For drivers who prefer to avoid having to make left turns, put Cedar Boulevard’s intersection with Morgan and Greenhurst drives on the list.
Morgan Drive extends east from Cedar, providing access to and from Mt. Lebanon Recreation Center, the adjacent municipal park and swim center, and eventually, Mt. Lebanon High School
Under normal circumstances, when recreational activities are ongoing and school is in session, traffic tends to back up considerably in Morgan’s left-turn lane as motorists wait for the traffic signal to change and the Cedar crosswalk to be clear of people.
“It’s creating a situation where they’re jumping that green light. The first car is trying to get through there and cut in front of any pedestrians,” traffic engineer Mike Haberman of Gateway Engineers said, likening the scenario to “a game of chicken.”
Mt. Lebanon commissioners approved modifications to the intersection to help improve the flow of vehicles. That includes reconfiguring Morgan’s approach to Cedar, with a left-turn-only lane flanked by one designated both for traffic proceeding straight onto Greenhurst Drive and turning right onto Cedar.
Also, the signal is to be modified to incorporate an advanced left-turn phase, during which vehicles will be unable to proceed from Greenhurst onto Morgan, and pedestrians are prohibited from crossing Cedar to the left of Morgan.
“Following that phase, pedestrians will get their walk interval to cross while there’s less traffic needing to make that left turn,” Kyle Brown, also of Gateway Engineers, said.
He and Haberman spoke during Mt. Lebanon Commission’s May 26 discussion session preceding the regular meeting, during which commissioners voted in favor of the changes. Both sessions were conducted remotely, and videos of the proceedings subsequently were made available.
The municipal traffic board reviewed the modification proposal in January and recommended the changes be implemented, based on studies conducted by Gateway staff members.
During the latest discussion session, Commissioner Mindy Ranney expressed concerns about people using the intersection’s crosswalks.
“It sounds like the traffic is backed up because of pedestrians, and that makes sense,” she said. “The kids are leaving high school, so there’s a decent amount of pedestrian traffic. Will there ever be a protected pedestrian walk phase of that traffic signal?”
Brown said that possibility had been investigated.
“But ultimately, it takes up so much time of your signal operations that it’s to the detriment of the vehicular traffic there,” he said. “In order to provide a phase just for pedestrians, then you lose a large portion of your cycle length to service the vehicles.”
Modifications to the intersection’s traffic signal will include a new feature to help guide motorists who are turning left from Morgan onto Cedar.
“When the green arrow goes away, it becomes a flashing yellow arrow,” Haberman said.
“So it enhances the driver’s awareness that, oh, I’ve got a flashing yellow arrow. I have to yield to oncoming traffic and pedestrians.”
Municipal manager Keith McGill explained the reason for the modifications appearing on the commission’s May agenda.
“Timing’s important here, because people, drivers, are creatures of habit,” he said. “So they know what lane they need to be in to make whatever movement they’re going to make. If you change that, there’s going to be an acclimation period. I would prefer to do that when we have a reduced volume of traffic, in terms of the school district and our park facilities, as well.”
He said mobile display trailers will be put into place to alert motorists to the changes.
According to Haberman, the state Department of Transportation must give the green light for changes to the traffic signal.
“I would say that we could get the signal plan approved and get a contractor on board, and specify that they have to have it done before school is back in session,” he said. “That shouldn’t be an issue.”