SLIDE 1 2019 Bridge Design Conference 2/14/2019 1
MA MASH Im Imple plementation of
Beam Guar Guardrai ail and and Bri Bridge Railin Railing
Elizabeth Phillips & Katherine Smutzer INDOT Standards and Policy
What Do We Want you to Get From this Session?
What mi mist stakes es should should yo you av avoid wi with MGS MGS guar guardr drai ail sy systems?
If yo you need need to to mo modify an an MGS MGS guar guardr drai ail sy system, send send yo your recommen mmendation
in fo for re review, Desi DesignM gnManual nualInqui nquiries@ ries@indot. ndot.IN IN.gov
What do do we we ha have to to look look fo forward to to fo for MA MASH impl plemen ementati tion
bridge railin iling? g?
SLIDE 2 2019 Bridge Design Conference 2/14/2019 2
Let Letting ing Dates ates (W (Wit ith Latest atest Up Upda dates)
December 31, 31, 2017: 2017: St Standa andard W‐Beam Beam Guar Guardrail ail & Perm rmane anent Concr
Barrie Barriers
June 30, 30, 2018: 2018: Sing Single le‐Si Sided ded Ta Tangent Guar Guardr drail End nd Tr Treatments (End (End Te Terminals)
December 31, 31, 2018: 2018: Im Impa pact Attenu nuators, s, Cable Cable Barrie Barriers & Cable Cable Te Terminals
December 31, 31, 2019: 2019: Bridg Bridge rails ils, tempor
- rary work
- rk zon
- ne devic
ices*, tr trans ansitions, Cable Cable Barrie Barriers & Cable Cable Te Terminals, ot
her lon
gitudinal barrier ers (includes cludes Double‐ Si Sided ded (M (Med edia ian) End End Trea eatmen tments, ts, Fla Flared End End Tr Treatments, W‐Beam Beam Guar Guardr drail ail Tr Transition to to Concr Concrete Bri Bridge Rail Rail, W‐Beam Beam Gu Guar ardr drail ail wi with th Reduced duced Po Post Spac Spacing ing),ot ,other term rmina inals, s, sign sign suppo support rts, s, and and all ll other bre reakaway hard rdwa ware re * Tempor
ary work
ices manuf nufactur ctured ed before 12/ 12/31/19 31/19 tha that were success ccessfull lly crash test sted ed under under NCHRP CHRP 350 or MASH ASH 200 009 may con continue inue to be be used used th throughout ughout their their “norm normal al ser service ice life. e.” IND NDOT wi will ll determ rmin ine “nor normal service ice lif ife”.
Sunset Dates NCHRP 350/MASH 2009
June June 30, 30, 2018: 2018: Sing Single le‐Si Sided ded Ta Tangent Guar Guardr drail End nd Tr Treatments (End (End Te Terminals)
27 ¾” ¾” OS OS End End Trea eatm tmen ent is is no no lo long nger available ailable on
the Ap Approv
ed Mate Material al Li List (A (AML)
Don’t use use 27 27 ¾” ¾” OS OS End End Trea eatm tmen ent pa pay it item
Wher ere a Cur Curved ed W‐Beam Beam Gu Guar ardrail ail Conne Connector Sys System re require res an an OS OS End End Trea eatm tmen ent. t.
MGS Hei Height ht Tr Transition should should be be used used to to allo allow a 31” 31” OS OS End End Trea eatm tmen ent to to be be pla placed.
If sit site lim limit itations pr preven ent the the pla placemen ent of
both a MGS MGS Hei Height ht Tr Transition and and a 31” 31” OS OS End End Trea eatm tmen ent, t, send send in in an an inquir inquiry fo for yo your the the pr project.
Pr Provide the the fo following wi with th yo your inqu inquir iry: y:
Projec ect Des Des Num Number
Constru truction tion pla plans
Plan details ils sh should sh show th the st standar ndard gu guar ardrail ail sy system th that will will no not fit fit yo your lo location an and wh why
pproa
ch AAD AADT
Cras ash his history at at the the in intersection
Sunset Dates For OS End Treatments
SLIDE 3 2019 Bridge Design Conference 2/14/2019 3
Curved Guardrail System (Std Dwg. 601‐CWGS)
Curved guar guardrail consis
beam and and co cont ntrolled ed re releas leased ed te terminal al (CR (CRT) pos posts
Currently tly no no MASH MASH‐co comp mpliant equiv equivale lent
Design Opt Options
Transition MGS MGS to to W‐bea
Use MGS MGS Heig Height Tr Transition and and Cur Curved Gu Guar ardr drail ail Syste System Standar andard.
Where th ther ere is is lim limit ited ed space, space, it it ma may be be necessar necessary to to in install all NCHRP NCHRP 350 350 co compliant devi devices ces in in a quadr quadran ant th that re requi quires es cur curved ed w‐beam beam guar guardrail.
Coordi dina nati tion
with St Standa andards and and Policy licy Off Office is is re requir quired.
Update: There is currently an active NCHRP Report, NCHRP 15-53, that is working on a curve end treatment with a rail height of 31 inches. The completion date is set for December 2019.
