ABC POLICY DEVELOPMENT
IOWA DOT
Norman McDonald, PE
Iowa Department of Transportation
Office of Bridges and Structures
MID-CONTINENT TRANSPORTATION RESEARCH SYMPOSIUM
STRUCTURES/CONSTRUCTION SESSION 2D
AUGUST 15, 2013
Iowa’s ABC Experience
Develop skills and design details through
demonstration projects
Invest in research with laboratory and field
testing to confirm constructability and
performance.
Participate in national pooled fund studies
Involve local construction industry and hold
ABC workshops.
ABC Policy Development
Goal is to create a statewide policy to
determine when ABC should be used.
Assembled a team of engineers from
Project Delivery Bureau, Districts,
Research, and FHWA along with
representatives from Highway Division
Management Team (HDMT). Also
included industry representatives.
Goal was to have a draft by July 2012
ABC Policy Development
Conducted a survey of State DOTs
Collected and reviewed all available policies
Discussed the development of the policy with
other states, FHWA staff, and national experts
at various conferences and workshops
Collaborated with neighboring states and
hosted a regional policy forum
Visited a State DOT with established
experience in ABC
ABC Policy
The Iowa ABC policy utilizes two
decision making tools :
– ABC Rating Score & Flow Chart similar to
Utah as a first level filter
– AHP Decision Making Tool as a second
level confirmation and further evaluation of
alternatives.
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
ABC Rating Score Concept
Measures
Measures are limited to data that are readily
available in NBI database and can be
programmed to calculate a Rating Score:
Average Annual Daily Traffic (AADT)
Out-of-Distance Travel (miles)
Daily Road User Costs
Economy of Scale (total number of spans)
Average Annual Daily
Traffic (AADT)
Use a value equal to the total number of
vehicles on the bridge plus 25% of the
AADT for any roadways under the bridge.
0 No traffic impacts
1 Less than 5000
2 5000 to less than 10,000
3 10,000 to less than 15,000
4 15,000 to less than 20,000
5 20,000 or more
Out-of Distance Travel
(miles)
This is a measure of the impact that a
project has on vehicles when the
construction site is closed to traffic.
0 No detour
1 Less than 5
2 5 to less than 10
3 10 to less than 15
4 15 to less than 20
5 20 or more
Daily Road User Costs
Is the measure of daily financial impact of a
construction project on the traveling public.
Major contributing factors are out of distance
travel (OOD) and AADT on the bridge.
The standard method used for calculating
user costs is the formula:
DRUC=(AADT+2xADTT)xOODxMileage Rate
The mileage rate is currently set at 37.5 cents
per mile. Truck traffic (ADTT) is counted at
three times the amount of other traffic.
Daily Road User Costs
0
1
2
3
4
5
No user costs
Less than $10,000
$10,000 to less than $50,000
$50,000 to less than $75,000
$75,000 to less than $100,000
$100,000 or more
Economy of Scale
(number of spans)
Accounts for the repetition of elements and
processes, and how they relate to cost, as
well as possible savings to future projects.
Number of spans is used to account for
repetition of substructure elements and
superstructure elements.
0 1 span
1 2 or 3 spans
2 4 or 5 spans
3 6 spans or more
ABC RATING SCORE FACTORS AND
WEIGHTS
Measures
Score Weight
Factor
Weighted Maximum
Score
Score
Weighted
Maximum
Score
Average Annual Daily Traffic
5
10
50
5
50
Out of Distance Travel
2
10
20
5
50
Daily Road User Costs
4
10
40
5
50
Economy of Scale
2
5
10
3
15
Total Score
120
Max Score
165
ABC Rating Score
(Total Score/Max Score)x100= 73
ABC Rating Score Distribution for State Bridge
Replacements in Iowa for 5 year Plan (2013 to 2017)
40
35
35
33
30
0 to < 10
10 to < 20
25
Number of
State Bridge
Replacements
(Total = 120) 20
20 to < 30
22
30 to < 40
40 to < 50
50 to < 60
60 to < 70
15
70 to < 80
11
80 to < 90
10
90 to 100
10
5
4
5
0
0
ABC Rating Score Distribution
0
0
ABC Rating Score Distribution for State Bridges in Iowa
1200
1008
1000
970
800
771
0 to < 10
10 to < 20
20 to < 30
Number of
State Bridges
(Total = 4072)
30 to < 40
40 to < 50
600
50 to < 60
505
60 to < 70
70 to < 80
445
80 to < 90
400
90 to 100
274
200
48
0
ABC Rating Score Distribution
32
12
7
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
First-Stage Decision Making Flowchart
ABC Rating Score
50 to 100
ABC Rating Score
Less than 50
District requests
further review for
ABC?
