"U.S. Airports' Curbside Security Questions"

At airports across the country today, tighter security was evident long before travelers reached their terminals. Police at Los Angeles International stepped up random searches of all vehicles. At New York's La Guardia an unattended car drew special attention, reports CBS News' Tony Guida.

But any traveler could tell you this show of extra police at airport perimeters was not the norm. The norm, says one aviation expert, is not reassuring.

"U.S. airports are wide open on the non-secure side before you go through security," said Mike Boyd, an aviation consultant. "I mean, how many airports really do a pass through every couple of hours to look for strange things?"

The attack on Glasgow International Airport was on the minds of at least one family flying today to their holiday vacation out of Newark Airport. The Geffens wondered if concrete barriers, like those erected outside office buildings and landmarks, might make it more secure at curbside.

"Anything you can do to secure with barricades, police — that will help," said Samuel Geffen.

But security experts disagree.

"Security has to be multi-layered," said Jim Bucknam, the senior adviser to former FBI chief Louis Freeh. "Concrete barriers are not enough."

Not when thousands of cabs and cars and limousines and buses arrive hourly outside airport terminals everywhere.

"What we don't want to do after Glasgow is to make it impossible to get to the airport — that way, we give terrorists what they want," said Boyd.

And if what they want, says Bucknam, is to blow up an airport terminal, terrorists can get around any security, especially if they're willing to die doing it.

"They only have to be right once," said Bucknam. "Security forces have to be right every time."

"U.S. Airports' Curbside Security Questions"

U.S. Airports' Curbside Security Questions

Glasgow Airport Attack Worries U.S. Aviation Security Experts, Travelers