here," Crump said. "We believe it's impairment and poor decision making."

Such incidents are troublesome because a vehicle that crashed into a jetliner landing or taking off could cause a catastrophe, whether it was an intoxicated driver behind the wheel or a terrorist, said Jeff Price, an aviation professor at the Metropolitan State University of Denver and former assistant security director at Denver International Airport.

Airports in general need to think about adding barriers that automatically pop up if an unauthorized vehicle enters a gate as part of an overall upgrade of perimeter security that also includes better detection systems, he said. He noted that Sky Harbor meets federal security standards.

The incident was the latest involving vehicles crashing through the Phoenix airport's gates or fences and getting onto its runways. Sky Harbor spent $10 million to upgrade its perimeter security and access gates after a man being chased by police in 2005 crashed a stolen pickup through a gate and drove onto the runways, passing several jets on a taxiway.

In 2003, two teens in a stolen car crashed through a perimeter fence and drove onto the airfield. Both incidents caused brief closure of aircraft operations.

Anderson had smashed her Saturn sedan into another gate at a nearby parking lot just minutes before, then continued driving and ended up on an airfield access road, police and Sky Harbor officials said at a press conference on Friday.

Sky Harbor spokeswoman Deborah Ostreicher said an airport operations worker was testing the gate as it was closing when the small sedan crashed through. The worker promptly notified police and the control tower, which ordered a halt to air traffic operations.

As the car made it onto a runway, Anderson lost control, then took off again, Crump said.

A police probable cause statement filed in support of the criminal charges said she then hit a portable toilet and kept driving until an officer rammed her car and caused it to spin car around and crash into a fence.

She did not get out of the car after it stopped, and police found her with a pacifier in her month. All she told officers was that she wanted her flip-flop shoe.

Ostreicher said no aircraft were nearby at the time and no passengers were in immediate danger. Airport operations were stopped for about 15 minutes.

The airport's operators are satisfied with its fence security and that Sky Harbor exceeds federal security standards, Ostreicher said. She said the airport has no plans at this point to beef up fence security, but will work with federal authorities to see if there are other things the Phoenix airport could be doing.

"The important thing to know here is that what was supposed to happen happened," Ostreicher said, noting that once Anderson drove into the secure area, the person testing the gate alerted others and officers arrested her promptly.

Ostreicher conceded it's possible that Anderson could have reached a plane, but also noted that there was no aircraft leaving or departing the area at the time.

Similar examples have occurred at airports around the country.

A man crashed his SUV through a locked gate at Philadelphia International Airport on March 1 and drove down a runway at speeds of more than 100 mph as a plane was fast approaching him from behind. The incident caused a major disruption, forcing air traffic controllers to put dozens of flights into holding patterns and delaying the departures of dozens more. He was sentenced to 16 months in prison.

In Grand Junction, Colo., a driver smashed through a fence while under the influence of alcohol in 2008 before getting stuck atop electrical equipment. And in September, an apparently mentally unstable woman drove through a fence onto the West Oahu Kalaeloa Airport in Hawaii and asked to see the airplanes. After she was denied, she drove toward a taxing Air Force C-17 transport, but was stopped.

Earlier this year, a man swam ashore at New York's Kennedy Airport after his personal watercraft ran out of gas. He climbed a security fence and made his way onto the airport. Officials immediately beefed up security after the Aug. 13 incident, which did not trigger an intrusion detection system.

Most airports don't have intrusion systems like the one at JFK, but they should be added, said Price.

Beefing up airport gates by adding pop-up barriers would also address vulnerability like that exposed at Sky Harbor Thursday night.

Normal practice for airport workers is to allow the gate to close once they've driven though so another car can't follow it onto the airfield, Price said. But as Thursday night's incident shows, that's not always possible.

Military bases often use pop-up barriers, and Los Angeles International Airport had added some, Price said.

"What we're trying to do is keep somebody from intentionally coming onto the field and driving into a plane, whether that's because they were drunk and accidentally hit the plane or they intentionally wanted to try and hit the aircraft," Price said.

"Frankly, you don't need to fill a car with explosives and drive it into a plane on the airfield. All you have to do is manage to get on the field and hit the plane while it's on takeoff or landing and you're going to have a catastrophe."

Associated Press researcher Jennifer Farrar in New York contributed to this report.