On the first workday after Isabel blew through the state, Marylanders will find schools closed, traffic signals out and thousands still trying to cope without power.

Officials in Anne Arundel, Harford, Calvert, Prince George's, Charles, St. Mary's, Montgomery and Baltimore counties decided to keep their schools closed today because of buildings that lacked power and streets that were blocked by downed trees.

Seventeen Baltimore City schools were also expected to be closed, as well as seven to 10 in Howard County, depending on the progress of repairs overnight.

Four days after Isabel struck, thousands will be leaving homes without electricity to drive on streets clogged with debris and unprotected by working traffic lights at some intersections.

About 175 traffic signals remained out statewide last night, including 42 in the city, according to city and state officials. By law, such intersections become four-way stops.

All trains and buses operated by the Maryland Transit Administration were scheduled to be back in service, said Richard Scher, an MTA spokesman.

Amy London of Cedarcroft was not looking forward to the first morning going back to work.

"It's a bad combination not having a hair dryer or a coffee machine," said London, 52, yesterday while taking a break from pumping water out of her home's flooded basement on Pinehurst Road.

London will have to drive her 16-year-old daughter and 10-year-old son to school before going to her job at Agora Publishing in Mount Vernon.

Her work, however, will be a break from a home without power, she said.

"Luckily, we're out of the house for nine hours, so you stop thinking and worrying about it," she said.

Officials said they decided yesterday to close schools because many buildings were without power and many streets were flooded and blocked by tree limbs.

"Kids can't walk to the bus stop or to their schools because there's so much flooding and downed trees," said Douglas J. Neilson, a Baltimore County schools spokesman.

At least 30 of Baltimore County's 163 schools remain without power and numerous roads are impassable, Neilson said.

Damages from Isabel are still being assessed but are certain to run into "the tens of millions of dollars," said Gov. Robert L. Ehrlich Jr.

Yesterday, he signed an agreement with the Federal Emergency Management Agency to allow businesses to apply for federal financial aid to help pay for the cleanup.

Clearing roadways and debris continued to be a major problem in some areas.

Ehrlich said 14 state roads remained blocked yesterday because of flooding or downed trees, with most of the closed roads in Dorchester, Prince George's and Baltimore counties.

Mayor Martin O'Malley said the storm is costing the city $600,000 per day to pay for police, firefighters, public works and other emergency workers.