Milton Madison bridge design project showing fuzzy system model.

1. Milton Madison Bridge
Preference Results
April 2009

2. Executive Summary
On February 12, 2009, approximately 165 citizens of Milton, Kentucky and
Madison, Indiana attended a bridge location and design public meeting held in the
Brown Gymnasium in Madison, Indiana. Included in the attendees was the Public
Advisory Group and the Section 106 Historic Advisory Panel. After other meeting items
were attended to, all participants were invited to view, discuss, and rate the suitability
of a set of 18 bridge design concepts. Their task was to rate each concept for its
suitability in the context of replacement for the existing 1929-era bridge. Meeting
organizers contracted with the U. of Kentucky Transportation Center to provide a
Structured Public Involvement protocol for purposes of identifying the level and type of
preferences of the attendees for various combinations of bridge design properties.
Attendees rated 6 arch designs + 1 truss-arch+ 5 trusses + 6 cable stay
concepts. These concepts varied in their visual complexity, color value (lightness to
darkness), type of enclosure created by the superstructure, and the overall profile of
the structure. This data, together with the preferences gathered from the general
audience and the data gathered from the 106 panel, was modeled, so that designers
could better understand the interplay between cost, constructability, maintenance, and
visual preference by citizens.

3. Executive Summary (2)
A few general observations.
•The average preference scores were highest for cable-stay designs, although the
variability across the participants was the highest. That is to say, all of the cable stay
designs were generally preferred, but none of them, indeed none of the 18
concepts, was a single, clear ‘winner.’
•While the public and Sec. 106 average scores were often significantly different in
value, rarely were they different in direction: Sec. 106 participant scores tended to be
higher and lower than those of the general public.
•Low to moderate complexity + light color arches preferred.
•Twin arches preferred to single.
•Single or twin “H” arches, or twin “A” or “Mod” arches with light color+low complexity
a likely preference.
•Truss concepts were generally not preferred, with the exception of concepts that
mimicked the existing bridge in terms of shape and style.
•Lighter colors preferred for multiple-haunch trusses.
•Twin arches were generally preferred to single, and light arches preferred to dark.
•“A” Shaped cable stays preferred to “Mod” preferred to “H” shapes.
•Light arch colors preferred to darker.
•Cable complexity not a strong influence.

4. Citizen’s Preferences
• Citizens + PAG + “PAG+106”
• Parameters Modeled
– Color Value
– Enclosure Level
– Bridge Structural Type
– Profile
– Visual Complexity

5. Model Coding From FKB
Numeric
Code
250 500 750
Bridge Type Arch Cable Stay Truss
Complexity Low Medium High
Color Value Light Med Dark
Profile 0 1 2+
Enclosure “A” or
Truss
Low
Med “H” or
Truss High

6. Scoring Summary and Standard
Deviation by Groups

7. General Observations
• Highest Averages: Cable Stays
• Lowest Averages: Trusses
• Lower Scores More Uniform (Less Variability)
• 106 Means Have Wider Range than Citizen/PAG
• Statistically Significant Differences between Citizen/PAG
and Sec. 106 on Majority of Samples
• Only Two Samples Differ on Directionality, Rest Differ on
Degree of Preference
• For Modeling Purposes, Scoring Ranges for Each Model
Equalized into 7 Categories: VL, L, Below, OK, Above, H, VH
• Absolute Values for Categories Unique to That Model Due
to Differences in Range

8. Observations About Sample Set
• Some Parameters Tested Unevenly: “Profile”
– CS: Two Towers Only
– Arches: One or Two Arches Only
– Trusses: 0,1,2,3 Haunches
• Slight Uneven Distribution of Types: 7 Arches,
5 Trusses, 6 Cable Stays
• Cable Stay Towers = Light Color Value Only

