Six border crossings in San Diego and Imperial counties are upgrading to new technology this summer as part of a plan to improve security and travel times at the nation’s 39 busiest entry points.

The system to be installed at the crossings beginning in August uses RFID, or radio frequency identification, technology that read data imprinted on chips embedded in new security documents, such as passports and other identity cards, issued by the State Department.

By reducing the types of identification documents presented to customs agents, they’ll have a clearer picture of those seeking entry.

The process should be much quicker, said Vince Bond, spokesman for the U.S. Customs and Border Protection.

“This is all moving toward the full implementation of the Western Hemisphere Travel Initiative, which will take effect in June 2009,” Bond said.

In January 2007, CBP implemented the first part of the initiative aimed at the nation’s air and seaports, requiring travelers returning to the United States from Mexico and Canada to carry a passport. As of Jan. 31, CBP required the same of land travelers.

However, there are alternatives to showing a passport.

These include a passport card, a wallet-sized card that costs $20; enrolling in a frequent border-crosser program; an enhanced drivers license (now only offered in Washington state); and a border-crossing card issued to Mexican citizens for short stays.

As of June, travelers entering the country at land border crossings are required to have a passport. Barring that, they may use some government-issued identity card such as a driver’s license along with proof of citizenship, such as a birth certificate.

Customs officials have been working on coming up with a practical technology to improve security processing for several years. The federal government awarded a $62 million contract to Unisys Corp for the work in January.

The new systems are already being installed in Arizona and Washington, and will be rolled out at the busiest ports of entry on the northern and southern borders.

The San Ysidro work is slated to begin Aug. 4-8. The scheduled work for Tecate is Aug. 25-29, and at Otay Mesa Sept. 2-6.

Bond said the work will be done at off-peak hours to minimize disruptions to traffic flow. The first phase involves installation of wiring at the stations, while a later construction phase at the end of this year calls for installing antennas.