kind of crashes do not occur at roundabouts
Source: "Topeka News"
- The Topeka Capital Journal (08/23/2002)
SAY CIRCULAR THE BEST ROUTE
Source: "Topeka News"
- The Topeka Capital Journal (05/04/2001)
like direct routes when going from point
A to point B.
Perhaps that is
why some Shawnee County residents are a
bit concerned about a roundabout being
installed at S.W. 29th and Urish.
engineer Lynn Couch said he had received
six calls by Tuesday about the
construction of the roundabout.
Construction started in late April. He
said most callers were concerned with
drivers cutting through business's
parking lots to get to their destination,
rather than following detours.
roundabouts move traffic in a
counterclockwise circle. When drivers
approach a roundabout, they yield to
traffic coming from the left and enter
the roundabout by turning right.
roundabout is a circular
intersection that includes the
YIELD AT ENTRY
-- At roundabouts, the entering
traffic yields to circulating
traffic. This yield-at-entry rule
from locking up and allows free-flow
The splitter and center islands
of a roundabout deflect entering
traffic and reinforce the
FLARE -- The
entries often flare out from one
or two lanes to two or three
lanes at the yield line to
capacity to move traffic.
While the Kansas Department of Transportation has
put in two such roundabouts at the Interstate 70
and S.E. Rice Road interchange in Topeka, the
modern roundabouts are still new to the area and
the state as a whole.
"Kansas doesn't have many at
this point," said Eugene R. Russell, Kansas
State University transportation engineering
Russell, along with some of his
students, has been researching modern roundabouts
for about three years. He said modern roundabouts
have been growing in popularity.
"The bottom line is we
believe they are the safest, most effective way
to direct traffic," Russell said.
Modern roundabouts have worked in
Australia and Europe since the 1960s, KDOT senior
traffic engineer David Church said.
"It's taken a number of years
for the U.S. to start using modern roundabouts,"
Church and Russell said many
people confuse modern roundabouts with traffic
Russell said the central islands
of most modern roundabouts have an average
diameter of 20 to 30 feet. The diameters can
reach up to 100 feet. If the island is 200 to 300
feet in diameter and the roundabout has multiple
lanes of fast-moving traffic, it is considered a
Russell said Great Britain almost
gave up on roundabouts initially. The country
researched the issue and found that if the
roundabouts were smaller and lower speed limits
were enforced, the traffic pattern worked.
"It gets frustrating because
many people don't have the facts about modern
roundabouts," Russell said. "They base
things on what they hear about DuPont Circle in
Washington, D.C., or the traffic circle by the
Arc de Triomphe in France. DuPont Circle is
confusing. I don't disagree."
Learning by example
One Kansas intersection that has
seen a high number of injuries now relies on a
Hutchinson installed a roundabout
in fall 2000 after receiving a grant from KDOT
requiring one at a problematic location,
according to Stephen Williams, city civil
"We had 19 injury accidents
in a little more than a year at this
intersection," he said.
Williams said that in four months
with the roundabout, two accidents occurred, but
no one was injured.
"The safety that comes with a
roundabout far outweighs any cost," he said.
Roundabouts are considered a safe
way to flow traffic because they cause drivers to
Shawnee County public works
director Mike Sease said that if drivers obey the
rules at the S.W. 29th and Urish roundabout, cars
and trucks should move at about 20 mph.
Russell also said that because
traffic is constantly moving, not as much traffic
will back up as at a four-way stop.
When building a roundabout,
engineers have to make sure it can handle any
vehicle that may use it.
Couch said the S.W. 29th and Urish
roundabout is designed to handle semi-trucks
making drop-offs at the nearby Dillons and school
buses. He said the island is about 40 feet in
diameter and the road is 16 feet wide. An
additional 10 feet of concrete runup is being put
in to handle large trucks using the roundabout.
The S.W. 29th and Urish roundabout
was designed by Cook, Flatt & Strobel
Engineers, a local firm. President Darold Davis
said that after doing an initial study, his firm
recommended that the county install a traffic
signal at the intersection.
However, time and money also had
to be considered.
Sease said the traffic signal
project would have cost $1 million or more while
the roundabout project will cost about $160,000.
Dillons, Mission Township and the Sherwood
Improvement District are helping with the costs.
Sease said the combination of new development in
the area and the recent opening of Dillons
increased the urgency of the project.
The roundabout is expected to open
in about two months.
Despite some opposition, Russell
and Church said they believe roundabouts will
become commonplace in the United States.
"There's usually some
opposition at first, but after a roundabout is
installed, people flip-flop," he said.
"People like them because they're safe and
simple. It's really just a matter of giving
modern roundabouts a chance."
Church said KDOT will probably
build another roundabout in several years at the
intersection of US-75 highway and N.W. 46th.
Russell said he tries to keep
track of all of the roundabouts being built or in
use in the United States, but he expects there
will be too many to count someday.