9. Coding Sheet and Results
Design Citizens and PAG 106 + 106andPAG
Mean Class Mean Class Type Profile ComplexityEnclosure Color
A1 4.65 OK 2.84 L 1 2 3 3 3
A2 4.05 BEL 2.50 VL 1 2 1 3 2
A3 5.36 H 4.16 ABO 1 3 2 3 1
A4 4.46 OK 3.65 OK 1 3 2 2 3
A5 3.67 L 2.74 L 1 2 2 1 2
A6 4.36 BEL 3.20 BEL 1 2 1 1 1
T1 3.77 L 3.20 BEL 1 2 3 3 1
T2 2.52 VL 4.20 ABO 3 2 3 2 2
T3 1.99 VL 2.40 VL 3 1 2 3 3
T4 3.36 L 5.25 VH 3 3 2 1 3
T5 1.59 VL 1.90 VL 3 1 1 3 2
T6 4.90 ABO 6.80 VH 3 3 2 1 1
C1 5.33 H 4.35 ABO 2 3 2 3 3
C2 5.82 VH 4.65 H 2 3 2 1 2
C3 5.50 H 5.00 VH 2 3 1 1 1
C4 6.11 VH 4.65 H 2 3 3 1 1
C5 4.91 ABO 3.75 OK 2 3 1 3 3
C6 6.45 VH 4.95 H 2 3 2 2 1

10. Arch 01
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.65 OK
Sec. 106 2.84 L

11. Arch 02
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.05 BEL
Sec. 106 2.50 VL

12. Arch 03
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
5.36 H
Sec. 106 4.16
ABO
-- It is simple
− Like the color
− It is transparent
− Like the two spans
− It has fewer piers
− Like the historic (arch) and
modern feel
− It is curvilinear and unobstructed
− It fits the space nicely
− It looks low maintenance
− It matches the bicentennial
theme (two arches)

13. Arch 04
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.46 OK
Sec. 106 3.65 OK

14. Arch 05
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
3.67 L
Sec. 106 2.74 L
− It looks insignificant
− There is no inspiration
− It looks disproportionate to the
space
− It is not as clean
− Do not like the darker color
− It is too minimal for the space
(valley)
− It is boring

15. Arch 06
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.36 BEL
Sec. 106 3.20 BEL

16. Truss 01/
Arch07
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
3.77 L
Sec. 106 3.20 BEL

17. Truss 02
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens +
PAG
2.52 VL
Sec. 106 4.20 ABO

18. Truss 03
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
1.99 VL
Sec. 106 2.40 VL

19. Truss 04
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
3.36 L
Sec. 106 5.25 VH

20. Truss 05
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
1.55 VL
Sec. 106 1.90 VL
− It is boring
− It looks like a railroad bridge (bad)
− This could be for the centennial

21. Truss 06
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.90
ABO
Sec. 106 6.80
VH
− Like the light color
− It resembles the current bridge
which is good (2 comments)
− It looks historically appropriate
− Like the design that goes all the way
across the river
− The superstructure may interfere
with the views looking through it
− The shape compliments the hills
− This could be for the “tri-
centennial” (three peaks)
− It looks less expensive with fewer
piers
− Fewer piers mean less obstruction
for river traffic

22. CS 01
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
5.33 H
Sec. 106 4.35 ABO

23. CS 02
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
5.82 VH
Sec. 106 4.65 H

24. CS 03
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
5.50
H
Sec. 106 5.00
VH
− It has good visibility
− It looks fun to drive on
− It does not look stable (not sure
how the cable stays stand up)
− It does not look like an H or a
wishbone (good)
− The median post looks like it
would cause accidents
− This limits your maximum width
with the towers in the median
− Would there be a concrete barrier
at the median along the length of
the bridge?

25. CS 04
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
6.11 VH
Sec. 106 4.65 H

26. CS 05
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
4.91
ABO
Sec. 106 3.75
OK
− The straight piers are appealing
− The dark color may have a negative
influence on the rating of the style
− It looks like rabbit ears
− It is too geometric for the
topography
− The cable-stays emphasize the
future
− The radial cables are better than
the harped (parallel) ones

27. CS 06
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
Citizens
+ PAG
6.45
VH
Sec. 106 4.95
H
− It is very open
− It does not take up the river view
− It looks like it would take less
maintenance
− It is a modern looking bridge (good)
− This would look better outside of
downtown
− Not having structure overhead is a
plus (bird droppings, painting, etc…)
− There is no place for the pigeons
(good)
− It leaves the water more open

