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<br /> intersection to convert the at one end while physically
<br /> intersection into two unconnected restricting through traffic.Studies
<br /> streets, each making a sharp turn. have shown cul-de-sacs or dead- !
<br /> Its primary purpose is to make end streets to be very effective in
<br />Diagonal Diverters travel through a neighborhood reducing traffic volumes.
<br />r,., circuitous, while not preventing Due to the need for adequate I
<br /> such travel. Used alone, the turning radius, retrofitting an
<br />~.~, divert°rs will affect only the two existing street can be very ~pensive.
<br />~'~, j,, ~ / specific streets involved. This On existing streets, it '{s often the case
<br />~; e~ q-4, aoolication is most effective irt ' that only an 18- to 20-foot turning I
<br />~'~".,.-'~ ,-I_ re~d~ucing traffic volumes if used as radius can be provided, whereas in
<br />
<br />~ ~, ~ vart of a planned system for the new subdivisions 35 feet (105 m) is
<br />~~ ~'~ ~ei~rhborhood that will discourage standard. The appropriate length of a
<br />~ ~'./~ through traffic. - ' "In street that can be dead-ended should i
<br /> Smith et al. (1980, 31) note that be determined by traffic volume and
<br />~--/~L-r~llall a system of devices, traffic on streets the number of houses on the street.
<br />r',~r~.~.'",~ ~ with divert°rs can be reduced from In ge~. eraL however,'.ctd.-d .e~_. ~ I
<br /> between 20 to 70 percent depen~g
<br /> streets longer than 500 feet when lots
<br />
<br />~ ~'~jl~. ~ Divert°rs are effective in re~:ucing are 50 feet wide, meaning there
<br /> would be approximately 20 houses I
<br />[~/'~ ~ traffic volumes, whereas speed is ........ ~4,~, oi~,ht to 10
<br />[z ~~(/~// teducedonlytnth.eimm.e..di...ate_ . onas~ee, s~-~-~,
<br />[~/"~ z~'/' /-,, vicinity of the diverter, wimm ar)o. ut vehtcle trips per day (NAHB !990,
<br />~~ ~/ ~ 200-300 feet. Studies done in SeaRle, 55). Streets longer than 500 feet tend
<br />
<br />~..//~ Berkeley, California, have shown a cul-de-sac because there are likely to
<br />~////--/d/~ significant r~luction in the number be increases in traffic speeds and
<br /> of accidents in the neighborhoods, mid-block tumar~uncls, a potential I
<br /> Usually, however, the actual number safety hazard. The number of
<br /> in each case was small oHginally properties on a longer street also
<br /> (Smith et aL 1980, 31). means an increase in the volume of .
<br /> In order to have diverters function trips on that street, again reducing I
<br /> safeIy and effectively, they should the safety factor that the cul-de-sac
<br /> incorporate the following features: should bring.
<br /> A cul-de-sac should be clearly
<br />~ · Visibility. Devices should have identified.by signs indicating that I
<br /> --d~:_~r [ painted curbs, rails, reflectors,
<br />[ ~ J directorial signs, street lights, the street ~s not a through street. In
<br />L ~ ~ and elevated landscaping, some cases, provision for passage
<br /> of emergen~ vekicles through the
<br />~ /r~ ° Delineation. Centerline pavement cul-de-sac i~y be'desirable.. I
<br />[~ ~ · ~ pavement buttons are hel~.d in bicyclists, and people with
<br />
<br /> evaluated and accommodated by
<br /> I · mergen , ve cle access, pro ,ion of oug sidewal
<br />~ ~~~~ I design of the diverter shotild and/or ramps.
<br />~"~' "~"~ ~"/~ I allow for passage of emergency The use of dead-end streets and I
<br />~ -'~/~,~_~J vehicles while restricting cul-de-sacs to reduce traffic
<br /> volumes is one of the most
<br /> automobile passage.
<br />r,,Y . pedes bicy e, and a bled e×p?ive least des able
<br />[/ ~ ~_~-~/~~ access. Sidewalks across the techmques employed for traffic I
<br /> calming due to issues of ·
<br />
<br /> accessibility for emergency
<br />I Street, CuI-de-sacs ve icles, uses, et . Caution shouldI
<br /> be employed in making use of this
<br />I '~~~/~!~' In some communities, traffictechnique.
<br />I ,'J~F'~~~ volumes in older residential areas
<br />L~~~~~a havebecome so problematic that
<br />Cul-cle-S~c Closures streets have been converted to dead- Sem~-diverters, Neck-downs, Chlcanes, I
<br /> ends or cul-de-sacs to prevent cut- Chokers, and Protected Parking
<br /> through traffic. A cul-de-sac is a A serni-diverter is a barrier to
<br /> complete barrier of a street at an traffic at the intersection of two
<br /> intersection or mid-block that streets in which one direction of the
<br /> leaves the block open to local traffic street is blocked, but traffic from
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