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Research: 'Traffic circles' dangerous for cyclists

JNL

Cyburbian
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2,449
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25
Well it's not like we didn't know this already, but thought the research might be of interest. The researcher works for the same company I do.

ROUNDABOUTS RISKY FOR CYCLISTS, PEDESTRIANS, MOTORCYCLISTS
Wellington, Feb 11 - Roundabouts are risky places for cyclists, motorcyclists and pedestrians, according to research by Auckland University Master of Engineering student Nathan Harper.

Mr Harper recorded information about 95 urban roundabouts , ranging from simple single-lane intersections to the multi-lane roundabout at Panmure in Auckland. Roundabouts had a lower injury accident rate than other intersection types, including traffic lights, he said in a statement.

But cyclists, motorcyclists and pedestrians faced a significant injury crash risk at roundabouts. Cyclists were involved in 24 percent of injury accidents, with pedestrians in 15 percent and motorcyclists in 10 percent. ``These injury figures are disproportionate to the number of cyclists, pedestrians and motorcyclists who are on the roads. These users are more likely to be seriously injured in a crash, as they don't have the car to protect them in an accident,'' he said. Cars entering roundabouts and failing to give way caused 45 percent of injury accidents, with other accidents relating to loss of control (19 percent), rear end crashes (16 percent) and sideswipe crashes (5 percent).

The research aimed to make roads safer by predicting which planned roundabouts would be susceptible to accidents. The work, presented at transportation conferences in Wellington and Seattle, examined the geometry of the roundabout and traffic flows to predict accidents. It could be used to build accident prediction models to fit in with a new funding model from road funding agency, Transfund, aimed using accident prediction to fix problem areas before accidents happened, Mr Harper said.

His research is intended to be integrated with a major government-funded research project in the United States to examine roundabout installation. The US has traditionally been shy of roundabouts and now has only about 300 such intersections, compared to about 500 in this country.

Roundabouts were a European concept and had been resisted in the US so far because of concerns for the safety of cyclists and pedestrians, and also because people there did not understand them, Mr Harper said. Roundabouts worked best in lower traffic flow areas and in situations without a dominant road.

As well as doing his studies, Mr Harper has a full-time job in the traffic engineering department at Opus International Consultants in Auckland. The company sponsored him during postgraduate studies as part of a bright future enterprise scholarship, administered by the Foundation for Science, Research and Technology.
 

passdoubt

Cyburbian
Messages
407
Points
13
Traffic circles are dangerous for motorists too. Whenever I've had to drive through them in New Jersey it's just seemed like total anarchy. I just grip the steering wheel tightly and cautiously roll through, hoping somebody doesn't hit me. I don't understand their logic in the least bit.
 

JNA

Cyburbian Plus
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25,568
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59
A NJ claim to fame for originating the traffic circle or roundabout in 1925.
Growing up in NJ I too have exprienced them as a driver.

On a past visit, I think I read that in ? Elizabeth on 1 & 9 ? they cut through the circle making it a 4-way intersection with the circle portions being either continuous right turn lanes or becoming the Jersey jughandle left turn.
 

H

Cyburbian
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2,850
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24
I will submit that, like with anything else, they are only really dangerous when not used properly. If there is a bike lane, it should be no different for the cyclist than a crossroads intersection. And yes, I do ride bikes.
 

Rumpy Tunanator

Cyburbian
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4,473
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25
JNA said:
A NJ claim to fame for originating the traffic circle or roundabout in 1925.
Growing up in NJ I too have exprienced them as a driver.
We had them before that, and just got done restoring them. http://www.richmondavenue.org/a_brief_history_of_ferry_circle.htm
http://www.kleinhansca.org/sc.htm


1895



They sure slow traffic and keep things moving, I can't recall any recent accidents as a result of them. Most of the ped/bike accident reports I've worked on, are at your standard intersection.
 

jresta

Cyburbian
Messages
1,474
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23
jersey born & raised here. I cut my driving teeth on the eatontown, asbury, and brielle circles. Navigating a circle was actually part of my driving test.

but traffic circles and roundabouts are not the same thing. a traffic circle is multi-laned. A roundabout is one lane. Circles, those that are left, are always at the confluence of two state highways where local roads also intersect.

They actually handled the volume very well, the problem was the accidents. The DOT's solution to growing congestion (as is an engineer's solution to everything) was "make it bigger". This just made traffic move faster and served to make accidents more catastrophic. The problem is that drivers here have never been taught circle etiquette, you have to learn it as you go along and if it's not something you use everyday it could take you a lifetime to learn so . . .