The MGS MGS Tr Transition and and MGS MGS Lon Long Sp Span an requir quire th the use use of
12‐in. in. deep deep bloc blockouts. s.
Midwest Guardrail System (MGS) Reminders
MGS Transition
SLIDE 4 2019 Bridge Design Conference 2/14/2019 4
Each CRT Post has a 12” blockout Each CRT Post has a 12” blockout
The MGS MGS Tr Transition and and MGS MGS Lon Long Sp Span an requir quire th the use use of
12‐in. in. deep deep bloc blockouts. s.
Midwest Guardrail System (MGS) Reminders
- Min. Length of MGS Long Span, Type 1 or 2
MGS Long Span Pay Limits
MGS Long Span
FYI: The W-Beam Nested Guardrail System used two 8” blockouts, a total of 16” at each CRT post
Provi
ft of
bankment be behind hind th the back back of
Where lim limit itatio ions with within in th the pr project pr preven ent th the 2 ft ft of
embankm nkment fr from being being plac placed.
For Standar andard MGS MGS W‐Beam Beam Guar Guardrail (6’ (6’‐3” 3” pos post sp spacing) an an inqu nquiry iry is is not not requi quired, d, a le level tw two desig design exc except ption sh should be be fil filed with with th the pr project. t.
For all all oth
MGS W‐Bea Beam Guar Guardr drail ail Syst System ems, s, a pr proje
ecific inqui quiry will will be be requi quired.
The appr approved inqu nquiry iry sh should be be fil filed with with a le level tw two desig design ex except ption.
Midwest Guardrail System (MGS) Reminders
Example MGS Long Span: Make sure to take into account the 12 inch blockout and 2 ft embankment width behind the post when laying out your typical section
SLIDE 5 2019 Bridge Design Conference 2/14/2019 5
System Modific Modifications tions
Do not not mod modify th the sy syste stems, e. e.g.
remove move a pos post, modi modify a pos post, reduce duce th the em
If you you ha have a pr project th that you you feel eel need needs special special cons consider ideratio ion, sen send in in an an inquiry
If an an app approved modi modifi fica cati tion
is re recommen commended, th that re recom commendation
shou
ld be be file filed with with a le level tw two design design ex except ption.
MGS Lo Long Sp Span an Pay Pay Li Limits ts
The pa pay lim limit its ar are fr from ou
CRT pos post to to ou
CRT pos post.
For th the sy syste stem to to pr preform pr properly ly a mi minim nimum len length of
MGS w‐beam beam guar guardr drail ail sh shou
ld be be pr provide ided on
the appr pproach
and depa departure end ends of
the ou
CRT pos posts.
The mi minim nimum len length can can include clude MG MGS w‐beam beam guar guardr drail, ail, a tr transition, an an OS OS end end trea eatm tmen ent, t, or
cable term terminal inal an anch chor.
Midwest Guardrail System (MGS) Common Mistakes
FYI: Do not Flare an OS End Treatment more than 25:1
MGS Long Span Pay Items
- Pay Item unit “Each” includes
distance between outmost CRT posts
- Additional length required
each end.
Pa Pay It Item em Lim Limit, Ea Each, fo for Ty Type 1, 1, Be Between Ou Outmost
CRT Po Posts = 43’ 43’‐9” 9” A A
A This length is required on the approach and departure ends of the
- utermost CRT posts. It may
contain, MGS W-Beam Guardrail, Transition, End Treatment, or Cable Terminal Anchor. These items are paid for separately from the MGS, Long Span, Type 1. CRT Posts w/ 12” Blockouts CRT Posts w/ 12” Blockouts
SLIDE 6 2019 Bridge Design Conference 2/14/2019 6
MGS Long Span Pay Items
- Pay Item unit “Each” includes
distance between outmost CRT posts
- Additional length required
each end.
Pa Pay It Item em Lim Limit, Ea Each, fo for Ty Type 2, 2, Be Between Ou Outmost
CRT Po Posts = 50’ 50’‐0” 0” A A
A This length is required upstream and downstream of the outermost CRT post. It may contain, MGS W- Beam Guardrail, MGS Transition, MGS End Treatment, or Terminal End Anchor. These items are paid for separately from the MGS, Long Span, Type 2. CRT Posts w/ 12” Blockouts CRT Posts w/ 12” Blockouts
Simila lar to to mos most code code ch changes, th the im implementation to to MASH MASH as as th the cu curr rrent st standar dard fo for cr crash tes testing ing ro roadside hard rdwa ware re doe does not not requir quire th that all all ex existing guar guardrail be be replace placed immedi mmediatel ely.
In addit ddition
to th the sun sunset da dates fo for new new ins installa allatio tions and and fu full replace placemen ents ts, th the FH FHWA‐AASHT AASHTO Im Implementation Plan Plan ur urged St State DO DOTs to to es establish blish a pr proc
to replace place ex existing high highway har hardware. Th The fo focus being being on
syste stems th that ha have not not been been succes successfully ully tes tested to to NC NCHRP Re Report 350 350 or
later crit iteria. eria.
