Expect more traffic on Humphrey Street later this year but the plan is to maintain two-lanes open whenever possible, a National Grid spokesman said.

On Wednesday, selectmen approved the utility company's project — installing about three-quarters of a mile of underground conduit to carry electrical lines along Humphrey Street.

National Grid wants to start work by April 1, said National Grid Engineer Phillip Courcy. The project would end in late fall, he said. Road crews would return in the spring of 2013 for finish paving.

The underground lines are intended to increase capacity and reduce the number of outages, said John Upham, a company spokesman.

The utility has had problems with outages in that area, he said.

Selectman Jill Sullivan lives in that vicinity and attested to the problems.

"I hate to see the street dug up for six months but we've had a lot of outages," she said.

The Humphrey lines will extend from the intersection with Cedar Terrace — near Fisherman's Beach — to the Swampscott/Lynn line.

The work will start at the Cedar Terrace end and head toward Lynn, he said.

Crews will work in sections, opening up a four-four wide trench anywhere from 20 to 60 feet long. At the day's end they will fill the section, Courcy said.

He expects the work day to start at 7 am and end at 3:30 pm.

Police will work traffic details.

Company spokesman John Upham said after the meeting that there will be additional congestion on Humphrey.

He also said access to businesses and residences will remain open.

Wednesday's meeting was a public hearing.

Property owner Jayne Orloff-Carey asked if National Grid could bury the transformer that is on the lot where the former Gateway Building stood. Her family's building burned on March 1.

Courcy said he would look into the request but the transformer is unrelated to the construction project.