"People weren't too sure
about traffic signals when those started going
up," he said. "But people learned how
to use them. I'm sure the same thing will happen
- Lawrence Journal-World, Wednesday April 18,
Local traffic planners should make
sure that the new traffic roundabout fad won't
pose serious problems for fire trucks traveling
to an emergency.
Concerns about how traffic
roundabouts affect fire trucks' ability to travel
around Lawrence deserve the serious attention of
Police cars en route to a recent
accident on Harvard Road several blocks east of
Wakarusa Drive reached their destination by
traveling through the roundabout intersection on
Monterery Way and then west on Harvard Road. A
fire truck en route from the station at 3708 W.
Sixth took a slightly longer route traveling to
Wakarusa Drive and then back east on Harvard, but
not through the roundabout.
Although fire officials said the
roundabout wasn't the only determining factor for
the route taken by the truck, they also say they
are working on a report about the effect of
roundabouts on emergency travel. The ability of
large fire trucks to get to their emergency
destinations is something that should concern all
That concern will increase along
with the number of roundabouts approved at various
locations in the city. One area of great concern
should be Louisiana Street south of the Kansas
Public Works Director George
Williams said the city has been careful not to
put roundabouts on "major routes." The
city apparently is working with the fire
department to determine major response routes
that won't involve roundabout intersections.
But looking at future plans for
Louisiana Street, it's difficult to see how fire
response routes to some parts of town would not
be impeded. Up to seven roundabouts are being
considered on Louisiana Street, including
locations at Louisiana's busy intersections with
19th Street and 27th Terrace.
Both 19th and Louisiana Streets
provide important access to KU and Lawrence High
School, as well as nearby residential areas.
South of 23rd Street, Louisiana is the only
through north-south street between Haskell Avenue
and Iowa Street. It is difficult to see how it
wouldn't be considered a "major route"
for all traffic, especially emergency vehicles.
It's not impossible for big fire
trucks to negotiate traffic roundabouts, but the
structures present special problem, especially
for large ladder trucks with a wide turning
radius. Trucks may have to jump curbs or travel
against the normal traffic flow to make the turns.
Hopefully, other drivers would have the sense not
to stop inside a roundabout when a fire truck
approaches, but even in the best of
circumstances, the presence of roundabouts
complicates travel for the large trucks.
Many Lawrence residents have doubts about the
advisability of so many traffic roundabouts on
Louisiana Street even for everyday traffic. An
awarencess of problems the structures pose for
fire trucks will olny magnify those concerns.
There may be a compormise that would reduce the
number of obstructions planned for Louisiana
Street, but here should be no compromise when it
comes to providing the fastest, safest possible
access for fire trucks to reach emergency
SAVE LIVES, STUDY FINDS
Engineering Lawrence Journal World Saturday,
March 31, 2001
Roundabouts, becoming more common
in America's road system, reduce deadly
automobile accidents at intersections by nearly
90 percent, researchers said.
Richard Retting, of the Insurance
Institute for Highway Safety, said drivers have
to get over their skepticism of the modernized
"Mistakes at roundabouts
result in fender-benders. Mistakes at stop signs
and traffic signals can be catastrophic,"
said Retting, an author of the study. "Thousands
of needless injuries could be prevented."
The study involved 24
intersections that were converted to roundabouts.
In roundabouts, drivers merge on a one-way road
built around a landscaped circle. Roundabouts,
unlike older circular intersections, don't have
There were 38 percent fewer
accidents at the roundabouts studied, the report
found. Wrecks with injuries fell by 76 percent
and accidents that caused deaths and very serious
injuries dropped 89 percent.
About 300 roundabouts have been
built in America in the past 10 years, including
two in Lawrence. "It's slowly catching on,"
said Mike Niederhauser, a transportaion engineer
for the state of Maryland. He said drivers
initially complained that while roundabouts were
popular in Europe, they wouldn't necessarily work
Retting and researchers from the
University of Maine and Ryerson Polytechnic
University in Toronto studied single and
multilane roundabouts in California, Colorado,
Florida, Kansas, Maine, Maryland, South Carolina
and Vermont. Four of the intersections previously
had traffic signals; 20 had stop signs.
Researchers found motorists
approach traditional intersections traveling
about 30 mph, compared to about half that at
roundabouts. The study said that there are about
700,000 accidents with injuries, causing $1.3
million damage, at intersections with traffic
lights and stop signs in America each year. About
half of all car crashes with injuries occur at
intersections, researchers said.
The design eliminates left turns,
a major source of accidents, and rear-end
collisions caused by drivers stopping suddenly at
yellow lights. Also eliminated are accidents
caused when a driver makes a right trurn into the
path of fast-moving traffic.
"The country has relied on
traffic signals and signs since the advent of the
automobile," Retting said. "If you have
an intersection you put up a stop sign, and if
it's too busy for that you put in a traffic
signal, and if it's too busy for a traffic signal
you put in an overpass."
Retting said traffic signals cost
about $150,000 at major intersections, while
roundabouts cost between $50,000 and $400,000.