Because of the narrow corridor and established communities the Parkway East flows through, it is difficult for the state Department of Transportation to widen the highway or improve the interchanges to make it less congested.

So PennDOT is taking the next best step: managing traffic so it flows better and improves safety for drivers.

The agency is developing a $45 million active traffic management system designed to make it easier to travel the 14 miles between Grant Street in Downtown Pittsburgh and Monroeville. The system will include more message boards and warning signs about lane closures; gates to close entrance ramps so vehicles don’t get trapped behind accidents; and variable speed limits to reduce rear-end collisions when free-flowing traffic approaches congestion. 

The project is among dozens of new items recommended for funding under the Southwestern Pennsylvania Commission’s draft Transportation Improvement Plan that is under review. The plan, which the commission will vote on June 26, is updated every two years and calls for $1 million for preliminary engineering next year and construction to begin the following year.

Todd Kravitz, PennDOT’s traffic engineer for Allegheny, Lawrence and Beaver counties, said the overall goal is to “harmonize” the driving experience on the highway by keeping traffic moving, even if it is at a slightly lower pace at times. Roadside electronic signs that reduce the speed limit by 5 to 10 miles an hour as traffic begins to get heavy have proven in other areas to reduce congestion, keep traffic flowing and avoid rear-end collisions.

“We have a big speed differential — people traveling the speed limit and people going only 25 or 30 miles an hour because of congestion,” Mr. Kravitz said. “That’s a recipe for crashes.”

Then when congestion or a crash brings traffic to a standstill, motorists who don’t know what lies ahead still try to get onto the highway. That’s why new signs will be installed approaching ramps to outline road conditions and gates will be available to close the ramp entrances so no more vehicles can get on the highway.

Other aspects of the system will include overhead markers such as a red X to indicate a lane ahead is closed and a warning system to alert drivers and police when a vehicle drives the wrong way on a ramp to get onto the highway.

“We’re really trying to improve the operation and improve the safety of the parkway,” Mr. Kravitz said. “When we have people moving about the same speed, that will have it move smoother.”

The entire system would be controlled from PennDOT’s traffic management center, which has cameras that show road conditions almost instantly to allow for quick changes. Whatever speed the center sets becomes the legal speed limit and motorists can be cited if they are caught driving above that limit.

Mr. Kravitz said the agency believes the variable speeds will be effective in slowing drivers down because of the department’s proven success with slowing traffic in work zones with electronic enforcement. The parkway won’t have electronic enforcement, Mr. Kravitz said, but motorists have gotten used to following directions to reduce their speed through the work zone program.

The Parkway East program is an outgrowth of a 2018 study by PennDOT to find solutions to highway congestion. District Executive Cheryl Moon-Sirianni mentioned other projects in store for the Parkway West, like remaking the interchanges at Carnegie, Green Tree and Banksville to improve traffic flow. Those changes aren’t possible on the Parkway East.

“We were stuck with very antiquated interchanges on the Parkway East,” she said. “You just can’t build out there like you can along the Parkway West because there isn’t any room. This is our best opportunity to make improvements on the Parkway East.”

Traffic on the Parkway East has returned to about 90% of pre-pandemic levels, Mr. Kravitz said, which means about 45,000 vehicles a day use it each morning and again in the evening.

Ed Blazina: eblazina@post-gazette.com, 412-263-1470 or Twitter @EdBlazina.

First Published: May 23, 2022, 10:08 p.m.
Updated: May 24, 2022, 10:15 a.m.