Fort Dix has heavily guarded checkpoints with serpentine courses leading to guardhouses, gates and metal pop-up strips to stop the traffic.

The post has an X-ray machine that sees through trucks, and it checks the military credentials of the top commanders and police officials.

But it allows pizza delivery drivers with temporary vehicle passes to enter after basic local background checks - at least for now.

"I think it's obvious that we must revisit base access procedures," U.S. Rep. James Saxton said today, noting that he was issued a plastic ID card to enter the House of Representatives. "I am currently examining legislation and provisions regarding this matter and may introduce legislation in the near future."

Security at Fort Dix came under scrutiny this week after six men were arrested and accused of hatching a terror plot to kill soldiers at the post. One of the suspects delivered pizzas so that he could scout the base for a possible attack and shared a map of the installation with co-conspirators, federal authorities said.

To head off a potential attack and close the so-called pizza loophole, Saxton (R., N.J.) said, more exhaustive background checks may be needed and plastic identification cards issued to vendors entering the military bases.

Jeff Sagnip, Saxton's spokesman, said military bases across the country depend on services from the surrounding communities, which benefit economically from the presence of the installations.

"A shutdown would hurt the community, but there has to be a better way of screening commercial access," he said. "The policy has to be reexamined."

The security concerns surfaced as McGuire Air Force Base - now part of a joint base with Fort Dix and the Naval Air Engineering Station Lakehurst - was preparing to hold its 2007 Air Expo and Open House on Saturday and Sunday. The annual event is expected to draw a half-million people over the weekend to the four-square-mile Air Force facility.

Military officials said security at the joint base "remains stringent." Soldiers manning the gates have stepped up random vehicle searches and are adhering to a strict 100 percent identification check policy, according to the bases.

Officials also said that current vehicle pass policies would remain in force unless officials saw a need for improvements.

"I'm not saying a change wouldn't be considered," fort spokeswoman Carolee Nesbit said today. "If someone shows there's a better way, we're always open to improvements."

A business owner who requests a pass to conduct business at the fort must undergo a thorough background check, military officials said.

The owner also must provide a list of employees who will enter the post. The base's force protection staff - part of the Department of Defense police - is then notified.

Local background checks are performed on everyone on the list and a temporary pass is issued with the name of the business.

"When the people on the list come to the gate [with the pass], they are checked [by computer] for arrest warrants before they enter the post," said Nesbit. "It's a local check."

One of the terror plot suspects, Serdar Tatar, whose father owns a pizza restaurant near the military installations, was allowed onto the joint base to deliver food to personnel, federal authorities said.

Efforts have been made to increase security at the gates. Saxton helped obtain a $5 million upgrade to the main gate of Fort Dix in 2005, providing concrete barriers that create a serpentine pattern. A $1 million X-ray machine that can see through a truck was also secured.

Other security measures across the joint base are not made public, Nesbit said.

Indeed, Sagnip said the fort shut down roads - once open to the public - after the 2001 terrorist attacks.

"Security has been heightened," he said. "If they attacked the base with AK-47s, they would not have gotten by any of the checkpoints.

"Letting a single pizza delivery man you know come in five or six times in a day is not the same as allowing in a car filled with guys."

Security is a top concern this weekend for McGuire officials as they host the Air Expo and Open House. "We have been planning this for over a year," said Air Force Senior Master Sgt. Patricia Barry. "We want to make sure we don't overlook security issues. . . . We will be a little more vigilant."

Contact staff writer Edward Colimore at 856-779-3833 or ecolimore@phillynews.com. To comment, or to ask a question, go to http://go.philly.com/askcolimore.