INDOT en encourages looking
for opportunities pportunities to to upgr upgrade de.
Instead of
asking “d “do I ha have to to upgr upgrade? de?” consider consider “is “is th this th the
pportunity to to upgr upgrade?” or
“is it it co cost eff effect ctive?” e?”
Again, ain, if if yo you ha have a ques questio tion, as ask.
When to Upgrade Guardrail and End Treatments
SLIDE 7 2019 Bridge Design Conference 2/14/2019 7
Items to to re review ew when when consi considering ering guar guardr drail up upgrade include: clude:
What sys system is is cu currently in in pla place? Is the system NCHRP‐350 TL‐3 Tested, does it match Standard Drawing Series E601‐WBGA? If the blockouts are steel, it is not NCHRP‐350 TL‐3 tested.
Scop
the pr
- project. 4R, 3R, or Preventative Maintenance (PM)?
- Ti
Time fr frame of
future wo
- work. If your project is a short term band‐aid and the
entire roadway is being reconstructed 5 years from now, the second project is likely the better opportunity for upgrading. If the guardrail only serves to protect the bridge ends, then the concrete overlay project (even though PM) may be the right opportunity to upgrade.
Functional cla classifi fication of
the ro roadwa
- way. Interstates should have a higher
priority for upgrading, regardless of project scope.
Crash ash his
- history. Frequent crash locations may benefit (in safety and
maintenance) from upgrading.
Traffic Coun Counts.
- ts. High traffic volumes are typically associated with higher
risk.
When to Upgrade Guardrail and End Treatments When to Upgrade Guardrail and End Treatments
Wher Where to to st start wh when con conside idering ing a guar guardr drail ail upgr upgraded to to MASH MASH‐ co complian liant hard rdwa ware re :
Project ect Sc Scope
Roadway way Fun Functional Class Classific ficatio tion
Test Le Level of
the Exis Existin ting Guar Guardr drail, ail, (I (IDM Se Sect ctio ion 49 49‐5.02) 5.02)
Perc rcent of
Existin ting Gu Guar ardrail being being Replace placed or
Reset
SLIDE 8
2019 Bridge Design Conference 2/14/2019 8
When to Upgrade Guardrail and End Treatments
Superscript numbers will require the designer to check the existing rail height, coordinate with the District to determine the existing condition, etc.
When to Upgrade Guardrail and End Treatments
Superscript numbers will require the designer to check the existing guardrail to be replaced, coordinate with the District to determine the existing condition, etc.
SLIDE 9
2019 Bridge Design Conference 2/14/2019 9
When to Upgrade Guardrail and End Treatments When to Upgrade Guardrail and End Treatments
C=0 for this Sample.
SLIDE 10 2019 Bridge Design Conference 2/14/2019 10
When to Upgrade Guardrail and End Treatments When to Upgrade Guardrail and End Treatments
Bridg idge Pr Prev even entati tive ve Ma Mainte tena nance nce Project jects (I (IDM 412 412‐3. 3.01(05)) 01(05))
Upgrade ade ex existing guar guardrail whe when found und to to be be cos cost eff effect ctive, e, e. e.g. g. th the co concrete te bridg bridge railing iling tr transiti tion is is being being re replace aced an and th the pos posts fo for th the ex existing tr transition need needs to to be be re removed moved; replace place th the gu guar ardrail tr transiti tion.
Bridg idge Rehabilit habilitatio ion Pr Projects ects (I (IDM 412 412‐3.01(05)) 3.01(05))
All ex existing ro roadside sa safety it items, inclu includin ing but but not not lim limit ited to to guar guardrail, ail, tr transitions, and and end end trea eatm tments ts sh shou
ld be be upgr upgraded ed to to cu curr rrent st standar dards. s.
Current Standards: We would consider retaining existing NCHRP-350 compliant guardrail. We would reply on the District to inspect the existing guardrail for remaining service life and current condition. Send in an inquiry.
SLIDE 11 2019 Bridge Design Conference 2/14/2019 11
When to Upgrade Guardrail and End Treatments
Bridg idge Pr Prev even entati tive ve Ma Mainte tena nance nce Pr Project ects, ID IDM 412 412‐3.01(05) 3.01(05)
Roadside sa safety fe features sh shou
ld be be upgr upgrade to to cu current st standar andard wh when pr proved to to be be cos cost eff effect ctive as as part part of
preven entativ tive main maintenance tenance pr proj
t.
If th the guar guardrail wo work is is ver very lim limit ited and and does does not not requir quire pos posts to to be be re remov moved, th the en end trea eatm tmen ents ts ma may re remai main in in plac place.
Bridg idge Rehabilit habilitatio ion Pr Projects ects, IDM IDM 412 412‐3. 3.01(05) 01(05)
All ex existing ro roadside sa safety it items including cluding but but not not lim limit ited to to guar guardr drail, ail, tran ansition sitions, s, an and end end trea eatm tmen ents sh shou
ld be be upgr upgrade ded to to cu curr rrent st standar dards. s.
