Sara Lavoie, a spokeswoman for the state Department of Transportation, told The Republican the work -- a roughly $4 million effort to replace signs along the stretch of highway between Longmeadow and West Springfield -- would continue through Thursday.

Lavoie said the work was scheduled for off-peak hours and not during the morning and afternoon or evening commutes, with overhead sign work scheduled for the overnight hours.

Still, a long traffic backup on the highway persisted from late morning through mid-afternoon Monday, with drivers only inching along when the traffic moved at all.