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Cambria County has its first roundabout — Uh, oh

… first cloverleaf becomes a roundabout

In the early 1950s, the Geistown Cloverleaf became one of the first ones in Cambria County. Now, that cloverleaf has now become a roundabout, from what I have seen on social media, it is going through growing pains.

A video posted on Facebook showed a car going the wrong way on the newly opened roundabout. Getting used to these is going to take some time.

Why use these ridiculous creatures?

The benefits

Using roundabouts apparently have some value. I never saw them until I moved to the Upper Midwest, where they are predominant. My question was why,

Roundabout benefits

Improve safety

Studies have shown that roundabouts are safer than traditional stop sign or signal-controlled intersections.

Roundabouts reduced injury crashes by 75 percent at intersections where stop signs or signals were previously used for traffic control, according to a study by the Insurance Institute for Highway Safety (IIHS). Studies by the IIHS and Federal Highway Administration have shown that roundabouts typically achieve:

  • A 37 percent reduction in overall collisions

  • A 75 percent reduction in injury collisions

  • A 90 percent reduction in fatality collisions

  • A 40 percent reduction in pedestrian collisions

Washington State Department of Transportation

The Eastern United States has been slow to engage in the roundabout craze. However, almost seven years ago, engineering firms in Cambria County, Pa. were asked to improve the traffic in a growing Richland Township and Geistown Borough.

Here is what transpired,

What began in 2014 as a pavement project has morphed into a corridor project that enhances safety and mobility along Route 3016 in Geistown Borough and Richland and Stonycreek Townships. Other design elements of the 1.75-mile project include a road diet concept along Route 3016, signal upgrades at five intersections, access management, elimination of a structure, addressing drainage concerns and 3,400 feet of sidewalk.

Built in 1951, the original engineers of the Geistown Cloverleaf foresaw a different evolution of the area's community and roadway network. Today's configuration consists of a partial cloverleaf interchange connecting Route 3016 to Route 756 and a divided, four-lane Route 3016 within a neighborhood and business setting. The arterial provides connectivity between the City of Johnstown, it's western suburbs and US 219.

When District 9 solicited engineering services for the project, the scope was left open-ended and expectations were to eliminate the existing median curb with approximately 2,000 feet of paving. To the district's surprise, almost all firms suggested an alternatives analysis phase with conceptual designs including a roundabout, SPUI, realignments and an at-grade intersection.

Pennsylvania Department of Transportation

Other advantages

Reduce delay, improve traffic flow

Contrary to many peoples' perceptions, roundabouts actually move traffic through an intersection more quickly, and with less congestion on approaching roads. Roundabouts promote a continuous flow of traffic. Unlike intersections with traffic signals, drivers don’t have to wait for a green light at a roundabout to get through the intersection. Traffic is not required to stop – only yield – so the intersection can handle more traffic in the same amount of time.

Studies by Kansas State University measured traffic flow at intersections before and after conversion to roundabouts. In each case, installing a roundabout led to a 20 percent reduction in delays. Additional studies by the IIHS of intersections in three states, including Washington, found that roundabouts contributed to an 89 percent reduction in delays and 56 percent reduction in vehicle stops.

Less expensive

The cost difference between building a roundabout and a traffic signal is comparable. Where long-term costs are considered, roundabouts eliminate hardware, maintenance and electrical costs associated with traffic signals, which can cost between $5,000 and $10,000 per year.

Roundabouts are also more effective during power outages. Unlike traditional signalized intersections, which must be treated as a four-way stop or require police to direct traffic, roundabouts continue to work like normal.

Less space

A roundabout may need more property within the actual intersection, but often take up less space on the streets approaching the roundabout. Because roundabouts can handle greater volumes of traffic more efficiently than signals, where drivers may need to line up to wait for a green light, roundabouts usually require fewer lanes approaching the intersection.

Washington State Department of Transportation

So, maybe these will take off in Cambria County. For now, though, it will take some adjustment.

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