Arlington County hopes to have a countywide AM radio station up and running by the end of the year to serve as part of its expanding emergency notification network.

Montgomery County and the Virginia and Maryland departments of transportation have long used low-wattage AM radio signals for traffic and bridge information. But Arlington will be one of the first jurisdictions in the area to install an AM radio station to broadcast countywide, officials said.

The county recently obtained a six-month license from the Federal Communications Commission to test operations on AM 1700 and determine how many transmitters it eventually will need for the project, expected to cost about $100,000, funded by federal homeland security grants. The 10-foot antennas will sit atop utility poles.

County officials said they took the action to create a better way to reach residents in a terrorist attack or other emergency.

On Sept. 11, 2001, Arlington officials were frustrated in their efforts to reach residents as parents rushed to pick their children up from school and several roads were closed. Radio and television stations were inundated with news from New York and the Washington region and didn't have time to air Arlington-specific information.

Arlington School Board Vice Chair Libby Garvey said she vividly remembers racing across Arlington to her pregnant daughter's apartment on the morning of Sept. 11. She could see smoke billowing from the Pentagon but was getting no information about what was happening in Arlington from her car radio.

"This made me realize that in an emergency, parents need immediate, good information. And three years later, we still don't have a system in place to provide that," said Garvey, who supports the radio station.

"Currently, commercial radio stations even have trouble getting snow days right. I'm looking for a place where we can control the information, where people can tune in, even if the electricity's out."

The idea for the station was developed this spring by the county's Citizens Corps Council, which was started after the 2001 attacks to help involve local residents in emergency preparedness, according to Jim Pebley, a member and former president of the Arlington County Civic Federation.

"After 9/11 and Hurricane Isabel, we found the second half of public emergency communications needed work. After you alert the public what's happening, you need to tell them what to do," Pebley said.

To that end, county emergency management officials have instituted several initiatives in hopes of better reaching citizens, according to Robert P. Griffin Jr., director of the county's office of emergency management. Officials and volunteers went door-to-door in June distributing emergency preparedness guides. They established ArlingtonAlert.com to send text messages about emergencies to pagers and cell phones.

Public safety experts say that the best warning systems combine such technologies as sirens, text messaging, Web alerts and radio or television broadcasting.

"Not one technology will reach everybody," said Kenneth B. Allen, executive director for the Partnership for Public Warning, a McLean nonprofit group that advocates for increased public notification systems across the country.

"Arlington is on the leading edge of warning. They have a very active committee of citizens working closely with county government. Having the Pentagon in the county has clearly accelerated these interests."

The county has hired Michigan-based Information Station Specialists to help obtain a 10-year license to operate from the FCC and install four transmitters.

Griffin said the county will be moving a portable transmission trailer to various spots throughout the county in the following weeks, and officials are asking for the public's help in testing the signals. They are hoping residents can tune into 1700 AM and then e-mail to let them know if they hear the signal.

Residents can obtain more information from the county's Web site, www.arlingtonva.us/oem.