Sales of electronic transponders used to pay highway tolls and the number of people using them are up sharply in the Washington region and along the East Coast this year as more people are opting for the technology as a way out of maddening, toll-induced delays.

The jump in the number of users in Virginia, which joined the E-ZPass network in October, has been most pronounced. In October, 118,000 E-ZPass transactions were recorded. By June, that number had jumped to 646,000. Drivers in Virginia are also able to pay tolls electronically with Smart Tags, and during the same period, the number using them rose by nearly 1 million.

Combined, the number of motorists paying electronically has risen by 1.5 million users a month since October, from about 9.5 million to 11 million, and membership has risen from 495,000 to 540,000.

In Maryland, the number of new accounts has risen nearly 18 percent this year compared with last, and sales are up 22 percent during the busy summer travel season. In all, nearly 57,000 people have joined the network this year, nearly one-fifth of the 316,000 total users in the state. State officials said 45 percent of all toll users pay electronically.

The effects of increased E-ZPass usage are significant. For drivers, whipping through tollbooths is a time- and stress-saver, especially on trips through the Northeast, where tolls are ubiquitous. More E-ZPass users also means fewer people lining up to pay tolls the old-fashioned way, lightening delays for other drivers.

For state officials, a large percentage of electronic toll payers means fewer backups to deal with and fewer harmful pollutants emitted while cars idle.

Officials said the rise in users is due to greater familiarity with the technology and the universal desire not to sit in traffic jams.

The results of increased usage are "better operations of roads, drivers are certainly not sitting in traffic as much, and they're not creating more pollution or air quality issues," said Barbara Reese, chief financial officer for the Virginia Department of Transportation.

Public enthusiasm for electronic tolls also bodes well for plans to build more toll roads in the Washington region. Virtually every major road being considered in Virginia and Maryland would have a toll, and the success of the roads would require collection of tolls without slowing traffic.

John Nelson has had his Smart Tag for about a year and doesn't know how he lived without it.

"It was sweet," the Sterling resident said, recalling his first day of paying electronically on the Dulles Toll Road. "I went right through the first toll plaza and right through the main toll plaza."

It doesn't surprise Nelson that more and more people are going electronic.

"For people who live out this way and that regularly take the toll road, I don't understand why they wouldn't get a Smart Tag," he said. "It's better than being stopped at toll plazas waiting for a guy who doesn't have the right change."

E-ZPass and Smart Tag work simply. Users put wallet-size transponders on their windows or windshields that automatically register tolls as the cars pass the tollbooths. Motorists maintain an account that can be linked to a credit or debit card from which tolls are deducted.

In the Washington region, drivers can pay tolls electronically on the Dulles Toll Road, Dulles Greenway and Chesapeake Bay Bridge, as well as at several toll facilities in and around Baltimore. In addition to Virginia and Maryland, E-ZPasses and Smart Tags are accepted in Pennsylvania, Delaware, New Jersey, New York, Massachusetts and West Virginia and newcomers New Hampshire, Maineand Illinois.

The response in New Hampshire, which joined the network in late June, has been overwhelming. Spurred by a deep discount, 228,000 transponders had been sold as of yesterday, said Pamela Walsh, spokeswoman for Gov. John Lynch (D). That number was nearly triple what officials expected and sent them scrambling to get more transponders, Walsh said, adding that 25 percent to 30 percent of tolls are now paid electronically.

States are making changes to accommodate all the new electronic toll users. In Maryland, officials have added numerous signs at tollbooths to direct people to E-ZPass lanes. They have also extended some E-ZPass lanes, including a mile-long extension at the Fort McHenry Tunnel in Baltimore.

Maryland also plans to lengthen the E-ZPass lane at the Bay Bridge this fall, said Cheryl Sparks, a spokeswoman for the Maryland Transportation Authority.

Sparks added that the biggest change in Maryland was made this summer, when the state started selling transponders that can be used immediately. In many places, the only way to sign up is through the mail or Internet, and drivers have to wait to get their transponders in the mail.

Between June 21, when the retail sales began, and Aug. 15, about 5,600 transponders were sold, Sparks said.

Virginia has added express lanes on the Dulles Toll Road so drivers can zip through. Other facilities, including the New Jersey Turnpike, have added similar features, while some states have converted lanes for E-ZPass users only and offer discounts.

Mike Day goes to New Jersey a lot and loves that he doesn't have to sit in long lines at tollbooths. The Arlington resident said the people who haven't converted to the world of electronic transponders and jam-free tolls are missing out.

"I am always shocked by the plethora of cars that do not have E-ZPass," he wrote in an e-mail. "These people sometimes wait 20 minutes to pay a toll that I pay in 2 seconds. They must be too lazy to sign up, and too ignorant to realize how much time they are wasting."