Post on 30-Jan-2022
Tracy Borchardt April 2013
Barrier Warrant Process
1
Traffic Barrier Warrants Each roadside barrier and safety appurtenance
installed on the Tollway System needs to be justified and the analysis documented.
2
Traffic Barrier Guidelines
3
• BWA Process
• Usage Guide
March 2013
References
AASHTO Roadside Design Guide, 4th Edition-2011
Clear Zone, Chapter 3
Location of Barriers, Chapter 5
Barrier Length & End Treatment, Chapter 5
Benefit/Cost Analysis
4
POTENTIAL ROADSIDE OBSTACLES
TBG – SECTION 3.0
5
Potential Roadside Obstacles
Design Options:
1. Remove obstacle
2. Relocate obstacle
3. Reduce impact severity.
4. Shield obstacle.
5. Delineate obstacle.
6
Potential Roadside Obstacles
Gutters and Curbs
Embankments
Sign Supports
Bridge Piers, Parapets, Abutments & Bridge Cones
Noise Abatement Wall
Drainage Structures
Ditches
Riprap
Roadway Lighting
ITS Systems
Utility Poles
Trees
Bodies of Water
Rock Cuts
7
Gutters and Curbs
Type C Curb
Type G-3 Modified Gutter
Type G-3 Gutter
8
Type G-3 Gutters
9
Type G-2 Gutters
10
Gutter and Guardrail
G-3 Modified Gutter G-3 Gutter
11
Gutter may be constructed in conjunction with guardrail, but is not required
solely because of the presence of guardrail and vice versa.
Guardrail shall not be constructed to shield improperly placed gutter or curb.
Guardrail
Embankments
Roadside Geometry and Terrain Features ,
Section 5.2.1 of the AASHTO Guide.
12
Comparative Risk Warrants for Embankments (RDG Fig. 5-1b)
13
Sign Supports
Overhead Sign Truss – Cantilever Type
Overhead Sign Truss – Span Type
14
Bridges
Pier
Abutment Cone
Economical bridge designs usually result in the location of bridge piers, abutments, and parapets within mainline or ramp clear zones.
Parapets
15
Noise Abatement Wall
Non-Crashworthy Noise Wall
Crashworthy Noise Wall
16
Drainage Structures
Issues:
•Headwall not flush with embankment
•Pipe too short
•Headwall too close to roadway
•Steep slope just above headwall
•Skew
17
Drainage Structures- Corrected
18
Safety End Treatment
19
Ditches
Drainage Channels, Section 3.2.4 of the AASHTO Guide.
20
Roadway Lighting
21
Roadway Lighting (cont.)
Controllers and Transformers
22
Communication Systems and ITS Devices
NID RWIS CCTV Camera
Non-Breakaway 23
Bodies of Water
Bodies of water greater than 2’ in depth must be shielded.
Locate detention basins well outside the clear zone.
24
BARRIER WARRANT ANALYSIS PROCEDURE
TBG – SECTION 4.0
25
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles
2. Name Obstacles
3. Prepare/Present Exhibit (Concept Meeting)
26
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
27
a. Establish Edge of Traveled Way
EOP 1’ outside of the EOTW
EOTW = EOP
28
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
b. Design Speed (Speed Profile for ramps, etc.)
29
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
b. Design Speed
c. Design ADT
30
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
b. Design Speed
c. Design ADT
d. Length of Runout
31
c. Length of Runout
L2
Figure 5-39. Approach Barrier Layout Variables
LR
32
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
b. Design Speed
c. Design ADT
d. Length of Runout
e. Shy Line Offset
33
d. Shy Line Offset
34
Barrier Warrant Analysis Procedure
1. Identify Potential Obstacles.
2. Name Obstacles.
3. Prepare/Present Exhibit.
4. Each AOC shall be analyzed separately.
a. Establish EOTW
b. Design Speed
c. Design ADT
d. Length of Runout
e. Shy Line Offset
f. Foreslope/Backslope
35
f. Foreslope/Backslope
Foreslope
Backslope
Foreslopes
Within clear zone Elsewhere
1:6 (desirable) 1:4 (desirable)
1:4 (maximum) 1:2.5 (maximum)
Backslopes
1:4 or flatter (desirable)
1:2.5 (maximum)
V1:H1
V2:H2
36
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
37
Clear Zone
The unobstructed, traversable area provided beyond the edge of through traveled way for the recovery of errant vehicles.
