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Guardrail Training
July 2016
Design Standards Index 400 - Guardrail
Presenter:
From the FDOT Roadway Design Office in Tallahassee…
2
Design Standards Index 400 - Guardrail
Course
B Breakdown:
Module 1 New Index Sheets Nos. 1-10 (Part A)
Module 2 New Index Sheets Nos. 11-22 (Part B)
Module 3 Instructions for Design Standards (IDS)
Module 4 Design Tool – Length of Need (Excel)
3
Design Standards Index 400 - Guardrail
7
Design Standards Index 400 - Guardrail
MODULE 1: Index Overview – Sheets 1 thru 10
Why change?...
Clarity. Updates. Effectiveness.
9
Design Standards Index 400 - Guardrail
10
Design Standards Index 400 - Guardrail
Implementation Schedule…
Roadway Design Bulletin 16-01
The Index Sheets and Instructions for Design Standards discussed refer to the
February 1st DSR to the 2016-17 Design Standards eBook. The Specifications referred
to will soon be available as Modified Special Provisions (MSPs).
The draft Specifications (MSPs) and PPM language are currently in Bulletin 16-01.
These documents are available for use at the option of the Districts for all projects
let prior to July 1st, 2017.
On July 1st, 2017 this update will become mandatory, as it will be released with the
2017-18 Design Standards eBook.
11
Design Standards Index 400, Sheet 1
Table of Contents and General Notes:
• Added Table
of Contents
• Re-ordered
sheets in an
intuitive
sequence
12
Design Standards Index 400, Sheet 1
Table of Contents:
Sheet Organization/Groupings:
2-3) Guardrail run types
4-5) Basic components
6) Guardrail Cross-Sections
7-12) End Treatments:
• Approach “Terminal”
• Trailing “Anchorage”
• CRT (with layouts)
13-16) Transition Connections to
Rigid Barriers
17-18) Example guardrail layouts
showing how segments
above will fit together
19-20) Guardrail supplements
• Rub Rail
• Pipe Rail
21) Modified Post Mounts
22) Miscellaneous Details
13
Design Standards Index 400, Sheet 1
General Notes: NOTES Highlights:
1. Use Spec 536. No project
specific shop drawings
needed.
2. This is considered 31”
height Guardrail (based on
MGS design)
3. Components based on
AASHTO-AGC-ARTBA Design
4. Post Bolt type
5. Hex Bolt type
6. Asphalt type
7. Options for Contractor
when posts fall within 4’ of
sidewalk
8. How to connect to existing
guardrail (transition)
9. Plans Callouts
10. Guardrail Length
Measurement 14
Design Standards Index 400, Sheet 2
General, TL-3 Guardrail Details:
• Configuration
for “General”
run of W-
beam
guardrail
• Applicable for
TL-3 Design
Speed and
below
15
Design Standards Index 400, Sheet 2
General, TL-3 Guardrail Details:
• Configuration
for “General”
run of W-
beam
guardrail
• Applicable for
TL-3 Design
Speed and
below
16
Design Standards Index 400, Sheet 2
General, TL-3 Guardrail Details:
21
Design Standards Index 400, Sheet 3
Low-Speed, TL-2 Guardrail Details:
23
Design Standards Index 400, Sheet 4
W-Beam and Thrie-Beam Panel Details:
• Panel Options
Shown on
single Sheet
• Panels are
used in
General and
Low-Speed
Guardrail,
Approach
Transitions,
End
Treatments
Etc…
24
Design Standards Index 400, Sheet 4
W-Beam and Thrie-Beam Panel Details:
Traditional Panel Jargon:
• Double Panel = 25’-0”
• Full Panel = 12’-6”
• Half Panel = 6’-3”
• Quarter Panel = 3’-1½”
25
Design Standards Index 400, Sheet 4
W-Beam and Thrie-Beam Panel Details:
• New
“Consolidated”
Steel Post type
• New variations of
Post length and
offset block
height are given
27
Design Standards Index 400, Sheet 5
Post and Offset Block Details:
Offset Block
Dimension is
6” x 8” Nominal
(5.5” x 7.5” Actual)
28
Design Standards Index 400, Sheet 5
Post Details:
• 2 Post Lengths (Depths)
• Standard ‘L’
• Deep Post ‘L’
30
Design Standards Index 400, Q1 Review!
End of 1st Quarter Review Questions!
1. What is the Post Spacing of TL-2, Low-Speed Guardrail?
12’-6”
2. At what Design Speed is TL-2 Guardrail Permitted?
45 mph and less
3. What Length Panel must contractors use at the end of a TL-2
Low-Speed Guardrail run? Why?
9’-4½” panel for transitioning to adjacent
segment’s midspan splice
4. At what length increment must designers plan a General or
Low-Speed Guardrail run? (excluding Approach Transitions
and End Treatments)
6’-3” increment
5. When else would a contractor use 9’-4½” or 15’-7½” Panels?
To transition new guardrail from existing guardrail
(establish midspan splice)
6. What is the “offset” length dimension of a Standard Offset
Block?”
7½” (8” Nominal) 31
Design Standards Index 400, Sheet 6
Guardrail Sections:
Summary:
• Guardrail Heights
& Depths
• Adjacent Grading
(a.k.a. Slopes)
• 2” Misc. Asphalt
Mow Strip
• Concrete
Sidewalk
• Curb Conditions
• Shoulder Gutter
• Rub Rail
32
Design Standards Index 400, Sheet 6
Guardrail Sections:
Types of Guardrail:
• The Heights, ‘H’, and Depths, ‘D’, are used later in Standard drawings where
any of the below guardrail types may be used.
33
Design Standards Index 400, Sheet 6
Guardrail Sections:
Slope Break Condition, “Deep Posts” NEW!
• Contractor may only use Deep Posts where called for in the Plans.
