The Cranberry Blog

Cranberry’s Left-leaning Traffic Signal Patterns

By Duane McKee, Assistant Township Manager, Cranberry Township

Have you noticed a change in the traffic light patterns along Routes 19 and 228? It’s subtle, but it is one of many steps we have taken over the years to help improve traffic management along our major corridors.

During my tenure in Cranberry over nearly 20 years, I’ve been closely involved with putting a succession of new traffic management systems into place. Our first coordinated traffic signal system, 17 years ago, included 12 intersections; today, we coordinate more than 30 of them from a state-of-the-art Traffic Operations Center we opened earlier this year.

We completed our first signal project in 1994, which included the beginning of our fiber optic system that now connects 90% of our signals. It was the backbone for the current signal infrastructure, and it created a system we could update periodically. It was a simple, clock-driven, time-of-day plan. And for a while, it worked quite well. But as our needs grew, so too did traffic control technology – advancing from clocks, to closed loop systems, to traffic-responsive systems, and hopefully someday to automation. And Cranberry was an early adopter of all of them.

Those upgrades always involved Partners – PennDOT District 10, the Southwest Pennsylvania Commission (SPC) and private developers. Most motorists do not realize that traffic signals are owned by the municipality, even those on state highways. And they are expensive to operate and maintain. We could have chosen the route most communities have taken in regards to traffic signals which is to be reactive, but that is not an acceptable method to our Board of Supervisors. Our position has been and will continue to be proactive in managing the traffic that is passing through our community, no matter where it came from or where it’s going. That includes allocating the appropriate resources to properly maintain those systems. We also understood that motorists did not know or care which municipality they were driving through and simply wanted traffic flows that were as efficient as possible.  Poorly operated traffic signals costs motorists time and fuel. That is why Cranberry advanced the idea of managing traffic as a traffic-shed and successfully engaged our neighboring communities of Marshall and Adams Townships and Seven Fields Borough in that effort.

In our proactive position we’ve always understood that simply adding more asphalt could not be the ultimate answer to traffic congestion. We knew we would need to use all the tools in the box – particularly the ones involving more advanced signal management systems – to get the most out of the pavement already in place.

That turned out to be a good thing because in 2007, the State's General Assembly approved Act 44. That Act severely reduced funds for state highway capacity expansion projects. It left Cranberry to deal with its congestion issues, just like other Pennsylvania communites.  Fortunately, due to the foresight of our Board of Supervisors we were far better prepared for that responsiblity than most other communities – by building upon the electronic technology that was the backbone of our system.

Our most recent opportunity to implement new enhancements came with an SPC SINC-UP grant and a state Infrastructure Development Program grant (IDP). The SINC-UP grant was created to help communities manage their traffic signals to decrease driver frustration, cut emissions, and reduce fuel waste. Due to Cranberry Township's history of effectively operating our traffic signal systems, we were a perfect fit for the SINC-Up grant. The IDP grant was specifically targeted to help Westinghouse mitigate it's impact on our infrastructure, including the traffic signal systems. The IDP funds were used to acquire the most recent generation of traffic management software, which went on line earlier this month.

All of those efforts resulted in the timing and movement changes that were implemented on April 5. This was a team effort. The IPD grant was managed by the state’s Department of Community and Economic Development and the Community Development Corporation of Butler County. SPC pulled together a great team of traffic engineering, operation and technology specialists and our own signal technicians to develop and implement custom-crafted traffic signal patterns. Our new signal sequence, known as “leading lefts,” was part of that solution.

Leading lefts are not a common pattern in our area. So we published a lot of information about it. We used local media, our newsletter, variable message boards, and social media to prepare the motoring public for its rollout on April 5. Right now, we’re in the monitoring phase – tweaking the timings to refine our traffic model information and make sure it’s working as intended.

But you can prove it for yourself; drive the length of the Route 19 and Route 228/Freedom Road corridors and see if you notice the improved flow of traffic. Also, please pay attention to the other traffic corridors you travel, you may even get a better appreciation of what we are doing in the Cranberry Township area traffic-shed.

Keep an eye out for those leading lefts and if you notice something that needs a little more tweaking, I would appreciate it if you dropped me a note at Duane.McKee@cranberrytownship.org