Georgia DOT : [benefits of installing medians]

Conclusions
In urban and suburban areas, raised medians: provide greater vehicle and pedestrian safety reduce left turn movements and turning conflicts and crashes by up to 55 perc ent provide landscaping and pedestrian refuge improve roadway level of service and reduce delays eliminate congestion associated with left tum conflicts and clearing crashes provide opportunity for landscaping result in minimal business impac ts and, in some cases, can result in improved business
Rai sed medians with " channelized" left turn lanes reduce intersection crashes, improve intersect ion traffic flow, access and signa l timing
Raised medians are most appropriat e for urban roads with traffic volumes of more than 24,000 vehicles per da y
In rural areas, dep ressed grass median s provide greater vehicle safety at high speeds, reduce crashes and improve likelihood of survival from crash
For more information, contact the Georgia Departm ent of Transportation Office of Planning at 404-656-5411 or the Office of Urban Design at (404) 656-5436 or visit our website at www.dot .state.ga .us
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The Georgia Department of Transportation www.dot.state.ga.us

THE BENEFITS OF INSTALLING MEDIANS
Improve Safety, Redu ce Crashes and Develop Community Pride
What are Medians?
Medians are one of the most effecti ve ways to separate two-way traffic on busy roadways. They eliminate or reduce turning conflicts and greatl y reduce crashes. Medians allow for better traffic flow and channel left tum movements to safer locations. Medians convert "two-way" traffic movement into two "one-way" movements. There are three types of medians utilized by the Georgia DOT: raised , flush and depressed grass median s.
Criteria for Raised Median Use
Urban arterials with current traffic volumes greater than 18,000 and future traffic volumes greater than 24,000 vehicles per day
High tum volumes
High crash rates
Large numbe r of driveways in area
Pedestrian crossings in area
Criteria for Use of Flush Median TwoWay Left-Turn Lanes (TWLTL)
Design speeds of 45 m.p.h. or less
Current traffic volumes of less than or equal to 18,000 and future traffic volumes less than 24,000 vehicles per day
Large number of commercial dri vewa ys
Large number of rear-end , sidesw ipe and truck/auto incidents
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Criteria for Depressed Median Use
Rural conditions High speeds, with need for additional space in
case of crashes
Conflicts Virtually Eliminated by Raised Medians
Left turns across heavy traffic Passing in center TWLTL
Acce lerating to merge in TW LTL Head-on crashes from opposi ng vehicles
Benefits of Raised Medians
Crash rates reduced up to 55 percent Reduced congestion Improved traffic flow (with permitted u-turns)
Provides landscaping and aesthetic opportunities Pro vides refuge for pedestrian crossi ngs
Improved community safety and pride Pro vides place for directional signs
Pedestrian Safety
Median s allow pedestrian s to gain refuge from traffic and avoid two -wa y left-tum mo vem ent s Vehiclepedestria n crash rates are fi ve times higher f or undivided fo ur-lane roads than for road s with raised median s in suburban areas
Pedestrian-vehicle accident rates were also higher at mid-block on undivided highways than on raised median sections

Landscaping and Community Revitalization
Raised, landscaped medians can significantly improve the aesthetics of an area
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Georgia DOT can install and pay for landscape materials if local govern ments agree to mainta in area
Wildflower plots in median s result in seaso nal co lor
Grass, wildflowers, low shrubs and ornamental trees greatly improve the appearance of a roadw ay
Garden club s and towns are often invo lved in promoting such areas
Mowing is reduced
Medians and Business Concerns
Some business owners believe their businesses will suffer because motorists will have difficulty getting to their estab lishme nts
Some consumers are creatures of habit and do not like to change their travel patterns to get to businesses
Studies have been conducted on the economic im pacts resulting from median installations and bu siness concerns in Texa s, Iowa and Kansas.

Texas Study
The Texas study analyzed the economic impacts of left-turn restrictions.
Business owners reported no change in traffic
Specialty retail, fast food establishments and restaurants reported increases in number of customers per day and gross sales
Adverse eco nomic impacts were discovered only during constructio n phase
After median installation some retailers experienced an increase in profits
Employment in the businesses and areas surrounding the median expe rienced a boost after co nstruct ion
Source: Eisele, ~v.L.. Frawley. WF. "A Methodology fo r Determining Economic impacts of Raised Medians: Data Analvsis on Additional Case Studies. " Research Report 3904-3, Texas Transportation Institute, Texas. October / 999.
Iowa Study
Thoroughfares with completed medians tend to have higher retail sa les than surrounding communities without median s
About 90-100 percent of surveyed motorists held favo rable attitudes towards median s
About 80 percent of businesses expressed no customer comp laints on ease of access to businesses after project com pletion
About 80 percent of business owners along these corridors stated that the level of sales were as high or higher with the installation of medians
Source: iowa State University, / 997
Kansas Study
The Kansas study assess ed the levels of eco nomic activity of 15 businesses before and after median installation. Of the 15 businesses, 14 were either upgraded or continu ed operations at the same level.
Source: Rees M., Orrick T., Marx R.; Police Power Regulation of Highway Access and Traffic Flow in the State of Kansas; 2000

Georgia, Florida and Michigan research studies all conclude raised medians reduce accidents, injuries and deaths, including that:

Divided highways are safer

Total crashes are reduced by up to 55 percent follo wing installation of a raised median

Traffic delays are decreased by 30 percent

Roadway capac ity is increase d by 30 percent

Rea r-en d , rates were

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and left-turn cras h median divided roads

than TW LTLs

All new and reconstructed arteria ls with more than 24,000 vehicles per day should have raised medians ( 1992)

Undivided highways have significantly higher cras h rates than those with raised medians and TWLTLs

A disproportionate amount of accidents involve left turn moveme nts

On arterials with more than 24,000 autos per day, reducing unrestr icted left turns is a key to reducing cras hes and delay

70 perce nt of total driveway cras hes are left turns entering and exiti ng driveways

Left tum bays reduced crashes 25 to 50 perce nt on four-lane roads and up to 75 percent at intersections
Source: Access Management Manual. Transportation Research Board
Benefits Include...

Fewer pedestrian and vehicle crashes

Reduced crash severity and incidents cleared faster

Reduced congestion and delay s
Installation of TWLTL's or flush medians to existing multi-lane roads results in...

35% reduction in total crashes

30% decrease in delay

30% increase in capacity