PPM 4.4.6.2 “With approval of the District Design Engineer and where right-of-way is
restricted (i.e. constrained condition), the Deep Post guardrail option, as detailed in
Design Standards, Index 400 Slope Break Condition, may be used in lieu of providing a 2
ft. setback to the slope break point. Coordinate the use of the Deep Post guardrail
option with the District Drainage Engineer and District Maintenance Engineer.” 34
Design Standards Index 400, Sheet 6
Guardrail Sections:
Typical Grading and Pavement Placement Detail
• Provides pre-
defined
Lengths ‘LE’
that will
accommodate
all APL
Terminals (for
simpler Plans
design)
39
Design Standards Index 400, Sheet 7
Approach Terminal Geometry, Parallel and Flared:
• Shows basic
geometry and
grading
requirements
for APL
Approach
Terminals
• Provides pre-
defined
Lengths ‘LE’
“Soft Stop” that will
accommodate
all APL
Terminals (for
simpler Plans
design)
40
“SKT”
Design Standards Index 400, Sheet 7
Approach Terminal Geometry, Flared:
• Same idea as
Sheet 7, but
shows
“Curbed” and
“Double
Faced”
segments
42
Design Standards Index 400, Sheet 8
Approach Terminal Geometry, Curbed:
• Nearly same as
previous
Standard, just
drafted more
clearly
45
Design Standards Index 400, Sheet 9
Trailing Anchorage - Type II:
• Begin/End Guardrail
Station called out –
Corresponds to
Roadway Plans callout
(Stationing and Offset
given at Face of
Guardrail) – Length of
guardrail measured
from here
Anchor Block
Option Removed
46
Design Standards Index 400, Sheet 10
End Treatment Component Details:
• Component
Details are
used in Type II
and CRT End
Treatments
(on the
previous and
following
pages,
respectively)
• Construction
Stuff!
47
Design Standards Index 400, Q2 Review!
End of 2nd Quarter Review Questions!
1. What is the minimum distance required from the back of
post to the front slope break?
2 feet
2. For Guardrail adjacent to curb, what’s the distance
between the face of Guardrail and the face of curb?
0” or 5”, defined by the Designer in the Plans
3. What is the maximum slope permitted for all approach
grading to Guardrail or End Treatments?
1:10 or flatter
4. For what “condition” are Deep Posts intended to be used?
“Slope Break Condition” (with approval of DDE)
5. To what distance, behind post(1) of an approach terminal,
must the 1:10 slope be maintained?
6 feet behind face of guardrail @ post(1)
6. What type of curb must be used in front of an Approach
Terminal?
Type E curb
7. Where is the “Type II” End Treatment used?
On Trailing (downstream) guardrail ends only
(outside of opposing lane’s clear zone) 48
Design Standards Index 400 - Guardrail
MODULE 2: Index Overview – Sheets 11 thru 22
• This is the
same as the
previous
Standard, only
detailed more
clearly.
50
Design Standards Index 400, Sheet 12
Layout for Controlled Release Terminal (CRT) System:
• Used for 90 degree
intersection of
principle roadway
and side road or
driveway
• Draw
corresponding
dimensions and
radius in the Plans
• When terminating
with a CRT End
Treatment, the
guardrail extends
15’-7½” from
Match Line
51
Design Standards Index 400, Sheet 12
Layout for Controlled Release Terminal (CRT) System:
• MASH Tested
• Applicable to all
Design Speeds
• About 12’-6”
shorter than old
“Detail J” from
Rigid Barrier
(about 25’ shorter
including previous
barrier overlap)
• New raised
‘Alignment Curb’
required
• Section Views on
Sheet 15
53
Design Standards Index 400, Sheet 13
Approach Transition Connection to Rigid Barrier, General TL-3:
54
Design Standards Index 400, Sheet 13
Approach Transition Connection to Rigid Barrier, General TL-3:
• Begin/End Rigid Barrier Station called out - Different from Begin/End Guardrail Station
(governed by Thrie-Beam Terminal Connector with its Edge flush with Rigid Barrier)
Guardrail’s 7¼” overlap with the Rigid Barrier should be drawn this way in Plans
• End Transition of Curb – This is where typical curb type begins, if here on project
(e.g. Type F, Shoulder Gutter) Starts 28’-1½” from Begin/End Guardrail Station
55
Design Standards Index 400, Sheet 13
Approach Transition Connection to Rigid Barrier, General TL-3:
• Rigid Barrier Shoulder Line: Aligns with “Standard Shoulder Line” of Shoulder
Gutter as shown in Index 300. This Shoulder Gutter aligns at Section E-E.
• Taper to Guardrail Offset per the Plans: If roadway guardrail has a different lateral
offset than the bridge railing guardrail, then your “Begin/End Taper” callout is
given at Section E-E. (Starts 28’-1½” from Begin/End Guardrail Station)
*This leads to typical section, generally meeting PPM Fig 4.4.12
• End Transition of Curb – This is where typical curb type begins, if here on project
(e.g. Type F, Shoulder Gutter; Starts 28’-1½” from Begin/End Guardrail Station)
56
Design Standards Index 400, Sheet 13
Approach Transition Connection to Rigid Barrier, General TL-3:
• Taper to Guardrail Offset per the Plans: This guardrail taper generally leads to
these typical sections. Per PPM 4.4.12…
57
Design Standards Index 400, Sheet 13
Approach Transition Connection to Rigid Barrier, General TL-3:
Sneak Peak of Sheet 17… the bigger picture of tapering to typical section!
Section E-E…
Begin Taper!
• Taper to Guardrail Offset per the Plans: This guardrail taper generally leads to
these typical sections. Per PPM 4.4.12…
58
Design Standards Index 400, Sheet 14
Approach Transition Connection to Rigid Barrier, Low-Speed TL-2:
• ALL NEW!
• MASH Tested
• Applicable to
Design Speeds
≤ 45 mph
• New raised
‘Alignment Curb’
required
• Section Views
on Sheet 15
59
Design Standards Index 400, Sheet 14
Approach Transition Connection to Rigid Barrier, Low-Speed TL-2:
• ALL NEW!
• MASH Tested
• Applicable to
Design Speeds
≤ 45 mph
• New raised
‘Alignment Curb’
required
• Section Views
on Sheet 15
60
Design Standards Index 400, Sheet 14
Approach Transition Connection to Rigid Barrier, Low-Speed TL-2:
• Begin/End Rigid Barrier Station called out - Different from Begin/End Guardrail Station
• End Transition of Curb – This is where typical curb type begins, if here on project
(e.g. Type F, Shoulder Gutter) Starts 18’-9” from Begin/End Guardrail Station 61
Design Standards Index 400, Sheet 14
Approach Transition Connection to Rigid Barrier, Low-Speed TL-2:
• Rigid Barrier Shoulder Line: Aligns with “Standard Shoulder Line” of Shoulder
Gutter as shown in Index 300. This Shoulder Gutter aligns at Section E-E.
• Taper to Guardrail Offset per the Plans: If roadway guardrail has a different lateral
offset than the bridge railing guardrail, then your “Begin/End Taper” callout is
given at Section E-E. (Starts 18’-9” from Begin/End Guardrail Station)
*This leads to typical section, generally meeting PPM Fig 4.4.12
• End Transition of Curb – This is where typical curb type begins, if here on project
(e.g. Type F, Shoulder Gutter; Starts 18’-9” from Begin/End Guardrail Station)
Design Standards Index 400, Sheet 15
Approach Transition Connection Details:
• Shows Cross
Section details
for Approach
Transitions on
previous
Sheets.