There ma may be be cases cases th that allo allow a NC NCHRP‐350 350 TL TL‐3 tes tested ed en end trea eatm tmen ent to to re remai main in in plac place.
Ask th the ques questio tion.
Current Standards: We would consider retaining existing NCHRP-350 compliant guardrail. We would reply on the District to inspect the existing end treatment for remaining service life and current condition. Send in an inquiry.
Guardrail Recommendations Given in 2018 The The follo llowin ing slid slides will ill sh show som some gua guardrail re reco commen mmendation
that our
fice gav gave this this year year. The These re reco commen mmendation
were re a pr product
subm submit itted inquiry nquiry.
SLIDE 12 2019 Bridge Design Conference 2/14/2019 12
Example of When Guardrail May Not be Needed Example of When Guardrail May Not be Needed
The existing culvert had already been extended to the one side. The runout area is very flat. Why introduce guardrail in front
SLIDE 13 2019 Bridge Design Conference 2/14/2019 13
Example of When Guardrail May Not be Needed
Rang Range of
eatm tmen ents ts ID IDM Chap Chapter 46 46 se sectio ion 49 49‐3. 3.01(01) 01)
Remove ve or
redesign so so th that it it ca can be be sa safely tr traverse sed
Relocat cate outs
the cle clear zo zone to to a po poin int wher where it it is is le less li likely to to be be hit hit
Make br breakaway to to re reduce im impact se severity
Shield ld wi with th a tr traffi fic barrie rrier or
impact atte ttenuator
Delineate if if th the ab above tr treatment ar are no not practic actical
Placement of a Barrier, #4
Example of When Guardrail May Not be Needed
It Items to to Conside Consider fo for Main Maintaining aining th the Ext Extended Str Structure with without Guar ardr drail ail Pr Protect ection:
What need needs to to be be pr prot
this pr proj
t? (C (Concentrate on
the sid side with without ex existing guar guardr drail) ail)
The cu culvert end end does does not not need need to to be be shielded shielded bec because use:
The cu culvert can can da daylig ylight ou
ide of
the Clear Clear Zo Zone ne
The gr grad ading ing prio prior to to, over
and pas past th the cu culvert ar are rela lativ tively ly fl flat (10:1 10:1 or
ss) or
the dit ditch is is tr
The gr grading ading pr provides ides ro room fo for re recov covery.
The cr crash his history does does not not lead lead th the design designer er to to pr protect th the cul culvert end end ou
tsid ide of
the cle clear zo zone.
SLIDE 14 2019 Bridge Design Conference 2/14/2019 14
Example of When Guardrail May Not be Needed
It Items to to Conside Consider fo for Main Maintaining aining th the Ext Extended Str Structure with without Guar ardr drail ail Pr Protect ection
(Cont’):
What need needs to to be be pr prot
this pr proj
t? (C (Concentrate on
the sid side with without ex existing guar guardr drail) ail)
The ut utility ility pole pole is is insid inside th the Clear Clear Zo Zone ne but but does does not not need need to to be be shielded shielded bec becaus use: e:
The ut utility ility pole pole is is in in a lon long line line of
utility poles poles th that par parallel llel th the ro roadwa way unshielded unshielded by by a barrie barrier.
The ut utility ility pole pole adja adjacent th the cul culvert is is not not cl closer to to th the ro roadwa way th than th the oth
poles par paralle lleling ing th the ro road.
The ut utility ility pole pole does does not not app appear to to ha have been been st struck ruck in in th the pas past. Reco comme mmendation wo woul uld be be to to ex extend th the cul culvert end end out
past th the clea clear zo zone, keep eepin ing th the appr approxim imate ex existing side side slop slope fo for re recove covery, and and not not place place guar guardr drail ail on
that side side of
the ro roadwa
Adding a run run of
gu guar ardrail ma may be be mor more of
hazard th than th the utility utility pole. pole.
Visually Consistent Corridor
If If a st structur cture is is ex extended be beyond nd th the cl clear zo zone or
slightly ly fa farther, keep eep a vis visual co consiste tency ncy to to bes best delinea delineate th the ro roadwa way. The extended aggregate shoulder was viewed as being part of the roadway.
SLIDE 15 2019 Bridge Design Conference 2/14/2019 15
Visually Consistent Corridor
If If a st structur cture is is ex extended be beyond nd th the cl clear zo zone or
slightly ly fa farther, to to elim elimina inate guar guardr drail, ail, keep eep vis visual co consiste tency
Visual al consis consistency ncy is is th the bes best wa way to to delinea delineate th the ro roadwa way.
Adding the grass and object markers better delineates where the driver should proceed. In addition, not visible in the picture, a rumble strip was added for further delineation.
Visually Consistent Corridor
Added grass visually directs the driver toward the roadway.
SLIDE 16 2019 Bridge Design Conference 2/14/2019 16
Do Not Place Posts in Structure Backfill Type 5
Som Some tim times a pr proj
may ca call ll fo for st structur cture back backfill fill ty type 5, 5, if if your your gu guar ardrail pos posts fa fall with within in th the lim limits its of
the st structur cture back backfill ll ty type 5 a spe specia ial de detail ail will will be be needed.
