The inbound Parkway West will close to all traffic from near Robinson Town Centre to Interstate 79 this weekend during construction work, the Pennsylvania Department of Transportation announced.

The full closing is the first of five scheduled this month and next as PennDOT completes work related to the $67.5 million "missing ramps" project.

Inbound traffic will be diverted from the parkway at the Route 22/30/60 interchange starting at 10 tonight. The detour follows Route 60/Steubenville Pike to I-79 south back to the parkway.

The contractor must reopen the parkway by 5 a.m. Monday.

On-ramps to the inbound parkway at Route 22/30/60, Campbells Run/Boyce Road and Ridge Road also will be closed this weekend.

The shutdown will affect service on the Port Authority's 28X Airport Flyer, which will detour via Park Manor Boulevard, Steubenville Pike and either I-79 or Campbells Run Road to the West Busway, but will continue to serve all regular stops, albeit with delays likely. The closures could be postponed by bad weather, but as of yesterday, the forecast called for a chance of rain tonight followed by fair weather for the rest of the weekend.

"We can handle some rain, which won't affect the milling [pavement removal] operations, which will be done first," PennDOT spokesman Jim Struzzi said. "For right now, the closure is a go."

Some 30,000 to 40,000 vehicles use the inbound parkway on a typical weekend day. Mr. Struzzi said PennDOT is not expecting major traffic tie-ups.

"It's a very simple detour and we'll have police there to keep things moving," he said. "Obviously, people will want to anticipate that there could be problems and allow themselves some extra time."

Traffic on the outbound side, including travelers going to Pittsburgh International Airport, will not be affected by this weekend's work.

No work is planned for Easter weekend. The tentative schedule for future closings is:

• April 17-20, inbound closure from midnight Friday to 5 a.m. Monday;

• April 24-27, inbound closure from 10 p.m. Friday to 5 a.m. Monday;

• May 1-4, outbound closure from midnight Friday to 5 a.m. Monday;

• May 8-11, outbound closure from 10 p.m. Friday to 5 a.m. Monday.

Crews will mill, patch and resurface the parkway from the Settlers Cabin interchange to I-79. The project will add a third lane in both directions from Campbells Run Road to I-79.

As part of the project, new ramps were opened in November at the I-79/Parkway West interchange to allow southbound I-79 traffic to connect to the westbound parkway and the airport, and linking the inbound parkway to I-79 north. Those ramps were omitted when the interchange was built more than 30 years ago.