• Provides curb
transitions for
three types of
curb Options
1. Shoulder
Gutter
2. Raised Curb
3. No Curb
63
Design Standards Index 400, Sheet 15
Approach Transition Connection Details:
Curb Sections – Alignment Curb Segment
• “Alignment Curb”
• aligns with face of rigid barrier
• reduces potential for vehicle snagging at start of Rigid
Barrier (per TTI recommendation)
• follows same lateral offset (both curb and face of
guardrail) from Section B-B to D-D
64
Design Standards Index 400, Sheet 15
Approach Transition Connection Details:
Curb Sections – Transition to Shoulder Gutter Option (1 of 3)
Section E-E, Raised Curb Established (e.g. Type F or Type E). This
will generally keep its face aligned with the Rigid Barrier’s
shoulder line (same as Alignment Curb).
At Section E-E, begin the guardrail offset taper to typical section
(Sheet 6).
• “Hybrid” of
previous
Double Faced
Transition and
MASH-Tested
TL-3 Approach
Transition
• Adds 12’-6”
barrier overlap
needed to
transition
guardrail to
Rigid Barrier
Width
68
Design Standards Index 400, Sheet 16
Approach Transition Connection to Rigid Barrier, Double Faced:
• Begin/End Double Faced Guardrail Station called out – Corresponds to Roadway Plans callout –
Length of guardrail measured from here
• Begin/End Rigid Barrier Station called out - Different from Begin/End Guardrail Station
(Required for Double Faced Guardrail width to transition into the narrower Rigid Barrier)
Guardrail’s 13’-1¼” overlap with the Rigid Barrier should be drawn this way in Plans.
• Length of Approach Transition, ‘LA’ – Has the same post spacing as the ‘General’ Approach
Transition. The curb is omitted, because the guardrail panels are held away from the Rigid
Barrier by the added offset blocks (reducing vehicle snagging).
69
Design Standards Index 400, Sheet 16
Approach Transition Connection to Rigid Barrier, Double Faced:
• Rigid Barrier – “Full” Double Faced Barrier per Index 410. It is narrower than Double
Faced Guardrail System
• Trimmed Std. Offset Blocks to Rigid Barrier – Wider guardrail system transitioning to
Rigid Barrier width. The reason for the guardrail overlapping with the Rigid Barrier!
• Taper to Guardrail Offset per the Plans – Similar to Section E-E in that this is where
the Plans will begin transition to a different guardrail offset if needed (40’-7½” from
Begin/End Guardrail Sta.)
70
Design Standards Index 400, Q3 Review!
End of 3rd Quarter Review Questions!
1. When is a CRT configuration used?
Used for 90 degree intersections of principle
roadways with side roads or driveways
2. For Approach Transition Connections, when is the
guardrail panel overlap with Rigid Barrier of about 12’-6”
required?
Double Faced Guardrail Connections
3. For single faced Approach Transition Connections, what is
the location difference between the Begin Guardrail
Station and the face of the Rigid Barrier? (in inches)
7¼”
4. All single faced Approach Transition Connections require
an Alignment Curb underneath… True or False?
True
5. All double faced Approach Transition Connections require
an Alignment Curb underneath… True of False?
False
6. For single faced Approach Transition Connections, at what
‘Section’ on the Index Sheet do you begin the guardrail
Taper (usually headed towards 2’ from shoulder line)?
Section E-E 71
Design Standards Index 400, Sheet 17
Layouts to Rigid Barrier, Single Barrier Approach or Median Crossover:
• Provides
Example
Layout “Types”
that will
correspond to
callouts in the
Plans
• Shows how
segments in
previous
sheets connect
together
72
Design Standards Index 400, Sheet 17
Layouts to Rigid Barrier, Single Barrier Approach:
• Shows Approach Transition, General Guardrail, and Approach Terminal End Treatment as one system.
NOTE: For shortest case of Rigid Barrier end protection, General Guardrail segment may be omitted
(simply ‘LA’ + ‘LE’)
• Begin/End Guardrail Stations called out – Corresponds to Roadway Plans callout – Corresponds to
callouts on preceding sheets – Defines length of Guardrail
• Begin/End Taper Stations called out – The circled Taper Sta. will generally
look like one of these! From PPM Figure 4.4.12
Design Standards Index 400, Sheet 17
Layouts to Rigid Barrier, “Median Crossover Guardrail”:
• Shows layout for shielding Rigid Barriers of dual bridges, where the concrete railing across
the median is within the clear zone (this places the back of the shielding guardrail in the
opposing lane’s clear zone as well)
• The “Median Guardrail Crossover” is most efficient design for the shortest Length of Need
• The new ‘Guardrail Length of Need Program’ assists with this design, providing station
and offset information. We’ll cover specifics of ‘Double Faced Approach Terminals’ and
‘Crash Cushions’ when we discuss this later.
75
Design Standards Index 400, Sheet 17
Layouts to Rigid Barrier, “Median Crossover Guardrail”:
• Begin/End Double Faced Guardrail Stations called out – Corresponds to Roadway Plans
NOTE: The Double Faced Guardrail Pay Item applies from the Rigid Barrier Connection to
the End Treatment (even over the single faced Approach Transition Connection).
• Begin/End Taper Stations called out - Corresponds to Roadway Plans callout. The station
and offset callouts define the linear taper rate for the contractor.
NOTE: The ‘Guardrail Length of Need Program’ assists with providing these
stations and offsets.
76
Design Standards Index 400, Sheet 17
Layouts to Rigid Barrier, “Median Crossover Guardrail”:
• Shows how
segments in
previous
sheets connect
together
78
Design Standards Index 400, Sheet 18
Layouts to Rigid Barrier, Double Faced Approach:
• Shows Approach Transition, General Guardrail, and Approach Terminal End Treatment as one system.
NOTE: For shortest case of Rigid Barrier end protection, General Guardrail segment may be omitted
(simply ‘LA’ + ‘LE’)
• Begin/End Double Faced Guardrail Stations called out – Corresponds to Roadway Plans callout –
Corresponds to callouts on preceding sheets – Defines length of Guardrail
• Previous
Standard had
referenced
AASHTO-ARTBA-
TF13 “Guide to…
Barrier
Hardware”, but
this did not show
installed Rub Rail
in finished
condition
83
Design Standards Index 400, Sheet 20
Pedestrian Safety Treatment – Pipe Rail:
• Pipe Rail segments are required
where Steel Posts will be located
within 4’ of sidewalks or shared
use paths
84
Design Standards Index 400, Sheet 21
Special Steel Post, Encased Post, Frangible Leave Out:
• NEW AND
IMPROVED!