38
Clear Zone Distances (Feet) From Edge of Traveled Way (Table 3-1)
Use highest value in range 39
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
40
h. Clear Zone Adjustment
41
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern (LA)
42
i. Lateral Extent of the Area of Concern
L2
Figure 5-39. Approach Barrier Layout Variables
LA
L3
43
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
44
j. Warrant Analysis Level
Decide Warrant Analysis Level
Level 1
Level 2
Level 3
Level 0
Use
Flowchart For Existing
Obstacles
or
Flowchart for Proposed
Obstacles
45
Warrant Analysis Level (Article 5.5)
46
Flowchart for Analysis of Existing Obstacles
47
Flowchart for Analysis of Proposed Obstacles
48
Level 1 Analysis
Level 1 – Existing AOC’s that are traversable elements or can easily be made traversable elements such as:
Existing ground mounted signs, and existing drainage items
Existing ground mounted light poles and electrical handholes
49
Level 1 Analysis
Level 1 – Proposed AOC’s that are traversable elements:
Proposed Ground-Mounted Signs
Proposed light poles
Proposed Drainage Items (culvert and pipe ends 84” or less in vertical opening)
50
Traversable Element
RDG-Figure 4-1. Breakaway Support
Stub Height Measurements
51
4 in.
Traversable Element
4’
1:6
(V:H)
52
Breakaway Sign Supports
An important feature of this breakaway sign system is the ability of its post support to swing up and out of the way when it is struck by an errant vehicle.
53
Safety End Treatment-Steel Grate
Headwall and storm sewer outlets shall be provided with appropriate safety end treatment per Standard Drawings – Section B.
54
Roadway Lighting
Steel Helix Foundation
Needs to be a Traversable
Element
55
Level 2 Analysis
When shielding is required and barrier length of need must be determined.
Cantilever sign post
56
Level 2 Analysis
This analysis is performed for:
EXISTING/PROPOSED OBSTACLES when there are no feasible alternatives for eliminating, or reducing the impact severity of the obstacle.
PROPOSED OBSTACLES for an Alternative in a Level 3 Analysis. The length of barrier and type of terminals has to be determined for each Alternative that involves shielding of the obstacle.
57
Level 3 Analysis
The evaluation of 2 or more possible alternatives for eliminating or reducing the obstacle.
Only consider alternatives that are feasible.
Cannot analyze an alternative that leaves an obstacle unshielded in the clear zone.
This is part of the design process
58
Roadside Safety Analysis Program (RSAP)
http://rsap.roadsafellc.com/
59
Level 3 Analysis
Overhead sign to span roadway with barrier
Overhead sign to span beyond clear zone with no barrier
60
This is most
common Level 3
obstacle
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier (L2)
61
k. Lateral Offset of Barrier
L2
Figure 5-39. Approach Barrier Layout Variables
L2
62
k. Lateral Offset of Barrier
2’- 2 ¾” With Type G-3 Gutter
63
k. Lateral Offset of Barrier 1’-0” Without Gutter
Barrier Warrant Analysis Procedure (cont.)
g. Foreslope/Backslope
h. Clear Zone
i. Clear Zone Adjustment
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
65
l. Upstream End of Guardrail
L2
Figure 5-39. Approach Barrier Layout Variables
Point of Need
66
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
m. Upstream End of Barrier Wall
67
m. Upstream End of Barrier Wall
A = Suggested maximum flare rate for rigid barrier system.
B = Suggested maximum flare rate for semi-rigid barrier system.
