Motorists looking to avoid road construction delays and detours may want to limit their driving from dusk to dawn.

The Pennsylvania Department of Transportation is working on several projects during off-peak hours, ranging from resurfacing of Interstate 70 east of Washington, Pa., to the Parkway East/Interstate 376, where work resumes from 9 p.m. to 5 a.m. today through Friday morning inbound from Business Route 22, Wilkins, to the Edgewood-Swissvale interchange.

Several ramps also will be restricted on the parkway as part of ongoing reconstruction of the three-mile section, including closing of two outbound on-ramps -- Route 8 from Wilkinsburg and Route 30 from Forest Hills.

The I-70 resurfacing project will limit traffic to one lane for about 10 miles between the Kammerer interchange and the I-79 south junction from 8 p.m. to 8 a.m. Sunday through Aug. 29.

Some other nighttime work affecting major traffic arteries includes:

Liberty Tunnels -- Outbound lanes are closed from 10 p.m. to 6 a.m. Sundays through Thursdays. PennDOT is spending $5.3 million on repairs and improvements, including rebuilding the tunnel portals. During the closures, traffic headed to Route 51 and Route 19 will be detoured around the outbound tunnel via McArdle Roadway over Mount Washington.

Fort Pitt Bridge -- Lanes are being closed in both directions from 7 p.m. to 6 a.m. for another week or so for a $26,000 wash job. To minimize traffic impacts, PennDOT is starting work on the outbound deck in early evening and moving to the inbound lanes after traffic volumes subside. All ramps remain open.

Parkway West, Green Tree -- The highway is pinched to a single lane in each direction around the Green Tree interchange from 8 p.m. to 6 a.m. through tomorrow morning during painting and repairs. In addition, the outbound exit ramp to Greentree Road is closed during the same period, as is the outbound entry ramp from Greentree Road toward Rosslyn Farms.

Parkway West, Carnegie -- Lanes are being closed from Carnegie to Rosslyn Farms from 8 p.m. to 6 a.m. for bridge repairs, except on Friday night, when lanes will be closed through noon Saturday.

Parkway West, Robinson -- Shoulders in both directions and several ramps will be closed from 8 p.m. to 6 a.m. today through tomorrow morning for a two-mile resurfacing project. Detours will be posted.

PennDOT has advised motorists to slow down and expect changing traffic patterns over the heavily traveled stretch between Route 60/Airport Expressway and Downtown for what at times can be four simultaneous state-sponsored construction and maintenance operations.