Dan Cessna, head of Pennsylvania Department of Transportation District 11, has received some negative feedback as word spread that Interstate 279/Parkway North will undergo construction this summer.

"It's hard for people to understand why we're doing this because highway and bridge preservation haven't been the philosophy here, partly because resources weren't available," he said at a news conference last week. "But what we're about to do will extend the pavement life by eight to 10 years."

West Mifflin-based Trumbull Corp., the same firm rehabilitating the Parkway East, will start an $11.2 million rehabilitation of 8 miles of I-279 a week from today. The high occupancy vehicle lanes will be fixed first, namely around McKnight Road where the deterioration is worst.

Later, work will shift to the mainline, eventually covering 8 miles between East Ohio Street on the North Side and Camp Horne Road in the North Hills.

The entire project is not expected to be finished until late October or early November. When the HOV lane repairs are finished, PennDOT will waive the two-to-a-vehicle rule and open it to everyone for the balance of construction.

The stretch of concrete roadway, opened in 1989, now carries an average of 110,000 vehicles a day. It has become one of the region's busiest corridors, helping promote business and residential growth in suburbs such as Ross, Marshall and Cranberry.

Mr. Cessna said if PennDOT allowed normal wear and tear to continue, the department would eventually end up doing more extensive, more disruptive repairs costing at least 10 times as much money.

"Consider this putting a new roof on the house after 19 years and preserving a very expensive asset," he said. "Most traffic disruptions will be of relatively short duration. We're telling motorists ahead of time so they can think about it. Maybe they'll want take buses or car pool, given the price of gas."

He said PennDOT engineers recognize the importance of the I-279 corridor, which is why they want to keep it in exceptional condition.

During the first phase, after the HOV lanes are closed at 9 a.m. next Monday, ride-sharing motorists and Port Authority buses will be diverted to the I-279 mainline or East Street, a parallel road serving local traffic.

During the second phase, starting after the Fourth of July, two lanes will be open to traffic initially. Then, only one of the three southbound lanes will be open.

When I-279 inbound is down to the single lane, the HOV will operate in the inbound direction only, without the minimum occupancy requirement.

The third and final phase will cover the northbound mainline. It won't get under way until PennDOT finishes the other side of the six-lane highway through the East Street Valley.

The Port Authority will continue to provide bus service to and from PennDOT's Perrysville park-and-ride lot, but riders are advised to expect congestion and delays.

The project consists of repairing concrete slabs and 13 bridges, including the I-279 overpass of McKnight Road that's rated structurally deficient under federal rating standards. Drainage, guide rail and pavement markings also will be improved.

Next year, PennDOT plans to the same type of highway preservation work from Camp Horne Road north to the I-79 Junction in Franklin Park.