Yes
Yes
No
Does the project support
an ABC approach based
on OBS, District,Yesand
possibly others’
evaluation?
No
No
No
No
Does the Project
Concept Team want
the project to undergo
further ABC
evaluation?
Yes
Use Traditional Construction
Perform ABC AHP Analysis for
Second-Stage Decision Making
Yes
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
AHP Criteria Organization
19
Criteria
 A decision maker can insert or eliminate
levels and elements as necessary to
sharpen the focus on one or more parts of
the analysis. Less important criteria and
sub-criteria can be dropped from further
consideration.
New Sub-Criteria
AHP Analysis Details
Comparisons between criteria and between
sub-criteria are performed using data from
actual measurements or using a qualitative
scale.
Direct
Costs
Direct
Costs
Direct
Costs
9
8
7
6
5
4
3 2
1
2
3
4
5
6
7
8
9
Indirect
Costs
9
8
7
6
5
4
3 2
1
2
3
4
5
6
7
8
9
Schedule
Constraints
9
8
7
6
5
4
3 2 1
2
3
4
5
6
7
8
9
Site
Constraints
AHP Analysis Details
Comparisons are also used to assess the
extent to which one alternative satisfies a
criteria over another alternative.
Alt A
9
8
7
6
5
4
3 2
1
2
3
4
5
4
5
6
7
8
9
6
7
8
9
Alt B
Direct Costs
Alt A
9
8
7
6
5
4
3 2
1
2
3
Indirect Costs
Alt B
Results
23
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
Calculate ABC Rating Score
No
First-Stage Filter: Use First-Stage
Decision Making Flowchart
Yes
No
Second-Stage Decision Making:
Use the ABC AHP Tool
Yes
No
Project Delivery Concurrence
Yes



Determine Tier of Acceleration
OBS recommends ABC options based on Tier of Acceleration
MDT reviews OBS recommendations
Develop ABC Concept Alternative(s) and Estimate Costs
Develop Traditional
Concept Team
Alternatives and Costs
Recommended Alternatives
Concept Selection and Statewide Prioritization
ABC Decision Process Flowchart
OBS Concerns
Additional duties/assignments within OBS
to perform ABC evaluation (i.e. AHP
analysis)
Additional time required for developing
ABC design concepts
Need to develop ABC design standards
and policies
Need to develop expertise to perform inhouse ABC design or support/guide
consultant design
OBS Concerns
Accuracy of estimating cost for new ABC
concepts.
Unknown long term performance of
bridges constructed with ABC.
Need for higher level of construction
inspection.
ABC Implementation Challenges
Funding to offset ABC construction cost –
need to identify new revenues or alternative
funding
Resistance from some local contractors to
ABC – working with industry to change the
climate
Limited contracting methods – since Design
Build (DB) is not allowed in Iowa we are
looking at the partial DB option
ABC Implementation Challenges
Design aids – we are working on ABC design
policies, specifications and standard details.
Limited experience in ABC design – several
ABC projects have been identified to attain
experience for our engineers.
Questions?
Norm McDonald
Director, Office of Bridges and Structures
Iowa Department of Transportation
Norman.mcdonald@dot.iowa.gov