28. Pub. Arches: “H” Shape, Two Arch
Light
Dark
Low
HighA3 H

29. 106. Arches: “H” Shape, Two Arch
Light
Dark
Low
HighA3 ABO

30. Pub. Arches: “Mod” Shape, Two Arch
Light
Dark
Low
High
A4 OK

31. 106. Arches: “Mod” Shape, Two Arch
Light
Dark
Low
High
A4 OK

32. Pub. Arches: “A” Shape, Two Arch
Light
Dark
Low
High

33. 106. Arches: “A” Shape, Two Arch
Light
Dark
Low
High

34. Pub. Arches: “A” Shape, One Arch
Light
Dark
Low
High
A5 L
A6 BEL

35. 106. Arches: “A” Shape, One Arch
Light
Dark
Low
High
A5 L
A6 BEL

36. Pub. Arches: “H” Shape, One Arch
Light
Dark
Low
High
T1 L
A1 OK
A2 BEL

37. 106. Arches: “H” Shape, One Arch
Light
Dark
Low
High
T1 BEL
A1 L
A2 VL

38. Arches Summary: Pub and 106
• Twin Arches Generally Preferred Over Singles
• Single or Twin “H” Arches of Light Color and
Low to Moderate Complexity a Possibility
• Twin “A” or “Mod” Arches of Light Color and
Low Complexity a Possibility

39. Pub. Trusses: 2+ Haunches, Low Enclosure (Tall Structure)
Light
Dark
Low
HighT6 ABO
T4 L

40. 106. Trusses: 2+ Haunches, Low Enclosure (Tall Structure)
Light
Dark
Low
HighT6 VH
T4 VH

41. Pub. Trusses: 0 Haunches, High Enclosure (Low Structure)
Light
Dark
Low
High
T5 VL
T3 VL

42. 106. Trusses: 0 Haunches, High Enclosure (Low Structure)
Light
Dark
Low
High
T5 VL
T3 VL

43. Pub. Trusses: 0 Haunches, Low Enclosure (High Structure)
Light
Dark
Low
High

44. 106. Trusses: 0 Haunches, Low Enclosure (High Structure)
Light
Dark
Low
High

45. Pub. Trusses: 1 Haunches, Low Enclosure (High Structure)
Light
Dark
Low
High

46. 106. Trusses: 1 Haunches, Low Enclosure (High Structure)
Light
Dark
Low
High

47. Pub. Trusses: 1 Haunch, High Enclosure (Low Structure)
Light
Dark
Low
High

48. 106. Trusses: 1 Haunch, High Enclosure (Low Structure)
Light
Dark
Low
High

49. Pub. Trusses: Mod. Complex, Low Enclosure (High Structure)
Light
Dark
Low
High

50. 106. Trusses: Mod. Complex, Low Enclosure (High Structure)
Light
Dark
Low
High

51. Trusses Summary: Public and 106
• More Haunches Preferred Generally
• Taller Structures Preferred (Low Enclosure)
• Lighter Color Values Preferred for Multiple
Haunches
• Slight Preference Toward Mod-High
Complexity
• 106 Generally Stronger Preference for
Trusses, More Tolerant of Dark Colors

52. Pub. Cable Stay: 2 Towers, “A” Enclosure
Light
Dark
Low
HighCS4 VH
CS3 H
CS2 VH

53. 106. Cable Stay: 2 Towers, “A” Enclosure
Light
Dark
Low
High
CS4 H
CS3 VH
CS2 H

54. Pub. Cable Stay: 2 Towers, “Mod” Enclosure
Light
Dark
Low
High
CS6 VH

55. 106. Cable Stay: 2 Towers, “Mod” Enclosure
Light
Dark
Low
High
CS6 H

56. Pub. Cable Stay: 2 Towers, “H” Enclosure
Light
Dark
Low
High
CS1 H
CS5 ABO

57. 106. Cable Stay: 2 Towers, “H” Enclosure
Light
Dark
Low
High
CS1 ABO
CS5 OK

58. Cable Stay Summary: Public and 106
• “A” Shapes Generally Preferred to “Mod”
Preferred to “H”
• Light to Moderate Color Values Preferred
• Cable Complexity Generally Unimportant

59. Public Acceptance of Process
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%