(mostly)
• “Modified Mounts”
allow different post
mounting options
for the scenarios of:
• Posts atop a
concrete
structure
• Posts over
shallow
underground
utilities
• Post atop
concrete
surface
(sidewalk)
85
Design Standards Index 400, Sheet 21
Special Steel Post for Concrete Structure Mount:
• Contractor may use Special Steel Posts when it is called for in the Plans or as-needed
(billed beyond the Plans quantity).
• If a post falls entirely upon a concrete structure (base plate beyond 3” from the
edge), a Special Steel Post is used (with base plate mounted into the structure via
adhesive-bonded anchor bolts).
86
Design Standards Index 400, Sheet 21
Special Steel Post for Concrete Structure Mount:
If a post falls on the concrete edge, then this is called an “Edge Conflict”, and the
contractor has two options:
• Option 1, Standard Post: Move the post up to a quarter span in the direction away
from the structure, and plant the post in the soil
NOTE: The contractor is allowed to use up to
2 additional Offset Blocks to miss the structure
• Option 2, Special Steel Post: Move the post up to a quarter span in the direction of the
structure, and use a Special Steel Post with its base plate entirely atop the structure 87
Design Standards Index 400, Sheet 21
Encased Post for Shallow Mount (Over Underground Obstacles):
88
Design Standards Index 400, Sheet 21
Frangible Leave-out for Concrete Surface Mount:
• ALL NEW! If a post falls atop a concrete surface or sidewalk (undesirable), then the
contractor must use a “Frangible Leave-Out” around the base of the post.
• The Frangible Leave-out involves blocking out the concrete around the base of the post and
backfilling it with low-strength “Flowable Fill” (max 150 psi).
This allows the post to rotate correctly upon vehicle impact.
• These Leave-outs can either be called out in the Plans for predictable post locations, or the
contractor can use them as-needed (billed beyond the Plans quantity). 89
Design Standards Index 400, Sheet 22
Barrier Delineators, Reduced Post Spacing, Bolt System:
• LAST INDEX SHEET!
• Includes
Miscellaneous
Details for the
Contractor like
Barrier Delineation
and Standard Bolt
Information
90
Design Standards Index 400, Sheet 22
Reduced Post Spacing for Hazards (Reduced Setback Clearance) :
• When an aboveground hazard
is within 5’-0” behind the face
of guardrail, reduced post
spacing may be used to
reduce the “Setback”
requirement to the hazard
(see PPM Table below)
From PPM: Table 4.4.2 Minimum Barrier Setback: • The Standard also handles
Low-speed Guardrail 12’-6”
spacing, explaining that the
spacing sequence remains the
same, but with the 12’-6”
adjacent to the 6’-3” spacing.
91
Design Standards Index 400, Q4 Review!
End of Game Review Questions!
(Everyone wins!... of course)
1. What station and offset callouts are required to define a
Guardrail Crossover for Median configuration?
Begin/End Guardrail, Begin/End Taper
2. When is Rub Rail required?
Double Faced Guardrail, median side, Slope > 1:10
3. When is Pipe Rail required?
Steel Posts within 4 feet of sidewalk or shared use path
4. Concerning Pipe Rail, the Roadway Plans should assume steel
posts are used (True or False)
True
5. How many options does a contractor have when a post has an
“Edge Conflict” with a structure?
Two – Standard Post in soil or base plate (± quarter span)
6. When is a Frangible Leave-Out used?
When posts fall atop sidewalk (or concrete slab)
7. When is a Reduced Post Spacing segment used?
For Hazard setbacks < 5 feet behind face of guardrail
92
Index 400 Guardrail – IDS
MODULE 3:
Instructions for Design Standards (IDS)
Where is it?...
94
Index 400 Guardrail – IDS Part B
Length of Need Concept:
95
Index 400 Guardrail – IDS Part B
Length of Need Concept:
Quick Example:
Design Speed = 45 mph
AADT = 5000 veh/day
Y = 8.5 Ft. (by design, guardrail offset plus flare effect)
Back of Hazard = 22 Ft. (from ‘Edge of Traffic Lane’)
Clear Zone = 24 Ft. (from PPM Table 4.2.1)
Lateral Area Concern, LA = 22 Ft.
Runout Length, LR = 160 Ft. (from RDG Table 5-10b)
= (22-8.5) / (22/160)
X = 98.2 Ft.
Index 400 Guardrail – IDS Part B
Length of Need, Quick Example:
Notice that Lg, the “Length of Gating”, was ignored in the previous
Calculation. This is the “break away” stuff, so we only count the
“non-gating” re-directive segment for Length of Need. We’ll talk
more about this in Part C.
98
Index 400 Guardrail – IDS Part C
End Treatments:
99
Index 400 Guardrail – IDS Part C
End Treatments – 1. Trailing Anchorage:
100
Index 400 Guardrail – IDS Part C
End Treatments – 2. Approach Terminal:
1. Flared: Use where raised curbs are not present and lateral clearance
is available. This is the preferred option, because it provides shortest
Length of Need requirement for shielding hazards and reduces driver
propensity to shy away from the End Treatment under normal
conditions.
Allow for at least this much length in the Plans, measured from Post (1)
This length should not overlap with other design segments, like Approach
Transitions ‘LA’ or trailing anchorages ‘LT’. 105
Index 400 Guardrail – IDS Part C
End Treatments – 2. Approach Terminal:
TL-3 Example:
Add ‘Design Length’ notes to the Roadway Plan callout and Summary of Guardrail
per the IDS (e.g. "Design Length ≤ 37.5 Ft., See Summary of Guardrail Note"). 106
Index 400 Guardrail – IDS Part C
End Treatments – 2. Approach Terminal:
Gating Terminal Concept for ‘LON’ Design:
Most Approach Terminals have
break-away “gating” between posts 1 and 3:
Only specify a Non-Gating Terminal in the Plans where this space savings is required
to fit. In the Roadway Plan view, specify "Non-Gating" preceding the Approach
Terminal callout. Additionally, add a Summary of Guardrail note per the IDS. 108
Index 400 Guardrail – IDS Part C
End Treatments – 3. Crash Cushions:
Crash Cushions May be Used for Doubled Faced
Guardrail End Treatments
Remember:
• Pipe Rail segments are required
where Steel Posts will be located
within 4’ of sidewalks or shared
use paths
Pipe Rail Callouts and Length Example: • Designers should generally
assume steel posts are used and
include pipe rail callouts and
quantities in the Plans (to give
contractor steel or timber post
option)
• Pipe Rail must terminate outside
of End Treatment segments (At
least 3'-1½" outside of 'LE', 'LT',
and/or Crash Cushion
Measure length along the centerline, including segments).
curvature effects. Include in the Summary of • Begin/End Pipe Rail Station
corresponds to the Plans
Guardrail Box (See the BOE Manual, CH 8) callouts
111
Index 400 Guardrail – IDS Part F
Rub Rail:
Remember:
• Use Rub rail only for
Rub Rail Callouts and Length Example: median slopes greater
than 1:10
• Place Rub Rail outside of
End Treatment Segments
(Approach Terminal ‘LE’,
Trailing Anchorage ‘LT’)
and Crash Cushion
Transition segments.