#1 - DO NOT STOP! Do not stop as you approach the circle and certainly don't stop once you're in the circle. Stopping causes accidents.

#2 SIGNAL. Use your left signal when entering the circle, quickly move to the inside lane and use your right signal to exit. If you have to do a lap to get out then do it but DO NOT STOP! The National Lampoon's tale was greatly exagerated.

#3 MERGE. the whole idea of a circle is a merge. wait your turn.

#4 DON'T SPEED. Just because it's round doesn't mean you're Dale Earnhardt all of the sudden.

#5 DON'T PANIC. This is no different than a heavy merge onto a slow moving freeway then right back off again. Yes, it looks different, but you CAN do it.

as you can see modern drivers are incapable of following any of these rules. So Circles were being torn up everywhere. Then the engineers realized what a disaster the intersections they replaced them with were so now they're on to "right-sizing circles" rather than dismantling them.
 

iamme

Cyburbian
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485
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14
Now, that article gave percentages of peds, cyclists etc in crashes but I have a question about the logic. From what I've heard, there is a reduction in auto accidents in traffic circles/roundabouts, now if the number of auto accidents goes down and the rest stay the same, couldn't the lower crash numbers for auto just make the other accident numbers look large by comparison. Also they never said if the number of accidents went up for peds, cyclists etc. I would just like to reiterate that I don't have any firm numbers in front of me to give a real counter-point to this article.
 

donk

Cyburbian
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6,970
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30
JNA said:
A NJ claim to fame for originating the traffic circle or roundabout in 1925.
Growing up in NJ I too have exprienced them as a driver.

On a past visit, I think I read that in ? Elizabeth on 1 & 9 ? they cut through the circle making it a 4-way intersection with the circle portions being either continuous right turn lanes or becoming the Jersey jughandle left turn.
All up and down "Killer" Route 9 they have implemented these "jug handles". I have family in Lakewood/Brick Township and have experienced them first hand. I like them, no left turns required in busy traffic. They also have the "jersey barrier" to prevent left turns. (concrete median)

More on topic, I can 't imaging trying to ride a bike through a traffic circle. At a presentation at the CIP conference the presenter suggested having crossing points for pedestrians and cyclists well before the circle. He hypothesized that the slowing for the pedestrians would actually make entering the circle easier as it defined the entrance to the circle area.
 

jresta

Cyburbian
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1,474
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23
again, traffic circles and roundabouts aren't the same thing. Even with the ample shoulders i'd never ride my bike on a state/us highway in NJ. People are going way to fast and the shoulders are accel/decel lanes. A traffic circle would be the last place i'd think of taking a bike.

Here is an explanation from Somerset Co., NJ planning on the difference -
"Unlike roundabouts, traffic circles are not designed to a set of guidelines that make the entry controls the same for every traffic circle a driver might encounter. Many are designed as a "weave" intersection with large radii and straight entrances, which promote high-speed movements. With the higher speeds, large gaps are required in the circulating traffic before vehicles can enter the circle. This creates long waiting times; long queue lengths and results in more sever accidents. Some traffic circles require circulating traffic to yield to vehicles entering the traffic circle. Giving priority to entering vehicles, these circles tend to "lock up" with higher traffic volumes."


The jughandle was never an answer to the traffic circle. One has to consider the population density of NJ and that we've had a certain level of commercial development and accompanying traffic since the 50's that many cities and states are just coming to know. An effort was made to lower the number of head on and side-impact collisions on state routes by getting rid of the "suicide lane" thus eliminating dangerous left-hand turns. The jersey barrier was created. The jug handle was a way to get people through an intersection without the left turn.
It operates much more like a freeway than a typical arterial with all turning movements taking place from the right lane.

here's the edge of a circle near the AC airport. You can get a sense for the radius of this thing. Nothing like a neighborhood roundabout.


Here's another monster near AC - you could easily have two football games inside this one.


here's what the NJDMV has to say about it - which is to say - "there are no rules"

>>There is no set rule for driving into and around a traffic circle in New Jersey. Common sense and caution must prevail at all times.

In most cases, the circle's historically established traffic flow pattern dictates who has the right of way. If a major highway flows into and through the circle, it usually dominates the traffic flow pattern and commands the right of way. Traffic control signs, such as stop or yield signs, at the entrances to the circle also govern who has the right of way.

