A performance audit of the Arizona Department of Transportation design and materials specifications

              STATE OF ARIZONA
OFFICE OF THE
AUDITOR GENERAL
A PERFORMANCE AUDIT
OF THE
L ARIZONA DEPARTMENT OF TRANSPORTATION
DESIGN AND MATERIALS SPECIFICATIONS
MARCH 1983
A REPORTTOTHE
ARIZONA STATE LEGISLATURE
REPORT 83- 4
DOUGLAS R. NORTON. CPA
AUDITOR GENERAL
STATE OF ARIZONA
OFFICE OF THE
AUDITOR GENERAL
March 31, 1983
Members of the Arizona L e g i s l a t u r e
The Honorable Bruce Babbitt, Governor
M r . William A. Ordway, Director
Arizona Department of Transportation
Transmitted herewith is a report of the Auditor General, A Performance
Audit of the Arizona Department of Transportation, Design and Materials
Specifications. This report is the last i n a s e r i e s of seven r e p o r t s
issued on the Arizona Department of Transportation and is i n response t o
Senate B i l l 1001 enacted by t h e T h i r t y - f i f t h L e g i s l a t u r e , Second Special
Session i n 1981.
The blue pages represent a summary of t h e r e p o r t ; a response from the
Arizona Department of Transportation is found on the yellow pages.
My s t a f f and I w i l l be pleased t o discuss or c l a r i f y items i n the r e p o r t .
Respectfully submitted,
w Douglas R. Norton
Auditor General
Enclosure
OFFICE OF THE AUDITOR GENERAL
A PERFORMANCE AUDIT OF THE
ARIZONA DEPARTMENT OF TRANSPORTATION
DESIGN AND MATERIALS SPECIFICATIONS
A REPORT TO THE
ARIZONA STATE LEGISLATURE
REPORT 83- 4
TABLE OF CONTENTS
S UPfARY
INTRODUCTION AND BACKGROUND
SWlARY OF THE CONSULTANT'S REPORT
WRITTEN RESPONSE TO THE AUDITOR GENERAL ' S REPORT
- Page
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3
15
SUMMARY
The Office of the Auditor General has conducted a performance audit of the
Arizona Department of Transportation ( ADOT) Design and Materials
Specifications i n response t o Senate B i l l 1001 enacted by t h e T h i r t y - f i f t h
Legislature, Second Special Session i n 1981. This is the f i n a l audit i n a
s e r i e s of seven audits to be completed on the Arizona Department of
Transportation.
Highway construction is a major expense of S t a t e government involving
approximately $ 200 million of State and Federal funds annually. Highway
construction is also an area which has recently been subject t o
simultaneous escalations i n costs and decreases i n revenues during a t i m e
of increasing demand. Theref ore, maximizing the uses of highway
construction d o l l a r s may now be more c r i t i c a l than ever before.
Currently, one area being examined nationally is achieving cost savings
( while maintaining or improving s a f e t y and s e r v i c e a b i l i t y ) through changes
i n design and m a t e r i a l s s p e c i f i c a t i o n s . Generally t h i s involves small
design changes or modifications f o r specific types of roadways or highway
s i t e s . However, because of the magnitude of the d o l l a r s involved i n
highway construction, even small changes can produce s i g n i f i c a n t savings.
Six previous performance a u d i t s of ADOT focused on administrative and
management aspects of ADOT. Because of the t e c h n i c a l n a t u r e of the
subject, the issue of p o t e n t i a l savings through changes i n design and
m a t e r i a l s s p e c i f i c a t i o n s was not previously addressed. To address t h i s
area we contracted with the Texas Transportation I n s t i t u t e ( TTI).*
* The Texas Transportation I n s t i t u t e was selected following competitive
bidding which a t t r a c t e d nine proposals from leading engineering and
design consulting firms throughout the nation. The proposals were
evaluated by the Office of the Auditor General with the assistance of
D r . Rudy Jiminez of the University of Arizona who is himself a
nationally recognized highway engineering expert.
TTI conducted a thorough review of AUOT's standards and s p e c i f i c a t i o n s and
compared them t o 1) s p e c i f i c a t i o n s recommended by the American
Association of S t a t e Highway and Transportation O f f i c i a l s ( AASHTO),
2) the r e s u l t s of the most current research on highway design and s a f e t y ,
and 3) p r a c t i c e s being used by t h e o t h e r s t a t e s t o reduce c o s t s . This
review lead TTI t o conclude t h a t ". . . ADOT is one of the leading
t r a n s p o r t a t i o n agencies i n this country." This conclusion
notwithstanding, however, TTI recommended changes be made i n ADOT's
s p e c i f i c a t i o n s t o 1) produce s i g n i f i c a n t cost savings 2) improve the
s a f e t y of Arizona's highways, and 3) improve the procedures used by
ADOT. In a d d i t i o n , TTI found t h a t r e v i s i o n s are needed i n Arizona's t o r t
l i a b i l i t y law as it p e r t a i n s t o highway engineering.
