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Schaer Science: Roundabout
By Jessica Schaer
JOPLIN, MO.--- If the idea of driving through a roundabout seems foreign to you, that's because it is.
"We had our senior staff from Jefferson City, they went on a tour of Europe, France, England, just looking at different ones. And they saw some different concepts out there. One of them was a roundabout, and they decided to try some in different locations here in the US," said Dave Taylor, MoDOT Senior Traffic Studies Specialist.
After a trip nearly a decade ago, MoDOT officials saw a need for roundabouts in Southwest Missouri's congested intersections.
"We'll do a traffic study to see how much traffic's there. We'll also pull accident history and see if we're having severe accidents, if we're having rear-ends, or right angle type accidents," said Taylor.
Senior Traffic Studies Specialist Dave Taylor says he answers many questions about why a roundabout is necessary, since it's such a different concept.
"It is more efficient, it takes care of more traffic. We've always had a lot of complaints out here at Stone's Corner that, especially in the mornings or the afternoons, that it takes so much time for traffic to get through. Some people said they would sit through, you know, 5 of 6 cycles of traffic. You know, be waiting 10 to 15 minutes is what they would tell us," he said.
Single lane roundabouts are designed to handle 20,000 cars a day. Double lane roundabouts can handle 40,000 cars a day.
"With the roundabout, it's just continuous flow. You just come up and yield movement, if nobody's in the roundabout, you can go on. So, you know, maybe most of the time you're probably maybe 10, 15 seconds at the most, to wait to get through the traffic circle itself," he said.
Roundabouts are also more cost effective than traffic signals.
"Normally with the signal, usually with the equipment, you're probably talking 50 to 75 thousand dollars just for like the signal bases, the mast arm, the heads and everything, the equipment that goes into it," said Taylor
While roundabouts cost more than signals initially, they don't require much upkeep.
"What I've heard from our design is it's usually a little bit more to install a roundabout at the start, but over the years it will pay for itself, because we won't have to have electricians come out and monitor and put maintenance on the signal itself," he said.
Taylor's office yields calls from frustrated drivers, but he says that's because roundabouts come with a learning curve.
"Single lane's usually pretty good. You just have one lane to enter into, just get in there and go around. But with the dual lane, we'll really try to stress to people, we'll have overhead signs in advance of them, also have striping on the roadway," he said.
He also advises once you're in the roundabout, don't change lanes.
"If you're in the left lane of the roundabout as you're entering, that usually means you're kind of like at a regular intersection. You're going to be making a kind of a left going to the opposite, making a left hand turn to the other side. If you're in the right lane, usually you're only going to make a right hand turn or go straight on through," said Taylor.
Taylor stresses that it will take time for drivers to get used to a new roundabout. He reminds drivers to get in the lane they need to be in and yield to traffic already in the roundabout before entering.