Whenever a motorist is in doubt concerning who has the right of way, the motorist should exercise extreme caution and remember the basic rule governing any uncontrolled intersection - the vehicle to the left shall yield the right of way to the vehicle approaching from the right.

Remember, never enter a circle without checking all signs and determining the intentions of the operators of any other vehicles already operating within the circle. Caution must be the guiding rule and the driver should never assume that he has the right of way. <<
 

JNL

Cyburbian
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2,449
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25
jresta, thanks for the clarification of definitions. We call all types roundabouts here and I thought traffic circles was the equivalant US/Canadian term.

We have a lot of roundabouts here and they mostly work pretty well. People are used to them. I drive through 3 every day on my 20 min journey to work. One has just been upgraded to 2 lanes but doesn't seem to cater well for cyclists. Could get pics if people are interested?

iamme - very good point. Will try to get more info on the research.
 

ilikefish0

Cyburbian
Messages
204
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9
What about a roundabout with grade separation? In the new orleans area, there is one where one road passes over the circular portion and the other passes under. Both roads can go straight and the circulating action still happens. Does this type exist anywhere else? What implications does this have for the cyclist.

PS Circulating vehicles have the right of way. Vehicles merging onto the circle must yield. At least at this intersection.
 

Rem

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1,524
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23
ilikefish0 said:
What about a roundabout with grade separation? In the new orleans area, there is one where one road passes over the circular portion and the other passes under. Both roads can go straight and the circulating action still happens. Does this type exist anywhere else? What implications does this have for the cyclist.
Thesed are becoming the typical alternative to a clover leaf in Australia. There are two I can think of within the LM/Newcastle area. In one there is no special help for cyclists. In the other there are designated crossing locations and a grade seperated pathway for pedestrians and cyclists. he second example isn't a simple circle either - it is more peanut shaped.
 

freewaytincan

Cyburbian
Messages
125
Points
6
You know, the words "improperly" and "traffic circle" have combined, causing me to recall these images from Mr. Wonderful's site (with original comments):


Look how the City of Phoenix has spent your tax dollars. Isn't this a beautiful waste of metal?


Mr. Wonderful came upon this oddity while traveling the backroads of Northeast Phoenix, Arizona. As of early March 2001, this atrocity has apparently been dismantled and returned to the City of Phoenix equipment yard.

The City of Phoenix in another failed attempt at being "trendy". Idiots. I didn't know whether to laugh or cry when I saw it. I think I did both...
 

plankton

Cyburbian
Messages
751
Points
21
I drive through a two-lane traffic circle on my way to and from work each day and think it's great. After much prodding from the local city council, the highway dept. decided to install a "roundabout" instead of a traffic signal at this intersection and the thing works beautifully.

To avoid conflicts, the bike lane was routed away from the circle itself with a striped road crossing a few hundred feet away. Seems to be working well.

Wish I had a picture of it.....
 

freewaytincan

Cyburbian
Messages
125
Points
6
I should clarify. Traffic circles are fantastic, they really are. Got one in a business area surrounded by towers about half a mile east of here, and of course, Addison Circle. My example was just of how it is done wrong many times.
 

LMJ

Member
Messages
16
Points
1
I live in Louisiana, and had never seen a roundabout in the state until I moved to my current location where I negotiate one twice a day. When I first arrived, I think the thing was still very new because drivers were treating it like a four-way stop. Fortunately I believe most drivers have finally caught on and I no longer feel fearful of ignorant drivers at each approach....
 
Messages
94
Points
4
here's another article about round-a-bouts!

Are roundabouts really safer?
Studies are unclear when it comes to pedestrians and bicyclists, who lie at the heart of the current debate.

By Lisa Rab

SARASOTA -- Sprinting across five lanes of traffic at Gulf Stream Avenue and U.S. 41 is a daily gamble for Sara Crowell, who jogs from Marina Jack to Lido Key most evenings around sunset.

"There's not a good time to cross -- ever," the 21-year-old New College student said. "I usually just kind of run across."

Crowell and other joggers, walkers and cyclists are at the heart of Sarasota's debate about whether to spend $19.5 million building three-lane roundabouts on U.S. 41 at Gulf Stream and Fruitville Road.
In addition to improving traffic flow, city engineers say the roundabouts -- small, slow-moving traffic circles -- will help achieve one of the city's major long-term goals: making the bayfront more pedestrian-friendly.

But engineering research is unclear about whether walkers, joggers and cyclists would benefit from multilane roundabouts.

