Im p r o v in g W o r k Z o n e S a fe ty :A lt e r n a t iv e s t o t e m p o r a r y c o n c r e t e b a r r ie r . Presentation Prepared by: The Water Barrier Manufacturers Association PO Box 1461 Salt Lake City UT 84110-1461 www.waterbarriers.org
P urpos e The purpose of this presentation is to educate transportation departments, consulting engineers, and others on the availability of new, cost effective, and safe alternatives to temporary concrete barrier for work zone traffic control.
Unfortunately, a result of infrastructureimprovements is work zone accidents,which take the lives of constructionworkers and motorists. Our nation needsto build better roads and bridges withoutsacrificing the safety of motorists andworkers.
D a ta According to the Bureau of Labor Statistics, there were 101 fatal occupational injuries at road construction sites in 2008 alone. In 2007, 831 workers and motorists were killed in highway work zones and more than 40,000 were injured. Eighty-five percent of those killed in work zones are drivers or their passengers.
A 2008 report by the Illinois Department ofTransportation recorded 31 fatalities inwork zones. Only two of the persons killedwere road construction workers, more than93% of fatal injuries where to drivers andtheir passengers.
Four out of five of the people who diein work zone crashes are motorists, nothighway workers according to theVirginia Department of Transportation.
The current mindset set of the safetycommunity is geared toward using “positiveprotection” to protect maintenance workersin roadway work zones.
As a result, concrete barrier has become thetemporary traffic control device most commonlyused in roadway work zones, even when thedata from work zone accident fatalitiesoverwhelmingly indicate that maintenanceworkers are in the minority of those killed inwork zone.
In fact, a recent survey of practices confirmedthat temporary concrete barrier is the optionmost frequently used by state transportationagencies.
Traffic engineers expect concrete barrier toimprove safety for the motorists and reasonablyprotect workers, but motorists can be subject toaverage forces of 9.55 g’s and as high as 23.5g’s (See table 1) when impacting at 25 degreeangles when traveling in standard size pickups.
The same vehicle when impacting water-filledbarrier systems at 25 degrees measuredaverage ride-down accelerations of 4.42 g’swith the highest measurement at 12.10 g’s,(See table 2).
T a b le 2Acceptance Code Test Level Material Deflection (meters) Deflection (feet) Acceleration (gs) B-196 3 plastic 2.74 8.99 10.90 B-125 3 plastic 4.78 15.68 8.40 B-97 3 plastic 4.28 14.04 10.00 B-48 3 plastic 6.90 22.64 8.70 B-34 3 plastic 3.40 11.15 12.10 Avg. Deflection 4.42 Average Gs 10.02
It is clear, when the crash test data is reviewed,that plastic water ballast devices create morepositive outcomes in the event of an accidentthan the use of traditional concrete barrier due tothe high G’s that motorists are subjected to whenimpacting concrete barrier.
S o W h y A r e W a t e r F ille d D e v ic e s n o t b e in g U t iliz e d ? If 85% of work zone accidents fatalities are drivers and their passengers, and water filled devices provide a higher degree of safety for the motorists passing through work zones, it would seem logical that water filled devices would be the traffic control device of choice.
Resistance to change slows industry-wide adoption of water ballast devices.There is an enduring familiarity withconcrete and a tendency to rely onconcrete barrier for every use, even whenit is not the safest or most appropriatedevice for the job.
There is an enduring familiarity withconcrete and a tendency to rely onconcrete barrier for every use, evenwhen it is not the safest or mostappropriate device for the job.
Because there is no requirement orincentive for change, engineers simplycontinue to specify temporary concretebarrier for all traffic control jobs, in spite ofthe innovation of safer and more effectivemechanisms.
In addition to the institutional factorscontributing to the lack of innovationlisted above, there is no funding forinnovative practices.
If better safety costs more money, it must be funded. FHWA’s rule on Temporary Traffic Control states: “… As a minimum, separate pay items shall be provided for major categories of traffic control devices, safety features, and work zone safety activities...” To comply with this rule states create itemized lists of work zone devices. Unfortunately, innovative devices are rarely if ever listed.
For example, the Longitudinal ChannelizingDevice, a traffic control device listed in theMUTCD for several years, is not listed in any ofthe itemized lists published by any State DOT’s.
It is im p o r t a n t t o r e c o g n iz et h a t u t iliz in g t h e f u ll a r r a yo f w o r k z o n e t r a f f icc o n t r o l d e v ic e s a v a ila b le ,a n d d e p lo y in g s u it a b let r a f f ic c o n t r o l d e v ic e s f o re a c h s p e c if ic jo b , c a np r e v e n t m a n y a c c id e n t a lin ju r ie s a n d d e a t h s in w o r kzone s .
T h e c o n t in u e d r e lia n c eo n te mp o ra ry c o nc re teb a r r ie r f o r e v e r y w o r kz o n e a p p lic a t io n ise x t r e m e ly h a z a r d o u st o t h e m o t o r in g p u b lic .