Measure length along the centerline, including
curvature effects. Include in the Summary of
Guardrail Box (See the BOE Manual, CH 8)
112
Index 400 Guardrail – IDS Part G
Deep Posts:
Remember:
• “With approval of the
District Design Engineer
and where right-of-way is
Deep Post Callouts Example: restricted (i.e. constrained
condition), Deep Posts may
be used with the slope
break located at the post
centerline as defined per
the Slope Break Condition
in the Index.”
• Deep Posts are only
To determine the quantity (EA.) of Deep Posts, divide the length permitted for segments
needed by the post spacing (6.25 Ft.) and add one. Place quantity in with a post spacing of 6'-3"
the Summary of Guardrail Box under Special Guardrail Posts (Deep or less.
Posts) See the BOE Manual, CH 8 for details.
113
Index 400 Guardrail – IDS Part H
Modified Mounts – Special Posts:
Remember:
1. Special Steel Post
(with Base Plate) for
Concrete Structure
Mount
3. Frangible Leave-Out
The designer can estimate where these posts will be in the Plans to for Concrete Surface
include in the Summary of Guardrail Box and Summary of Pay Items (sidewalks)
And/Or…
The contractor will use unforeseen items as-needed (billed beyond
114
Plans quantity)
Index 400 Guardrail – IDS Part H
Special Posts:
Special Post Callouts and Length Example:
• “This Crossover Guardrail layout includes a taper segment, which reduces the Length of Need
required for shielding the opposing lane's concrete railing while also using Double Faced
Guardrail to shield the opposing lane's traffic.”
• In the Plans, call out the Begin/End Double Faced Guardrail Stations and Offsets as well as the
Begin/End Taper Station and Offsets where shown above.
• For quantities, the entire length of guardrail shown above is considered “Double-Faced”
• In the Plans, graphically show the double faced guardrail panels as well extending to the point
shown above.
118
Index 400 Guardrail – IDS Part J
Median Crossover Guardrail (Double Faced):
• The FDOT ‘Guardrail Length of Need’ Excel Program will assist with providing these Station
and Offsets above. We will use in the next session...
Index 400 Guardrail – IDS Part K
Reduced Post Spacing Segments
Remember:
• When a rigid hazard is
within 5’-0” of the face
of guardrail, reduced
post spacing may be
used to reduce the
“Setback” requirement
to the hazard (see PPM
Table 4.4.2)
120
Index 400 Guardrail – IDS Part L
Additional Offset Blocks
• The designer may call out up to two
additional offset blocks where
needed to avoid a ground level
obstructions (non-consecutive
preferred)
121
Index 400 Guardrail – IDS Part L
Additional Offset Blocks
• IMPORTANT: When adding additional
offset blocks, the required “Setback” to a
Hazard per PPM Table 4.4.2 must be
increased by 7.5” per added Offset Block.
• Adjusted Setback =
(3’-2”) + (7.5” + 7.5”) =
4’-5”
122
Index 400 Guardrail – IDS Part M
CRT Segments:
Remember…
Typical Sections: Design and label the 'Lateral Offset' from the Face
of Curb or Edge of Traffic Lane as it corresponds
to the Guardrail Sections sheet in the Index.
(PPM CH2.3 “Shoulders” & 4.4.6.1 “Barrier Offset”)
Cross Sections &
Typical Sections: Meet the offset requirements of the PPM and the
adjacent grading requirements as shown in the
Index.
Index 400 Guardrail – Plans Content
Roadway Plan: Label the Station and Offset (From the Station Reference, Centerline or
Baseline) for the Face of Guardrail at the locations with corresponding
Begin/End Stations shown in the Index, including the following:
1. Begin/End GR. Stations label the limits of the guardrail length measurement, generally
located at centerline of Post (1) in End Treatments and/or at the Terminal Connector splice
of an Approach Transition Connection segment. See the Index layouts for details.
If Low-Speed (TL-2) guardrail is required, change this label to "Begin/End TL-2
GR."Instructions for Design Standards Topic No. 625-010-003 Index 400 Guardrail February
2016 6
2. Begin/End Taper Stations label the offset Face of Guardrail locations for the start and
end of linear tapers (e.g. for a change in typical section or for a Crossover Taper segment).
The Guardrail Taper Rate requirements above will govern these transitions.
3. Begin/End CRT(8, 16, 24, or 32) Ft. R. Station labels the starting point for the Controlled
Release Terminal (CRT) System and the radius, 'R'.
4. Begin/End Pipe Rail Stations label the limits of Pipe Rail length measurement, generally
located at centerline of the Terminal Posts.
5. Begin/End Rub Rail Stations label the limits of Rub Rail length measurement, generally
located at centerline of the Terminal Posts. NOTE: This is not depicted in the Index.
For Double Face Guardrail, place labels pointing to Face of Guardrail on the side requiring
the Rub Rail. If Rub Rail is required on both sides, use a different label on each side or add
"(Both Sides)" to the callout.
6. Begin/End Half Sp. Stations label the limits of Reduced Post Spacing at 3'-1½". The
overall length of this segment must be a multiple of 6'-3".
7. Begin/End Quarter Sp. Stations label the limits of Reduced Post Spacing at 1'-6¾". The
overall length of this segment must be a multiple of 6'-3".
Index 400 Guardrail – Plans Content
Roadway Plan:
Label the Station and Offset at the Face of Guardrail for the
following guardrail end features:
1. TL-2 Flared Terminal
2. TL-2 Parallel Terminal
3. TL-2 Dbl. Faced Terminal
4. TL-3 Flared Terminal
5. TL-3 Parallel Terminal
6. TL-3 Dbl. Faced Terminal
7. TL-3 C.C.
8. TL-4 C.C.
9. Type II Anchorage
10. CRT End Treatment
11. TL-2 Apprh. Trans.
12. TL-3 Apprh. Trans.
NOTE: The above labels may be included with the Begin/End Guardrail Station callouts.
