Wednesday, March 17, 2010

Roundabouts Take Two

I was out for dinner Saturday night and the topic of roundabouts came up. Everyone was against them. I am a very pro roundabout person. Roundabouts are safer. Roundabouts increase traffic flow. Roundabouts are more economical. These are facts.

SAFETY: I stated that roundabouts are safer than intersections. If you can count, well then you have no choice but to agree with me. A standard two road intersection has 32 points of conflict. A standard roundabout has 8 points of conflict. Go ahead and count them.
According the Arizona Department of Transportation, roundabouts cut down the number of fatal crashes by 90%. Why? Roundabouts all but eliminate right angle (T-Bone) and head on collisions. I am actually shocked, I thought that number would be higher. They save lives and that can not be disputed.

A 2001 Insurance Institute for Highway Safety study of 23 intersections in the United States reported that converting intersections from traffic signals or stop signs to roundabouts reduced injury crashes by 80 percent and all crashes by 40 percent.



Similar results were reported by the New York State Department of Transportation, a 75 percent decrease in injury crashes and a 37 percent decrease in total crashes at 35 intersections that were converted from traffic signals to roundabouts.


People these are facts, not opinions. They work. I was just at the American Society of Civil Engineers Spring Technical Conference last week. I sat in on a break out session discussing this very topic. They analyzed newly constructed roundabouts in De Pere and Appleton. The results of studies from both cities backed up the information I am giving you here. They are safer and increase traffic flow. But they made it very clear, to get these results it is important for drivers to get familiar with them and for drivers understand how to navigate them.



Despite the demonstrated safety benefits of roundabouts, some crashes still occur. An Insurance Institute for Highway Safety study of crashes at 38 roundabouts in Maryland found that four crash types (run-off-road, rear-end, sideswipe, and entering-circulating) accounted for almost all crashes. A common crash type at both single-lane and double-lane roundabouts involved vehicles colliding with the central island. These crashes, which often involved unsafe speeds, accounted for almost half of all single-vehicle run-off-road crashes. Collisions occurred more frequently at entrances to roundabouts rather than within the circulatory roadway or at exits. There were no right-angle or head-on collisions, potentially severe crash types that commonly occur at traditional intersections. Institute researchers concluded that unsafe speeds were an important driver crash factor. That sounds to me like inattentive driving, i.e. pilot error.

But wait a second, it is possible that roundabouts are safer for pedestrians as well. It may surprise you but yes there are. Allow me to explain. In a roundabout, when pedestrians cross the roadway, they cross only one direction of traffic at a time. In addition, crossing distances are relatively short, and traffic speeds are lower than at traditional intersections. Studies in Europe indicate that, on average, converting conventional intersections to roundabouts can reduce pedestrian crashes by about 75 percent. Which would you rather have your child navigate? A roundabout or a standard intersection?

INCREASED TRAFFIC FLOW: One of the principles of a roundabout is that you don't stop. Vehicles are continuously moving. I have personally driven through roundabouts in Europe and they fly though them there without any problem. Here in the United States where roundabouts are new, I have noticed that far too many people come to a stop before entering the roundabout. It is a "YEILD" sign, not a "STOP" sign.
The fact that your vehicle does not stop means that not only do you get to your destination quicker, but you are also reducing vehicle emissions and fuel consumption. Here are three studies from the Insurance Institute of Highway Safety that back up this argument.
A study of three intersections in Kansas, Maryland, and Nevada, where roundabouts replaced stop signs, found that vehicle delays were reduced 13-23 percent and the proportion of vehicles that stopped was reduced 14-37 percent.


A study of three locations in New Hampshire, New York, and Washington, where roundabouts replaced traffic signals or stop signs, found an 89 percent average reduction in vehicle delays and a 56 percent average reduction in vehicle stops.


A study of 11 intersections in Kansas found a 65 percent average reduction in delays and a 52 percent average reduction in vehicle stops after roundabouts were installed.


These are again researched facts, not opinions. People once had the opinion that the earth was flat.

ECONOMICAL: The construction of a roundabout can be higher than traditional intersections. The main reason for this higher price would be real estate acquisition. But once the roundabout is built there is little more cost other than landscaping maintenance, and freshening up the pavement markings at regular intervals. Signalized intersections are far less cost effective in the long run. The cost of a standard two phase (which means just red yellow green in both directions running on a timer) can run around $60,000 in construction expense. Now if you get into more complex intersections with loop detectors, left turn green arrows, etc, you are getting into $150,000 - $200,000 range. That money comes from the tax payers. It comes from the tax on gasoline, vehicle registration, etc. This doesn't even take into account the electricity to run the lights, which run 24 hours a day, 7 days a week, 365 days a year. Try leaving all the lights in your house on for that time duration and see what your electric bill is.

Here is a website I found which actually has animations on how to properly navigate a roundabout. They are at the bottom of the page.

Still not convinced? Still hate them? Well I have some bad news for you. Any intersection in the state that is getting reconstructed and is being funded through the Wisconsin Department of Transportation goes through a roundabout feasibility study. That means if at all possible they will construct a roundabout.

I believe that the main reason that roundabouts fail is due to uneducated drivers. The next time you are approaching a roundabout, hang up your phone, turn off the radio and stop talking to the person next to you. Maybe if you were paying attention to your surroundings you would be better prepared to navigate the roundabout. As I was told when I first started driving, it isn't a right, it is a privilege.

Obviously there is going to be a learning curve with our driving public on the use of roundabouts. In the end, the reason people are against roundabouts is nothing more than ignorance. Get your heads out of the sand people. The sooner the driving public as a whole accepts roundabouts, the sooner they will come to understand that roundabouts are safer, increase traffic flow and more cost effective. I look forward to the time when you tell me that I was right.

2 comments:

Bubs said...

How can anyone not like an intersection with the same name as a "YES" song?

Anonymous said...

Its like you read my mind! You appear to know so much about this, like you wrote the book in it or
something. I think that you can do with a few pics to drive the message home a little bit, but other than that,
this is great blog. An excellent read. I'll certainly be back.


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