The era of easy air travel is over for the foreseeable future, but a sensible improvement to software in full-body scanners at least represents an important step toward a more tolerable boarding experience at the nation’s airports.

The U.S. Transportation Security Administration will begin installing the software upgrade in the coming weeks in millimeter-wave scanners, including the six operating at the Honolulu Airport. The amended machines now will display a generic outline of a human body, highlighting any anomalies that must be checked further, and will enable both the security officer and the passenger to see the same image.

This is a far more reasonable concession for the traveler to make in the interest of enhanced security than to submit to the existing system, which displays what essentially is a nude image of the passenger’s body. And that scan is visible only to the TSA employee, which adds a layer of distrust to an ordeal that already makes so many people uneasy.

But if the last 10 years of homeland security vigilance have taught Americans anything, it’s that there is no silver bullet that will erase our vulnerability to terrorism.

Even with the advances in full-body-scan technology — a necessary component of the national sec rity plan — the system is less than ideal.

For instance, U.S. Sen. Daniel Akaka has rightly called on TSA to conduct further studies of the health risks associated with the radiation from the scanners. The agency has asserted that the radiation exposure is less than what passengers get while in flight, but that shouldn’t assuage the concerns of the airport employees themselves who are exposed to it for hours at a time.

Further, the scanners should not be necessary for all travelers. It’s encouraging that the TSA recently announced plans to test a prescreening program that would enable passengers who volunteer more personal information about themselves to be vetted so they can get faster screening at airport checkpoints.

Implementing this program would be an auspicious start by the Obama administration, which seeks security screenings based more on assessments of relative risk and on intelligence than what we now must endure in abysmal airport cattle calls.

Enhanced pat-downs are too intrusive when they’re applied indiscriminately to all, particularly children and the elderly.

Finally, the scanners can leave Americans with a false sense of security if too much reliance is placed on technology. After all, there are several examples from recent history of contraband being intercepted, not because they were detected in a scan, but because of a tip.

Intelligence gathering and good basic detective work still need to be central in the national efforts to enhance security.

Nearly a decade after 9/11, the U.S. is still struggling to find the right balance between assuring public safety and maintaining normalcy. The new, less invasive software tips the balance back toward equilibrium only slightly, but it’s welcome all the same.