127
Index 400 Guardrail – Plans Content
Roadway Plan:
Label the Station and Offset at the Face of Guardrail for the
following miscellaneous guardrail features:
1. Encased Post
2. Special Steel Post
3. Frangible Leave-Out
4. Deep Post
5. Two Offset Blocks
6. Three Offset Blocks
7. GR. Slope Guard.
128
Index 400 Guardrail – Plans Content
Summary of Guardrail Table:
Include Pay Items from the FDOT Design Quantities and Estimates System (DQE),
the Basis of Estimates Manual (BOE), and Specifications Section 536.
130
Index 400 Guardrail – Plans Content
Guardrail Length Measurement Examples:
• Include End Treatment and
Approach Transition
lengths added as the basic
connecting guardrail type,
such as General or Low-
Speed Guardrail
• End Treatment and
Approach Transition Pay
Items consider costs as
over-and-above basic
guardrail
‘LA’ + 7¼”
+ ‘LE’ =
84.3’
134
Index 400 Guardrail – Plans Content
Taper to Different Guardrail Offset Example:
• What is the likely offset difference between the shoulder line and
the Face of Guardrail?
2 feet per PPM
• What is the approximate Taper Rate shown here?
1:15
• Using the Design Standard drawing for approach transitions, where
did this Taper shown begin? (See Next Page)…
135
Index 400 Guardrail – Plans Content
Taper to Different Guardrail Offset Example:
137
Index 400 Guardrail – Plans Content
Miscellaneous Guardrail Layout Examples (from IDS):
138
Index 400 Guardrail – Plans Content
Miscellaneous Guardrail Layout Examples (from IDS):
139
Index 400 Guardrail – Plans Content
Miscellaneous Guardrail Layout Examples (from IDS):
140
Index 400 Guardrail – Plans Content
Miscellaneous Guardrail Layout Examples (from IDS):
141
Guardrail Length of Need v1.0
1
Guardrail Length of Need v1.0
Where is it?...
2
Guardrail Length of Need v1.0
“Part A” Drawing:
Input: Comment:
Direction of Near Lane Traffic for relative stationing calculations
AADT (Vehicles Per Day)
Design Speed (MPH)
Approach Face of Hazard Station enter as total feet (do not input a plus sign)
Length of Hazard, LH (Ft.)
the lesser distance from the 'Edge of Traffic Lane' to the 'Clear
Lateral Area Concern, LA (Ft.)
Zone Limit' or 'Back of Hazard'
the typical guardrail offset from the 'Edge of Traffic Lane,' near
Lateral Offset of Guardrail, LO (Ft.)
the 'Hazard' location (outside of flare)
"Gating" Terminals typically have a 'Start LON' at Post 3 or Post
4, per the APL Drawings. For "Non-Gating" Terminals, the 'Start
Length of Gating, LG (Ft.) LON' is at 'Post 1' (LG =0).
NOTE: The flare rate effect on LG, assumed parallel to the
roadway, is negligible and may be omitted.
4 Ft. Max. per Index 400 detail, measured offset at Post(1);
Terminal Flare @ Post(1) (Ft.)
enter zero for "Parallel" Terminals
default value is acceptable at 35'-0", but this may be refined per
Flare Taper Length (Ft.)
specific APL drawing (Input used to calculate 'Y')
Guardrail Length of Need v1.0
Part A – Example:
Given:
Design Speed = 55 mph
AADT = 5000 veh/day
Clear Zone = 30 feet
(PPM Table 4.2.1)
Flare = 4 feet
Terminal Type = Gating
Input: Comment:
Is this a 2-lane, 2-way road with the Hazard in the Far Lane's
PART B Required? Y/N
Clear Zone limit? If "No" Part B will be excluded from the
(User Input Needed) (Toggle) placement calculation output below.
the lesser distance from the 'Edge of Traffic Lane' (Far Lane)
Lateral Area Concern, LA (Ft.)
to the 'Clear Zone Limit' or 'Back of Hazard'
the typical guardrail offset from the 'Edge of Traffic Lane'
Lateral Offset of Guardrail, LO (Ft.)
(Far Lane), near the 'Hazard' location (outside of flare)
per the APL Drawings, "Gating" Terminals typically have a
'Start LON' at Post 3 or Post 4. For "Non-Gating" Terminals,
Length of Gating, LG (Ft.) the Start LON is at 'Post 1' (LG =0).
NOTE: The flare rate effect on Lg, assumed parallel to the
roadway, is negligible and may be omitted.
4 Ft. Max. per Index 400 detail; measured to Post(1); enter
Terminal Flare @ Post(1) (Ft.)
zero for 'Parallel' Terminals
default value is acceptable at 35'-0", but this may be refined
Flare Taper Length (Ft.)
per specific APL drawing (Input used to calculate 'Y')
Guardrail Length of Need v1.0
Part B – Example (Far Lane):
Given:
Design Speed = 55 mph
AADT = 5000 veh/day
Clear Zone = 30 feet
(PPM Table 4.2.1)
Flare = 0 feet (for example)
Terminal Type = Gating
Adjusted to
Nearest 6’-3”…
Guardrail Length of Need v1.0
“Part D”
Drawing:
Input: Comment:
Direction of Near Lane Traffic for relative stationing calculations
AADT (Vehicles Per Day)
Design Speed (MPH)
Begin/End Rigid Barrier Sta. enter as total feet (do not input a plus sign); located at the end
(@ guardrail connecting location) of the 'Rigid Barrier' (not the Begin/End Guardrail Sta.)
the starting guardrail offset from the 'Edge of Near Traffic Lane'
Lateral Offset of Guardrail, LO (Ft.) at the location where the guardrail connects to the 'Rigid
Barrier' (determined by the designer)
the lateral distance from the 'Edge of Near Traffic Lane' to the
Lateral Area Concern, LA (Ft.) far edge of the opposing 'Rigid Barrier' (i.e. Concrete Traffic
Railing) across the median
the length of the guardrail Approach Transition Connection prior
to the start of the taper; per Index 400 options,
Parallel Approach Trans. Length, LP1 (Ft.) TL-3=27.5 Ft. and TL-2=18.2 Ft.
Note: This is measured from the end of the 'Rigid Barrier' (not
the 'Begin/End Guardrail Sta.')
the length of the parallel segment required for the Approach
Parallel Approach Terminal Length, LP2 (Ft.)