To allo allow th the guar guardrail pos posts to to ro rotate tate.
Roadside Design Guide, 5.6.7.1: A special detail is need to allow the posts to rotate in their embedment such that vehicle impact loads are distributed through the post into the embedment material prior to the post breaking prematurely.
Do Not Place Posts in Structure Backfill Type 5
- The location of the Modified
Posts is shown in the plans
- A detail of the Leave-Out Tubes
is detailed in the plans
contract to describe the construction requirement
SLIDE 17
2019 Bridge Design Conference 2/14/2019 17
Do Not Place Posts in Structure Backfill Type 5
Draft USP
Do Not Place Posts in Structure Backfill Type 5
The previous detail was modified from the design recommendation for posts to be placed in rock, see Roadside Design Guide Figure 5- 51b. Therefore where guardrail will be located in a rock area a similar detail will need to be created.
SLIDE 18 2019 Bridge Design Conference 2/14/2019 18
Do Not Place Posts in HMA or Concrete
Po Post shou should ld not not be be enc encased in in HM HMA or
concr ncrete pa
Simila ilar to to requi required gua guardrail pl placemen ent in in th the ar area of
struct ctur ure back backfill fill typ type 5 or
rock ck, a lea leave‐out
detail il and and th the lea leave‐out
locations shou should ld be be incl cluded uded in in th the pl plan ans.
The lea leave‐out
detail il fo for HM HMA and and co concr ncrete pa pavement is is not not nea nearly ly as as det detailed iled, it it is is basic basically lly a hole hole in in th the HM HMA
Concrete, back backfilled filled with with Stru Structure Back Backfill fill Ty Type 4. 4. Stru Structure Back Backfill fill Ty Type 4 is is remov moval and and has has a com compressiv ssive st stre reng ngth of
app approxim imately 120 120 ps psi.
Roadside Design Guide, 5.6.7.2 and Figure 5-52b
When to Use a Cable Terminal Anchor System
cable ter terminal al anch anchor sy syste stem is is mean meant to to be be used used on
the outg
end alon along a di divi vided hi high ghway (a (a gua guardrail end end th that is is not not ex expos posed to to onc
traffic)
cable ter terminal al anch anchor sy syste stem ma may not not be be sub substitu tituted with with 25 25 ft ft of
Beam am or
MGS MGS W‐Beam Beam guar ardrail ail
Wher ere ca cable te term rminal al anch anchors ar are pl placed aced, co consi nsider er fla flaring th the ra rail at at 25:1 25:1 but but no no mo more th than 15:1 15:1 aw away fr from th the ro roadw adway
If yo you ha have a lo location th that requi requires spe specia ial consid ideratio ion, yo you shou should ld sub submit it an an in inquiry
SLIDE 19 2019 Bridge Design Conference 2/14/2019 19
When to Use a Cable Terminal Anchor System
Example of
location th that requi required spe specia ial consid ideratio ion
This was a resurface project, no right-of-way acquisition, and existing right-of-way was not much past the EOP. The crash history, existing guardrail condition, and favorable geometrics were considerations. The recommendation was to provided two flared cable terminal ends, to match the existing condition and improve the performance of the existing guardrail by adding tension in the guardrail run upstream and downstream
- f the driveway. The flare was not to exceed 25:1 for this
- situation. Documented as Level 2 Design Exception.
Evaluate the Existing Guardrail Types
Example of
location th that co contai ains ns multip multiple le typ types of
guardrail
Large gaps of the Non-NCHRP- 350 with rubrail had been replaced, this may be an indication that these runs of guardrail have exceeded their service life.
- Ex. guardrail, 4 different types, mixture of really old and brand new.
SLIDE 20 2019 Bridge Design Conference 2/14/2019 20
Evaluate the Existing Guardrail Types
Example of
location th that co contai ains ns multip multiple le typ types of
guardrail
Project Information: Bridge Preventative Maintenance Project (overlay and replacing the bridge approaches)
- Interstate
- Speed Limit 55 mph
- Route in Non-NHS
- Next work to be completed on these bridges may be preventative maintenance.
- There are four different types of W-Beam Guardrail within close proximity of the
bridges in this preventative maintenance project.
NCHRP-350 wood blockouts Non-NCHRP-350 Steel blockouts with rubrail Example of Existing Guardrail
Evaluate the Existing Guardrail Types
Example of
location th that co contai ains ns multip multiple le typ types of
guardrail
Recommendation:
New 350 (blue) and older 350 (green) guardrail to remain in place.
steel blockout with and without rubrail (yellow and orange) with MGS systems adjacent the bridges in the project. These types of projects can be reviewed on a case-by-case
- bases. Do not make assumptions, ask the question.