P o t e n t i a l Cost Savings
TTI i d e n t i f i e s more than $ 26 m i l l i o n i n p o t e n t i a l cost savings over the
next f i v e years through changes i n three areas: geometric design, value
engineering and roadside management. I n a d d i t i o n , TTI noted a number of
changes which may produce p o t e n t i a l savings, but t o which it did not
p r o j e c t d o l l a r amounts.
TTI estimates t h a t a s much a s $ 13 m i l l i o n can be saved over the
next f i v e years through changes i n geometric design. TTI found
geometric design changes-- which involve such f a c t o r s as lane
widths, shoulder widths and s i d e slopes-- may be appropriate f o r
low- volume roads where no measureable s a f e t y problems have been
found.
TTI estimates t h a t from $ 10 t o $ 13 m i l l i o n can be saved over the
next f i v e years by implementing an a c t i v e value engineering ( VE)
program. Value engineering is the systematic review of
engineering design procedures and p o l i c i e s i n order t o reduce
cost. This review can be performed by both the department and by
c o n t r a c t o r s who a r e then allowed t o r e t a i n a percentage of the
savings. TTI found t h a t other s t a t e s report considerable savings
through the use of value engineering.
TTI estimates t h a t $ 644,000 can be saved over the next f i v e years
through changes i n such areas a s s i g n a l s and l i g h t i n g , signing
and marking, roadside b a r r i e r s , drainage and landscaping.
Safety .
In a d d i t i o n t o p o t e n t i a l c o s t savings, the review i d e n t i f i e d three design
m changes which should be made t o increase the s a f e t y of the Arizona
motorist and reduce p o t e n t i a l l i a b i l i t y t o the S t a t e . These three changes
r e l a t e t o crash b a r r i e r s , sign supports and the manner i n which g u a r d r a i l s
are anchored t o bridges. In each of these areas TTI found design f e a t u r e s
which are not i n compliance with national s a f e t y standards.
Imvroved Procedures
In addition t o the recommendations f o r achieving cost savings and
eliminating p o t e n t i a l s a f e t y problems, TTI a l s o developed numerous
recommendations f o r improving t e c h n i c a l procedures followed by ADOT.
While some of these recommendations may u l t i m a t e l y t r a n s l a t e i n t o cost
savings through improved r e s u l t s , no attempt was made t o quantify such
possible savings . Among the areas addressed i n these recommendat ions a r e
materials t e s t i n g , compaction s p e c i f i c a t i o n s , pavement design procedures
and methods used t o s e l e c t p r o j e c t s .
Tort L i a b i l i t y
TTI found t h a t i n Arizona
" The l i a b i l i t y f o r t o r t s r e l a t e d t o highway d e f e c t s has
gradually been s h i f t e d from no l i a b i l i t y t o absolute
l i a b i l i t y over the past twenty years."
This s h i f t i n l i a b i l i t y has a l s o been accompanied by increasing d o l l a r
l o s s e s and increasing numbers of claims. TTI addressed s e v e r a l concerns
r e l a t i n g t o l i a b i l i t y from an engineering perspective including:
Keeping a l l highway hardware up t o the l a t e s t standard,
Unknown highway d e f e c t s ,
Control of access t o the highway, and
Length of time t o f i l e a claim.
IIGTRODUC TION AND EACKGROUND
The Office of the Auditor General has conducted a performance audit of the
Arizona Department of Transportation ( ADOT) Design and Materials
S p e c i f i c a t i o n s i n response t o Senate B i l l 1001 enacted by t h e T h i r t y - f i f t h
L e g i s l a t u r e , Second Special Session i n 1981. This is the f i n a l a u d i t i n a
s e r i e s of seven a u d i t s completed on the Arizona Department of
Transportation.
Highway c o n s t r u c t i o n is a major expense of S t a t e government involving
approximately $ 200 m i l l i o n of S t a t e and Federal funds annually. Highway
c o n s t r u c t i o n is a l s o an area which has r e c e n t l y been s u b j e c t to
simultaneous e s c a l a t i o n s i n c o s t s and decreases i n revenues during a time
of increasing demand. Therefore, maximizing the uses of highway
c o n s t r u c t i o n d o l l a r s may now be more c r i t i c a l than ever before.
Currently, there is much d i s c u s s i o n n a t i o n a l l y regarding maximizing the
uses of highway c o n s t r u c t i o n d o l l a r s . One area being examined is
achieving cost savings ( while maintaining or improving s a f e t y and
s e r v i c e a b i l i t y ) through changes i n design and m a t e r i a l s s p e c i f i c a t i o n s .