Terminal, just beyond the taper; Per Index 400, TL-3 = 56.3 Ft.
"Gating" Terminals typically have a 'Start LON' at Post 3 or Post
Length of Gating, LG (Ft.) 4, per the APL Drawings. For "Non-Gating" Terminals, the 'Start
LON' is at 'Post 1' (LG =0).
the linear taper rate for the Median Crossover Segment; 1:10 for
Taper Rate of Crossover, 1:TR (Ft.)
Design Speeds ≤ 45 MPH and 1:15 for Design Speeds > 45 MPH.
the longitudinal "skew" distance between the guardrail's
connecting Rigid Barrier end and the "Hazard" Rigid Barrier end
Rigid Barrier Skew, S (Ft.)
(across the median). For the direction opposite the drawing
dimension, use a negative value.
Guardrail Length of Need v1.0
Part D – Example - Median Crossover with Terminal:
Given:
Design Speed = 65 mph
AADT = 10,000 veh/day
Clear Zone = 36 feet
(PPM Table 4.2.1)
Terminal Type = Gating
Given:
Design Speed = 65 mph
AADT = 10,000 veh/day
Clear Zone = 36 feet
(PPM Table 4.2.1)
Terminal Type = Gating
Design Standards Index 400 - Guardrail
11
Design Standards Index 400 - Guardrail
THANK YOU!
QUESTIONS?
“Paper Program”
PART A: LENGTH OF NEED FOR NEAR LANE
Input: Comment:
Direction of Near Lane Traffic Westbound for relative stationing calculations
AADT (Vehicles Per Day)
Design Speed (MPH)
Approach Face of Hazard Station enter as total feet (do not input a plus sign)
Length of Hazard, LH (Ft.)
the lesser distance from the 'Edge of Traffic Lane' to the 'Clear
Lateral Area Concern, LA (Ft.)
Zone Limit' or 'Back of Hazard'
the typical guardrail offset from the 'Edge of Traffic Lane,' near
Lateral Offset of Guardrail, LO (Ft.)
the 'Hazard' location (outside of flare)
"Gating" Terminals typically have a 'Start LON' at Post 3 or Post
4, per the APL Drawings. For "Non‐Gating" Terminals, the 'Start
Length of Gating, LG (Ft.) 12.5 LON' is at 'Post 1' (L G =0).
NOTE: The flare rate effect on L G, assumed parallel to the
roadway, is negligible and may be omitted.
4 Ft. Max. per Index 400 detail, measured offset at Post(1);
Terminal Flare @ Post(1) (Ft.) 4
enter zero for "Parallel" Terminals
default value is acceptable at 35'‐0", but this may be refined
Flare's Taper Length (Ft.) 35
per specific APL drawing (Input used to calculate 'Y')
Output:
End Treatment Offset, Y (Ft.)
Runout Length, LR (Ft.)
Length of Need, X (Ft.) AASHTO RDG (5‐3)
Unadjusted Begin/End Guardrail Sta.
@ Primary Approach Terminal
Unadjusted Begin/End Guardrail Sta.
@ Trailing Anchorage (If Applicable)
* NOTE: If the Trailing Anchorage shown herein is in the
Clear Zone of an opposing Traffic Lane, use an Approach
Terminal in its place.
Input: Comment:
Is this a 2‐lane, 2‐way road with the Hazard in the Far Lane's
PART B Required?
No Clear Zone limit? If "No" Part B will be excluded from the
(User Input Needed)
placement calculation output below.
the lesser distance from the 'Edge of Traffic Lane' (Far Lane) to
Lateral Area Concern, LA (Ft.)
the 'Clear Zone Limit' or 'Back of Hazard'
the typical guardrail offset from the 'Edge of Traffic Lane' (Far
Lateral Offset of Guardrail, LO (Ft.)
Lane), near the 'Hazard' location (outside of flare)
per the APL Drawings, "Gating" Terminals typically have a
'Start LON' at Post 3 or Post 4. For "Non‐Gating" Terminals, the
Length of Gating, LG (Ft.) 12.5 Start LON is at 'Post 1' (L G =0).
NOTE: The flare rate effect on L g , assumed parallel to the
roadway, is negligible and may be omitted.
4 Ft. Max. per Index 400 detail; measured to Post(1); enter
Terminal Flare @ Post(1) (Ft.) 0
zero for 'Parallel' Terminals
default value is acceptable at 35'‐0", but this may be refined
Flare's Taper Length (Ft.) 0
per specific APL drawing (Input used to calculate 'Y')
Output:
End Treatment Offset, Y (Ft.) N.A.
Direction of Far Lane Traffic N.A.
Approach Face of Hazard Station (Far
N.A.
Lane)
Runout Length, LR (Ft.) N.A.
Length of Need, X (Ft.) N.A. AASHTO RDG (5‐3)
Unadjusted Begin/End Guardrail Sta.
N.A.
@ Secondary Approach Terminal
DESIGN OUTPUT SUMMARY: GUARDRAIL ROADSIDE HAZARD SHIELDING
Limit: Output:
Adjusted Begin/End Guardrail Sta.
@ PRIMARY Approach Terminal
(From Part A)
≥
Outputs assume linear stationing:
Guardrail Offset from Nearest Edge of Traffic Lane (Ft.) :
To adjust for curvature, lengthen the
Adjusted Begin/End Guardrail Sta. guardrail with the Begin/End
@ Trailing Anchorage (Type II)
(From Part A, If Applicable)
≤ Guardrail stations placed outside of
the stationing limits shown here. Use
Guardrail Offset from Nearest Edge of Traffic Lane (Ft.) : CADD measurement to bring the
Adjusted Begin/End Guardrail Sta. final guardrail length to a multiple of
6'‐3" panels.
@ SECONDARY Approach Terminal
(From Part B, If Applicable)
‐
Guardrail Offset from Nearest Edge of Traffic Lane (Ft.) :
PART C: CROSSOVER GUARDRAIL WITH 'CRASH CUSHION' ‐
SHIELDING CONCRETE RAILING ACROSS MEDIAN (WITHIN CLEAR ZONE)
Input: Comment:
Direction of Near Lane Traffic Westbound for relative stationing calculations
AADT (Vehicles Per Day)
Design Speed (MPH)
Begin/End Rigid Barrier Sta. enter as total feet (do not input a plus sign); located at the end of
(@ guardrail connecting location) the 'Rigid Barrier' (not the Begin/End Guardrail Sta.)
the starting guardrail offset from the 'Edge of Near Traffic Lane' at
Lateral Offset of Guardrail, LO (Ft.) the location where the guardrail connects to the 'Rigid Barrier'
(determined by the designer)
the lateral distance from the 'Edge of Near Traffic Lane' to the far
Lateral Area Concern, L A (Ft.) edge of the opposing 'Rigid Barrier' (i.e. Concrete Traffic Railing)
across the median
the length of the guardrail Approach Transition Connection prior
to the start of the taper; per Index 400 options,
Parallel Approach Trans. Length, L P1 (Ft.) 27.5 TL‐3=27.5 Ft. and TL‐2=18.2 Ft.