SLIDE 21 2019 Bridge Design Conference 2/14/2019 21
Evaluate the Existing Guardrail Types
Example of
location th that co contai ains ns multip multiple le typ types of
guardrail
Evaluate the Ex. Guardrail Types, Condition, LON
Example of
location th that ma may requir required a re revie view of
the co condi ndition
the ex existing ng guar ardrail ail and and th the len length of
need (L (LON).
Project Information: Bridge Rehabilitation Project (overlay and replacing the bridge railing and coping)
- Mainline: AADT ~600 VDP
- Side Roads: AADT ~ 100 VPD
- Mainline: Speed Limit 55 mph
- Side Roads: Stop Condition
- Route in Non-NHS
- W-Beam Guardrail Placed in 1977
- Mainline Shoulder Width 10 ft
- Mainline Side Slopes 6:1 off Shoulder with in Clear Zone,
even behind Guardrail.
SLIDE 22 2019 Bridge Design Conference 2/14/2019 22
Guardrail Condition and LON Need to be Reviewed
Example of
location th that ma may requir required a re revie view of
the co condi ndition
the ex existing ng guar ardrail ail and and th the len length of
need (L (LON).
This project location has a lot of guardrail that is adjacent 10 ft paved shoulder and shallow side slopes that appear to lead to wide open fields. Radius of the mainline curve is 1400 ft.
Guardrail Condition and LON Need to be Reviewed
Gu Guar ardrail ail Re Reco comme mmendation: Minimu mum: m:
- The district must determined that the existing w‐beam guardrail and existing cable terminal
anchors are in good condition and can remain in place.
- Check the crash history
- Check the maintenance history
- All the existing aluminum guardrail must be removed and replaced with MGS transition and
MGS w‐beam guardrail (as needed), and MGS height transition.
- The designer should coordinate with the county to determine the need for replacement
and review of the guardrail along the country side roads.
Desir Desirable ble:
- Check all the LON calculations along the mainline to see if the guardrail lengths can be
reduced.
- Upgrade all the guardrail and end treatments along the mainline to current standards (in
accordance with the new LON calculations).
- All the lines of sight should be checked through the project, intersection sight distance,
passing sight distance, and stopping sight distance. It appears that through the project area the mainline is marked as a no passing zone.
SLIDE 23 2019 Bridge Design Conference 2/14/2019 23
Guardrail Condition and LON Need to be Reviewed
Gu Guar ardrail ail Re Reco comme mmendation: Minimu mum: m:
Some of the reasons that could be noted in the file for retaining the existing w‐beam guardrail and existing end treatments could include, but are not limited to:
- Upon a site visit, the district determined that the existing w‐beam guardrail and existing
cable terminal anchors are in good condition. (This should be confirmed by district maintenance or other district office that reviews guardrail conditions)
- The existing w‐beam guardrail along the mainline does have rubrail, as this does not
increase the test level it can reduce wheel snag on the posts.
- The accident history in the area of the project is low. (This should be confirmed by the
designer or project manager)
- The wide shoulders along the mainline, 10 ft, provides recovery room for an errant driver.
- The existing cable terminal anchors are flared away from the roadway. This may prevent a
head on collision with the anchor. Sid Side no note: A head‐on collision with a cable terminal anchor could spear a car. Don’t jump to a conclusion based on the AADT alone.
Guardrail Condition and LON Need to be Reviewed
Gu Guar ardrail ail Re Reco comme mmendation: De Desirable:
Some of the reasons that could be noted in the file for replacing all the guardrail:
- Reducing the length of guardrail may be eliminating a roadside hazard.
- The existing guardrail has been found to be deficient per the districts review.
- The next work to be completed on at this bridge is an overlay, this is preventative
maintenance and will not required guardrail replacement. This means the existing guardrail may remain for another 20 to 30 years.
- The existing guardrail end treatments are not crash worthy.
SLIDE 24 2019 Bridge Design Conference 2/14/2019 24
Example of When Guardrail May Remain In Place
Brid Bridge pr projec
that falls lls with within in th the lim limits of
road pr project ect Gen General ru rule of
umb:
Use th the pr projec
that calls lls fo for th the mo more st stringe ngent guar ardrail ail replacem replacemen ent. t.
Examples
If th the br brid idge wo work is is pr preven entative ma maintenance nance and and falls lls with within in a ro road rec recons nstruct uction
project (3R (3R), th the gua guardrail alon along th the ro roadway and and on
the br brid idge app approach ches shou should ld be be upgr upgraded to to cu current standar standards. s.
If th the br brid idge wo work is is reh rehabilit ilitatio ion or
replacemen ent and and falls lls with within in a ro road pr preven entative ma maintenance nance resurf resurface ace pr projec
t, th the gua guardrail on
the br brid idge app approaches shou should ld be be upgr upgraded to to cu current standa standards.
If th there is is an any
guardrail alon along th the ro roadway bei being resurf resurfaced ed (th (that is is not not on
the br brid idge app approach ch) th that guar ardrail ail shou should ld be be ev evalua aluated as as describ described fo for a ro road ad prev even enta tative mai maintenance nance re resurf surface ace pr projec
t, i.e i.e. che check th the to top ra rail hei height, ask asked th the di distric rict to to in insp spect th the ex existing ng guar guardrail, il, etc. etc.