Experts say roundabouts become more dangerous the more lanes they have, and some reports found that multilane circles can put bicyclists and visually impaired pedestrians at risk.
Per Garder, a University of Maine civil engineering professor who co-wrote a 2001 roundabouts study, believes the circles could work on U.S. 41. But he admits pedestrians might not benefit from the change.

"In my opinion, multilane roundabouts … would be as safe as a six-lane (highway) for pedestrians," Garder said. "It would not be an improvement for pedestrians."

In recent years, roundabouts have gained popularity among engineers, who praise their ability to reduce vehicle crashes while keeping traffic flowing smoothly. More than 200 have been constructed in the United States, according to a report by the independent federal U.S. Access Board.
Locally, Bradenton Beach has a roundabout, there's one on Hillview Street in Sarasota, and Englewood plans several.

Garder's study of 23 roundabouts, done with colleagues from Ryerson Polytechnic University and the Insurance Institute for Highway Safety, found that roundabouts can reduce fatal accidents by 90 percent and all accidents by 40 percent.

Yet in Clearwater Beach, the nation's largest roundabout had to be remodeled after it was blamed for hundreds of fender-benders.
Massachusetts officials recently tore up one accident-prone rotary and are planning to replace another with an overpass. New Jersey officials removed more than 30 traffic circles in the last 25 years.

Tom Cahir, assistant secretary in the Massachusetts executive office of transportation and construction, said modern roundabouts might work well in areas with low traffic volumes, but not in places expecting a population boom.

"If it's a long-term solution in a growth community, I think it needs to be looked at closely," he said.
Last year, an average of 31,500 cars a day crossed the intersection of Gulf Stream and U.S. 41, according to Florida's Department of Transportation.

Clearwater's multilane roundabout carries more than 50,000 cars and 6,000 pedestrians a day during peak season, said Clearwater public works administrator Mahshid Arasteh.

"It has been a good balance between moving traffic at a slow speed and pedestrian safety," Arasteh said.

Roundabout advocates bristle at the comparison to rotaries, saying New England's high speed traffic circles are larger and more dangerous than modern roundabouts.
Roundabouts are designed to keep drivers moving at about 15 mph to 20 mph. The roundabouts on U.S. 41 would have two continuous lanes plus right turn lanes at the entrance and exit points.

According to a Federal Highway Administration report, the "safety benefits of roundabouts have been found to generally carry over to pedestrians."

They help by slowing cars, reducing the distance walkers have to cross and lowering the frequency of collisions, experts say.
But unlike traffic signals, roundabouts never require drivers to stop. Yield signs slow cars as they enter, but pedestrians have to hope they obey the law and stop at crosswalks.

"Multilane roundabouts are less safe (than single lanes) for pedestrians and can be confusing," Garder said.

There have been relatively few studies, mostly conducted in Europe, about pedestrians and roundabouts, according to a federal agency that develops guidelines for complying with the Americans with Disabilities Act. Some say pedestrian crashes decrease with roundabouts; others say the crash rate remains the same.
The U.S. Access Board says little is known about the use of roundabouts by older pedestrians, children, pedestrians with disabilities and the blind.

Some local residents wonder how safe roundabouts will be in a community with a large population of older drivers and tourists who are not familiar with Sarasota's roads.

"I'm from Europe. I'm used to roundabouts," said Leroy Wilks who rides his bike downtown from his home on Golden Gate Point. "As long as people know how to use them, they make perfect sense."
But Bob Jamieson, a 62-year-old Massachusetts native who winters on Golden Gate Point, is less enthusiastic.

"My biggest concern is how people are going to approach those things," Jamieson said. "I'll tell you, in Massachusetts it's a game of chicken."

On St. Armands Circle -- which has multiple lanes, four entrance points and parking around the edges -- drivers are so busy looking for cars they don't see bicyclists, Damon Gannon said.

"It's a big intersection. It's pretty intimidating for bikes and pedestrians," said Gannon, a Mote Marine Laboratory scientist who bikes to work.
British and French studies have shown that bicycle crashes greatly increase when roundabouts replace traffic light intersections.

Sarasota city traffic manager Sam Freija said cyclists would be instructed to ride through the crosswalks instead of the roundabouts.

Freija said crosswalks would be built several car-lengths away from the entrance to the roundabouts. The crosswalks will be marked by flashing lights in the pavement and will include landscaped medians where pedestrians could stop in the middle of the four-lane road.
He's confident the circles will be safer for pedestrians and cyclists.

"We have not been to the nitty-gritty of the design," he said. "But eventually, if it gets approved that's something we have to do."
 
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