Note: This is measured from the end of the 'Rigid Barrier' (not the
'Begin/End Guardrail Sta.')
the length of the parallel segment required for Guardrail
Parallel C.C. Segment Length, LP2 (Ft.) 21.9 Transition, just beyond the taper. This is the length between Post
(1) and Post (10) per Index 430, 21.9 Ft.
the length between Post (1) and the 'Start LON' (or Departure Line
Design Length of Crash Cushion, L D (Ft.)
intersection) per the manufacturer's APL Drawing
the linear taper rate for the Median Crossover Segment; 1:10 for
Taper Rate of Crossover, 1:TR (Ft.) 15
Design Speeds ≤ 45 MPH and 1:15 for Design Speeds > 45 MPH.
the longitudinal "skew" distance between the guardrail's
connecting Rigid Barrier end and the 'Hazard' Rigid Barrier end
Rigid Barrier Skew, S (Ft.)
(across the median). For the direction opposite the drawing
dimension, use a negative value.
PART C: OUTPUT SUMMARY:
End Treatment Offset, Y (Ft.)
Runout Length, L R (Ft.)
The outputs assume stationing is linear and are adjusted to bring
Length of Need, X S (Ft.) tapered segment panel lengths to a multiple of 6'‐3".
Begin/End Guardrail Sta.
@ Connection to Rigid Barrier The output stations may be used directly in the Plans, assuming
Offset from Edge of Near Traffic Lane (Ft.) that roadway curvature does not cause a discrepancy of more
than 3'‐0" between the these output stations and the actual
Begin/End Taper Sta. guardrail panel slot & post locations (Tolerance per Specification
Offset from Edge of Near Traffic Lane (Ft.) Section 536).
Begin/End Taper Sta. If adjustments for curvature are required to bring the stationing
closer to the actual panel slot & post locations, use L P1 , L P2 , and
Offset from Edge of Near Traffic Lane (Ft.)
L D , adjusted for curvature, and add additional length to the taper
Begin/End Guardrail Sta. segment as needed.
@ Connection Post (1)
Offset from Edge of Near Traffic Lane (Ft.)
PART D: CROSSOVER GUARDRAIL WITH 'APPROACH TERMINAL' ‐
SHIELDING CONCRETE RAILING ACROSS MEDIAN (WITHIN CLEAR ZONE)
Input: Comment:
Direction of Near Lane Traffic Westbound for relative stationing calculations
AADT (Vehicles Per Day)
Design Speed (MPH)
Begin/End Rigid Barrier Sta. enter as total feet (do not input a plus sign); located at the end of
(@ guardrail connecting location) the 'Rigid Barrier' (not the Begin/End Guardrail Sta.)
the starting guardrail offset from the 'Edge of Near Traffic Lane' at
Lateral Offset of Guardrail, LO (Ft.) the location where the guardrail connects to the 'Rigid Barrier'
(determined by the designer)
the lateral distance from the 'Edge of Near Traffic Lane' to the far
Lateral Area Concern, L A (Ft.) edge of the opposing 'Rigid Barrier' (i.e. Concrete Traffic Railing)
across the median
the length of the guardrail Approach Transition Connection prior
to the start of the taper; per Index 400 options,
Parallel Approach Trans. Length, L P1 (Ft.) 27.5 TL‐3=27.5 Ft. and TL‐2=18.2 Ft.
Note: This is measured from the end of the 'Rigid Barrier' (not the
'Begin/End Guardrail Sta.')
the length of the parallel segment required for the Approach
Parallel Approach Terminal Length, L P2 (Ft.) 56.3
Terminal, just beyond the taper; Per Index 400, TL‐3 = 56.3 Ft.
"Gating" Terminals typically have a 'Start LON' at Post 3 or Post 4,
Length of Gating, L G (Ft.) 12.5 per the APL Drawings. For "Non‐Gating" Terminals, the 'Start LON'
is at 'Post 1' (L G =0).
the linear taper rate for the Median Crossover Segment; 1:10 for
Taper Rate of Crossover, 1:TR (Ft.) 15
Design Speeds ≤ 45 MPH and 1:15 for Design Speeds > 45 MPH.
the longitudinal "skew" distance between the guardrail's
connecting Rigid Barrier end and the "Hazard" Rigid Barrier end
Rigid Barrier Skew, S (Ft.)
(across the median). For the direction opposite the drawing
dimension, use a negative value.
PART D: OUTPUT SUMMARY:
End Treatment Offset, Y (Ft.)
Runout Length, L R (Ft.)
The outputs assume stationing is linear and are adjusted to bring
Length of Need, X S (Ft.) tapered segment panel lengths to a multiple of 6'‐3".
Begin/End Guardrail Sta.
@ Connection to Rigid Barrier The stations provided here may be used directly in the Plans,
Offset from Edge of Near Traffic Lane (Ft.) assuming that roadway curvature does not cause a discrepancy of
more than 3'‐0" between the these output stations and the actual
Begin/End Taper Sta. guardrail panel slot/post locations (Tolerance per Specification
Section 536).
Offset from Edge of Near Traffic Lane (Ft.)
Begin/End Taper Sta. If adjustments for curvature are required to bring the stationing
closer to the actual panel slot and post locations, use L P1 and L P2 ,
Offset from Edge of Near Traffic Lane (Ft.)
adjusted for curvature, and add additional length to the taper
Begin/End Guardrail Sta. segment as needed.
@ Post (1)
Offset from Edge of Near Traffic Lane (Ft.)
LP2
Post (1) on
Standard -
Begin
Guardrail
Measurement
(to left)
Begin ‘LON’
LD = Design Length
Length of Need v1.0 - Supplement
DESIGN TOOL PART D, APPROACH TERMINAL
How to find variable LP2:
From Index 400,
Taper Begins Sheet 8…
Here...
Sheet 17…
‘LE’ = 53’-1½”
LP2 = ‘LE’ + ½ Span =
LP2 = (53’-1½” ) + (3’-1½”) =
LP2 = 56’-3”