68
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
m. Upstream End of Barrier Wall
n. Downstream Terminal
69
n. Downstream Terminal
Traffic Barrier Terminal Type T2
Traffic Barrier Terminal Type T6
70
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
m. Upstream End of Barrier Wall
n. Downstream Terminal
o. Barrier Obstacle
71
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
m. Upstream End of Barrier Wall
n. Downstream Terminal
o. Barrier Obstacle
p. Compare existing length to proposed
72
Barrier Warrant Analysis Procedure (cont.)
g. Clear Zone
h. Clear Zone Adjustment
i. Lateral Extent of the Area of Concern
j. Warrant Analysis Level
k. Lateral Offset of Barrier
l. Upstream End of Guardrail
m. Upstream End of Barrier Wall
n. Downstream Terminal
o. Barrier Obstacle
p. Compare existing length to proposed
q. Prepare warrant text and exhibits
73
PRESENTATION OF BARRIER WARRANT
ANALYSIS TBG – SECTION 6.0
74
Presentation of Barrier Warrant Analyses
Samples
Speed Profile
Location Plan
Level 1 Table
Data Sheet
Calculation sheet
Site Plan
RSAP Feature Sketch
Level 0 Table
75
Presentation of Barrier Warrant Analysis
Checklists
Cover Sheet
Table of Contents
Disposition
Location Plan
Data Sheet
Calculation Sheet
Site Plan
Summary Site Plan
Cross Sections
Level 0 Table
Level 1 Analysis
Level 2 Analysis
Level 3 Analysis
76
BARRIER WARRANT SUBMITTAL SCHEDULE
TBG – SECTION 7.0
77
Submittal Schedule
Barrier Warrant Analysis is part of the Design Process.
Barrier Warrants are not considered final until there are no further review comments on the final submittal.
78
Concept Meeting
The general goals of the meeting are to:
Provide an overview of the project limits, scope of work, and any omissions
Summarize the overall project schedule
Discuss potential AOC’s and barrier warrant analysis methodology
Present unique project issues
Identify locations that are good candidates to be included in the preliminary submittal.
79
Preliminary Submittal Barrier Warrant Analysis shall be submitted with
the Preliminary Plans.
Submit a minimum of five sample locations
At least two Level 2
At least two Level 3 with RSAP output and feature sketch
It is recommended that Designer choose locations that may require more review cycles, are more complex or require extra coordination.
Submit one page of the Level 1 Table (at least 4 AOC’s)
Submit Completed Checklist.
80
Pre-Final Submittal Barrier Warrant Analysis shall be submitted with
the Pre-Final Plans.
Similar to Pre-Final Plans, the Pre-Final Barrier Warrant shall be considered 100% complete.
All comments on preliminary submittal addressed and a disposition provided.
Submit completed checklist.
All above materials shall be submitted through the Tollway’s web-based project management system and in hard copy format.
81
Final Submittal
DSE Final Barrier Warrant shall match the DSE plans submitted for advertisement.
Final Barrier Warrant Analysis should be complete at the Final Plan Check.
All previous review comments addressed and a disposition provided.
Submit completed checklist.
82
Barrier Warrant Amendment Process
83
What
initiated
change to
design?
Who
initiated
change?
Who
completes
Amendment
to BWA?
In addition to
GEC, who
reviews BWA
Amendment?
Field
change
CM or
Contractor DSE CM
Field Change
Barrier Warrant Amendment Process
84
What
initiated
change to
design?
Who
initiated
change?
Who
completes
Amendment
to BWA?
In addition to
GEC, who
reviews BWA
Amendment?
Value
Engineering
Proposal
Contractor Contractor’s
Designer DSE & CM
Value Engineering Proposal
Barrier Warrant Amendment Process
85
What
initiated
change to
design?
Who
initiated
change?
Who
completes
Amendment
to BWA?
In addition to
GEC, who
reviews BWA
Amendment?
Performance
Based
Design
Contractor Contractor’s
Designer DSE & CM
Performance Based Design
Record
Drawings
Field
Conditions
Final Amended
Barrier Warrant
3 Components must be equal
=
=
86
Closing Remarks
Fill out the comment sheet
Take PDH forms
Contact any of the presenters with questions
PowerPoint presentations will be posted to the Tollway website after the 3rd session