- However like all rules of thumb there is normally a, “However”
Example of When Guardrail May Remain In Place
We We had had a gua guardrail in inquiry fo for a br brid idge reh rehabilit ilitatio ion pr project ect th that all all th the ex existing ng guar ardrail ail and and end end trea eatm tmen ents ts had had been been upgr upgraded to to NC NCHRP 350 350 bet betwee een 2010 2010 and and 2012 2012.
SLIDE 25 2019 Bridge Design Conference 2/14/2019 25
Example of When Guardrail May Remain In Place
Af After fu furt rther re review we we reco commen mmended th that th the ex existing ng guar ardrail ail and and end end trea eatm tmen ents ts rem remain in in in pl place with with th the follo llowing co condi nditions
and fo for th the follo llowing rea reasons.
Condi nditions:
The Dis District rict had had to to app approve th the reco commen mmendation
The Dis District had had to to fiel field ve verify th the guar ardrail ail ra rail hei height wa was a mi minim nimum of
27 ¾” ¾”
District certif certified ied in insp spector had had to to in insp spect th the end end trea eatm tmen ents ts to to det determ rmin ine th they we were re st still in in good good co condi nditi tion
Re Reasons:
The ex existing ng guar ardrail ail is is NCH NCHRP‐350 350 TL TL‐3 te test sted.
The w‐bea beam sy syste stem, with with ste steel pos posts and and wo wood/
posite te bl bloc
s, mar margin inally ally passed passed MA MASH SH TL TL‐3 cr crit iteria ia
The ex existing ng guar ardrail ail and and ex existing ng end end trea eatm tmen ents ts ar are only
to 8 ye year ars old
they shou should ld be be le left ft to to co compl mplete th their ser servic ice lif life, si similar ilar to to oth
existing ng NC NCHRP‐350 350 sy syste stems.
Moral of the story, if you think it may be able to stay, ask the question. The worst that can happen is we say, no.
When and Where to Upgrade Guardrail
Ex Extra Not Notes:
RSP 706 706‐B‐140d, 140d, TS TS‐1 Brid Bridge Railin Railing with with TG TGS‐1 Tr Transition, ma may ONL ONLY be be used used on
non non‐NHS NHS LP LPA co collect ctor
local ro roadways.
Current RS RSP det details a TG TGS‐1 Tr Transition th that co connect nnects in into w‐bea beam guar ardrail. ail.
Coming soon, soon, th the RS RSP det details ils will will be be upda updated to to incl clude ude a TG TGS‐1 Tr Transition th that connects connects in into MGS MGS w‐beam beam gua guardrail. ail.
SLIDE 26 2019 Bridge Design Conference 2/14/2019 26
When and Where to Upgrade Guardrail
Ex Extra Not Notes:
Wher ere ex existing ng guar ardrail ail is is bei being replaced, replaced, be be co consi
If one
side of
the ro roadw adway is is 50% 50% or
greater and and th the oth
is only
40%; Re Replace all all th the gua guardrail with with MA MASH SH‐Complian liant MGS MGS W‐Beam Beam on
both side sides of
the ro roadw adway.
Wher ere standar standard gua guardrail will will not not fit fit yo your specific specific guar ardrail ail loc location, send send th the follo llowing in information to to DesignM gnManual nualInqui nquiri ries@ es@indot ndot.IN. IN.gov fo for an an alt alternate guar ardrail ail reco commen mmendation:
Project De Des Nu Number
nstruct uction
plan ans
Plan an det details ils shou should ld sho show th the standar standard gua guardrail sy syste stem th that will will not not fit fit yo your loc location
Plan an det detail il shou should ld sho show a pr prop
ed solu solutio tion, if if th the desig designer er ca can not not pr prop
solution, sta state so so in in th the reques request
Snap shot shot of
project lo location
MGS Weak Post Bridge Rail TL‐2 or TL‐3
https://mwrsf.unl.edu/researchhub/files/Report53/mgsbr1aos3.wmv https://mwrsf.unl.edu/researchhub/files/Report53/mgsbr1aos4.wmv https://mwrsf.unl.edu/researchhub/files/Report53/mgsbr1jvc1.wmv These are links to the crash test videos for Crash Test TRP-03-226- 10 preformed by Midwest Roadside Safety
will review these rail types for incorporation into the standards.
