Transcript for Roundabouts in Kansas Video

Narrator
If you have never driven a modern roundabout chances are good you will soon enough. They have been used successfully throughout the world for more than 20 years and beginning in the 1990's they have been used across the United States in a wide range of environments including urban and rural settings. The Kansas Department of Transportation and local governments are turning to this traffic control device more often as means to manage traffic by reducing conflicts and increasing intersection capacity, controlling speed, and most importantly reducing crashes at intersections. Research has shown that roundabouts are considerably safer than typical intersections.

Dr. Eugene Russell, PE, Professor Emeritus, Civil Engineering Kansas State University
Classic study was the one done by the Insurance Institute for Highway Safety where they found roughly a 40% reduction in all crashes and about a 70% reduction in injury crashes. Which to me is the most significant advantage of a roundabout is the reduction in injury crashes and a projected 90% decrease in fatal crashes.

Narrator
Dr. Russell's study of roundabouts in Hutchinson, Olathe, Manhattan and North of Paola revealed another advantage of roundabouts, they greatly reduce delays.

Dr. Eugene Russell, PE, Professor Emeritus, Civil Engineering Kansas State University
And were finding roughly 50 to 80% reduction in stopping and delay.

Narrator
Its important that you know what they are and how to safely drive through them and that is what this video is all about. Lets start with what a modern roundabout is not. It is not a traffic circle and it is also not a mini circle - a traffic calming device used in residential neighborhoods.

David Church, Chief of Traffic Engineering, Kansas Department of Transportation
A mini circle is really a circular object placed in the middle of an intersection without really changing anything else at the intersection and its really an obstacle in the middle of an intersection to get you to slow down because you are not going to be able to drive over it and you will have to drive around it. A roundabout is put in to slow you down to get a lot more traffic thru an intersection and basically improve the intersection and invite traffic to come through it instead of trying to divert.

Narrator
The first major difference between mini circles and modern roundabouts is that roundabouts have a yield at entry rule. This means traffic entering the roundabout must yield to traffic already in the roundabout. Another key difference between roundabouts and traffic circles is that modern roundabout use deflection. They have splitter islands in the approach lanes forcing the drivers to enter the intersection at safe angles and slower speeds. The third major difference is that roundabout sometimes have a flared entry the entry often widens or flares from one or two lanes of traffic to two or three lanes at the yield line to allow for increase traffic flow. Those differences help us define what a modern roundabout is; a roundabout is a circular intersection with a raised central island and splitter islands in the approach lanes to slow and control the direction of traffic. Traffic traveling within the roundabouts has the right of way to vehicles approaching the intersection. Approaching vehicles yield at the entry until an opening in the roundabout is available, once in the roundabout vehicles circulate around the center island in a counter clockwise direction until they reach the desired street intersection.

Narrator
Roundabouts are being designed and built as an alternative to the tradition intersection for many reasons, however the main reason is safety. Roundabouts can reduce the number of collisions by 50% to 90% compared to a traditional four way intersection. This significant reduction in accidents is largely due to the lower number of conflict points. Conflict points are those areas where collisions could occur as traffic paths cross. At a traditional four way intersection there are 32 potential conflict points in a roundabout that number is reduced to 8 and none of them are at right angles.

David Church, Chief of Traffic Engineering, Kansas Department of Transportation
Now at a roundabout because you have lessened that angle the vehicles can strike each other you have really lessened the impact to the driver and because of that you have really dropped their chance from being injured. What you see when you put in a roundabout is you will still have some accidents but they tend to be more side swipe, rear end at a slow speed and your injury accidents just drop.

Narrator
Roundabout intersections also enhance pedestrian safety. Reduce vehicle speed, reduce pedestrian-to-vehicle conflict points, and reduce length of crossing all contribute to a safer intersection for pedestrians. Roundabout intersections are able to handle a higher number of vehicles than standard intersections and still reduce delays. A higher number of vehicles are able to travel through the roundabout in less time because they yield instead of stopping at a traffic light or stop sign.

David Church, Chief of Traffic Engineering, Kansas Department of Transportation
You hate to sit at a stop sign or traffic signal with a red light when no traffic's coming and just be there for no reason. So the improvement to delay is so important that its all the matter of the traffic flowing through.

Narrator
A study of roundabouts in Kansas confirmed the reduction in delays. Here are a couple of examples:

• At the Rogers and Sheridan roundabout in Olathe the average intersection delay during the morning rush dropped from almost 38 seconds to about 12 seconds and that is a decrease of 69%. In the evening rush the delay dropped from more than 90 seconds to about 12 seconds a reduction of 87%.
• In Paola on K-68 the intersection delay dropped from 19 seconds to 5 1/2 seconds a reduction of more than 77%.

Narrator
Roundabouts are more attractive than traditional intersections because the large center islands can be landscaped. Now that you know what they are and why they are safer, lets talk about how to drive a roundabout. As you approach the roundabout you will notice a roundabout ahead sign with an advisory speed sign posted below it followed by a yield sign ahead. Once you reach the entrance of the roundabout you will see a yield sign and a dash entrance line painted at the entrance. As with any intersection you should watch for pedestrians and bicyclists and be prepared to stop if necessary. A conventional roundabout will have one way signs posted around the center island guiding you in a counter clockwise direction, since traffic is moving in one direction you yield at the entrance and look primarily to your left and watch for on coming traffic. When a gap opens in the traffic and you are comfortable that you can safely merge you may them proceed into the roundabout. As you approach your exit, turn on your right turn signal and once again watching for pedestrians and bicyclists exit the roundabout.

Narrator
If you are in or near a roundabout when an emergency vehicle approaches, clear the roundabout to allow the emergency vehicle to enter and exit the roundabout. If there is not enough time to clear the roundabout, get over as far as you can to clear the road but make sure you are not blocking any of the intersecting roads and in case you are are wondering roundabouts are designed to handle large emergency vehicles such as fire trucks. Most roundabouts were also designed to handle trucks and school busses, some people see a truck tire go over the apron in the middle or see tire marks there and they think the roundabout is too small. Actually the apron called the truck apron is there just for that reason to give trucks and busses the extra room they need. So if roundabout are so wonderful why do you hear people complain about them? Chances are good they have never driven one.

Dr. Eugene Russell, PE, Professor Emeritus, Civil Engineering Kansas State University
In Hutchinson there was a person or persons that formed a group an organized group called (CAR's) Citizens Against Roundabouts and they put up billboards and lawn signs and they were very vocal and very adamant against them and the Hutchinson roundabout is one of the biggest success stories in the country. Now before they had a two way stop they had 19 right angle collisions, the 19 previous ones and 6 were injury accidents. In two years since it has been in they have had about 6 what I call fender benders and no injury accidents.

Dennis Clennan, Public Works Director, Hutchinson
Accidents are down from what they were before the roundabout was built and matter of fact, one of our City Councilman who was opposed to the roundabout made a comment a few weeks ago that things are looking pretty good and that maybe we should look into some more.

The Kansas Department of Transportation in cooperation with Kittleson & Associates and the Kansas Roundabout Committee have published the Kansas Roundabout Guide. This guide is a supplement to the Federal Highway Administration document, Roundabouts: An Informational Guide. The Kansas Roundabout Guide was developed to promote consistency with modern roundabout design in Kansas. To obtain a copy of this guide or other information on roundabouts please access KDOT's web page or contact the KDOT's Bureau of Traffic Engineering. We hope this video has helped you understand a little more about modern roundabouts. Something you will certainly see more of in the coming years.