SLIDE 27
2019 Bridge Design Conference 2/14/2019 27
MGS Weak Post Bridge Rail TL‐2 or TL‐3 MGS Weak Post Bridge Rail TL‐2 or TL‐3
SLIDE 28 2019 Bridge Design Conference 2/14/2019 28
MGS Weak Post Bridge Rail TL‐2 or TL‐3
MA MASH Im Imple plementation of
Bridge Railin Railing
SLIDE 29 2019 Bridge Design Conference 2/14/2019 29
STATE ROUTES
Railing Designation MASH Test Level Nominal Height Description FT TL‐5 45” Concrete F‐shape TF‐2 TL‐5 50” 2 steel tubes with steel posts on concrete parapet FC TL‐3 33” Concrete F‐shape PS‐1** TL‐4* 42” 2 steel tubes with steel posts on 24” concrete parapet, sidewalk mounted PF‐1** TL‐4* 42” 2 steel tubes with steel posts on 24” concrete parapet, deck mounted
INDOT Standard Bridge Railing ‐ 2019
* INDOT will designate as a TL‐3 railing ** Modification to steel tubes
LOCAL AGENCY, NON‐NHS ROUTES ONLY
Railing Designation NCHRP 350 Test Level Nominal Height Description TX TL‐2 42” Vertical concrete parapet with windowed openings TS‐1 TL‐2 33” Side‐mounted thrie beam guardrail.
INDOT Standard Bridge Railing ‐ 2019
- Local agencies are encouraged to install MASH‐compliant bridge
railing.
- LPA bridges on non‐NHS routes may continue to install NCHRP
350‐compliant bridge railing at their discretion.
SLIDE 30 2019 Bridge Design Conference 2/14/2019 30
Bridge Railing Evaluation Criteria
Q & A Research/Crash Tests In‐Service Performance and Frequency of Use
Bridge Railing – Evaluation Criteria
Impact forces based on test level Strength
- All factors of the barrier that prevent the vehicle from penetrating the barrier
Tall enough? Stability
- All characteristics of the barrier, such as height, shape, and stiffness, that affect
vehicle stability
- TL‐3 27in. 29 in., TL‐4 32 in. 36 in., TL‐5 42 in. 42 in. (unchanged)
Will it snag? Geometry
- All geometric features that affect occupant risk, such as post setback, clear
- pening between longitudinal rail elements, and available vertical contact
surface area.
- Post setback criteria – LRFD Appendix A
- Asperity Depth and Width guidance – NCHRP Rpt 554 Aesthetic Concrete
Barrier Design
SLIDE 31 2019 Bridge Design Conference 2/14/2019 31
- Bridges with speeds of 45 mph and below must have railings that
meet TL‐2 criteria or greater.
- Bridges on the NHS must have railings that meet TL‐3 or greater,
regardless of design speed.
TL‐2
- Bridges with speeds of 50 mph and above must have railings that
meet TL‐3 criteria or greater.
- A TL‐5 or greater railing should be considered if any of the following
criteria are met
- Sustained longitudinal grade greater than 5%
- Horizontal curve radius less than 1,500 ft.
- High hazard environment below the bridge, such as a densely
populated area.
- In‐service performance of existing TL‐3 rail inadequate
TL‐3
- Bridges carrying mainline Interstate routes or system interchange
ramps
TL‐5
Test Level Selection
- Bridges with speeds of 45 mph and below must have railings that
meet TL‐2 criteria or greater.
- Bridges on the NHS must have railings that meet TL‐3 or greater,
regardless of design speed.
TL‐2
- Bridges with speeds of 50 mph and above must have railings that
meet TL‐3 criteria or greater.
- A TL‐5 or greater railing should be considered if any of the following
criteria are met
- Sustained longitudinal grade greater than 5%
- Horizontal curve radius less than 1,500 ft.
- High hazard environment below the bridge, such as a densely
populated area.
- In‐service performance of existing TL‐3 rail inadequate
TL‐3
- Bridges carrying mainline Interstate routes or system interchange
ramps
TL‐5
Test Level Selection
Until the Test Level guidance is published, this information will be applied on a project-by-project basis through the Standards and Policy Office.
SLIDE 32 2019 Bridge Design Conference 2/14/2019 32
Bridge Railing – Evaluation Criteria for Modifications
Impact forces based on test level
Strength
Tall enough?
Stability
Will it snag?
Geometry
Known performance issues?
In‐Service Performance
- Modifications for traditional installations are discouraged
- Modification for historic bridges and other special cases will
require documentation and supporting calculations
- Lettings on or after Dec. 31, 2019 (Bridge Railing)
- MASH updates + Q&A via AASHTO Committee on
Design
- https://design.transportation.org/mash‐
implementation/
- FHWA will discontinue issuing eligibility letters
December 2019
- Each State DOT will develop a process for determining
the crashworthiness of roadside safety hardware used
- n the NHS
- NCHRP Web Only 157 Evaluation of Existing Roadside
Safety Hardware
- NCHRP 20‐07(395) MASH Equivalency of NCHRP
Report 350‐Approved Bridge Railings
Bridge Railing – MASH Updates Summary
SLIDE 33 2019 Bridge Design Conference 2/14/2019 33
Eliz Elizab abeth Phillip illips ep ephill illip ips@ s@indot.in in.g .gov Mark Mark Or Orton ton Mort Morton@
ndot.in.gov Kat Katherine Smu Smutzer ksmu mutz tzer@ er@indot.in
Pe Peter Wh White pewhit pewhite@ e@ind indot. t.in.gov
General Email for Design Manual Inquiries DesignManualInquiries@indot.in.gov
Offi ffice of
Standards and and Polic licy
QUESTI QUESTIONS ONS