Generally t h i s involves small design changes o r modifications f o r s p e c i f i c
types of roadways o r highway s i t e s . However, because of the magnitude of
@' the d o l l a r s involved i n highway construction, even these small changes can
produce s i g n i f i c a n t savings. For example, changes r e s u l t i n g i n a 1
percent reduction i n t h e o v e r a l l c o s t s of Arizona's highway c o n s t r u c t i o n
represent a p o t e n t i a l of $ 2 m i l l i o n i n annual savings.
a
Six previous performance a u d i t s of ADOT focused on a d m i n i s t r a t i v e and
management a s p e c t s of ADOT. Because of t h e t e c h n i c a l nature of the subject,
the i s s u e of p o t e n t i a l savings through changes i n design and m a t e r i a l s
s p e c i f i c a t i o n s was not previously addressed. To address t h i s area we
contracted with the Texas Transportation I n s t i t u t e ( TTI).*
TTI conducted a thorough review of ADOT's standards and s p e c i f i c a t i o n s and
compared them t o 1) s p e c i f i c a t i o n s recommended by the American Association of
S t a t e Eighway and Transportation O f f i c i a l s ( AASHTO), 2) the r e s u l t s of the
most current research on highway design and s a f e t y , and 3) p r a c t i c e s being
used by the other s t a t e s t o reduce c o s t s . This review lead TTI t o conclude
t h a t ". . . ADOT is one of t h e l e a d i n g t r a n s p o r t a t i o n agencies i n t h i s
country." This conclusion notwithstanding, however, TTI recommended changes
be made i n ADOT's s p e c i f i c a t i o n s t o 1) produce s i g n i f i c a n t cost savings 2)
improve t h e s a f e t y of Arizona's highways, and 3) improve the procedures used
by ADOT .
The f i n a l r e p o r t s u b n i t t e d by TTI contains 223 pages of t e x t and more than 300
pages of t e c h n i c a l appendices. Because of its length and t e c h n i c a l n a t u r e t h e
f u l l report is not being transmitted. I n s t e a d , a summary of the major
elementa of the TTI report forms the substance of t h i s r e p o r t . However, ADOT
has been furnished f u l l copies of the report and a d d i t i o n a l copies of the f u l l
report a r e a v a i l a b l e f o r i n s p e c t i o n by i n t e r e s t e d p a r t i e s a t the Office of the
Auditor General.
The Auditor General and s t a f f express a p p r e c i a t i o n t o the Texas Transportation
I n s t i t u t e f o r the consulting work performed. We a l s o express a p p r e c i a t i o n t o
t h e D i r e c t o r of the Department of Transportation and h i s s t a f f f o r t h e i r
cooperation and a s s i s t a n c e during t h i s a u d i t .
* The Texas Transportation I n s t i t u t e was s e l e c t e d following competitive
bidding which a t t r a c t e d n i n e p r o p o s a l s from leading engineering and
design consulting firms throughout the nation. The proposals were
evaluated by the Office of the Auditor General with the a s s i s t a n c e of
D r . Rudy Jiminez of t h e U n i v e r s i t y of Arizona who is himself a
n a t i o n a l l y recognized highway engineering expert.
SUMMARY OF THE CONSULTANT'S REPORT
The Texas Transportation I n s t i t u t e ( TTI) report on ADOT- Design and
Materials S p e c i f i c a t i o n s is a comprehensive review addressing seven major
areas. * The t h r u s t of t h e i r f i n d i n g s , however, can be categorized i n t o
three general topics:
P o t e n t i a l c o s t savings,
Increased s a f e t y , and
Improved procedures.
I n the course of the work, TTI a l s o reviewed w h a t it perceives t o be a
serious problem with the S t a t e ' s t o r t l i a b i l i t y law a s it p e r t a i n s t o
highway design and engineering.
Despite the many recommendations f o r changes, TTI was generally
complimentary of ADOT a s being ". . . a very progressive department" and
". . . one of the leading t r a n s p o r t a t i o n agencies i n t h i s country."
P o t e n t i a l Cost Savings
TTI i d e n t i f i e s more than $ 26 m i l l i o n i n p o t e n t i a l c o s t savings through
changes i n three areas: geometric design, value engineering and roadside
management. I n a d d i t i o n , TTI noted a number of changes which may produce
p o t e n t i a l savings, but t o which it did not project d o l l a r amounts.
Geometric Design - TTI estimates t h a t a s much as $ 13 m i l l i o n can be saved
over the next f i v e years through changes i n geometric design.
* These area- s are 1) geometric design, 2) m a t e r i a l s , 3 ) pavement design,
4) pavement management system, 5 ) project s e l e c t i o n and
p r i o r i t i z a t i o n , 6) value engineering, and 7) roadside management.
TTI found geometric design changes-- which involve such f a c t o r s a s lane
widths, shoulder widths and s i d e slopes-- may be a p p r o p r i a t e f o r low- volume
roads where no measureable s a f e t y problems have been found. TTI
recommendations included c o n s i d e r a t i o n of 11- foot r a t h e r than 12- foot
minimum lane widths, reducing the width of the paved p o r t i o n of shoulders
and using s t e e p e r s i d e slopes. TTI a l s o suggests increased use of truck
lanes i n l i e u of upgrading completely a two- lane highway t o four lanes
and, when p o s s i b l e , painting l a n e edge s t r i p i n g s i x inches t o one foot
i n s i d e the edge of the highways with unpaved shoulders t o minimize damage
t o the edges of the pavement.
Value Engineering - TTI estimates t h a t from $ 10 t o $ 13 m i l l i o n can be
saved over the next f i v e years by implementing a n a c t i v e value engineering
( VE) program. Although ADOT c u r r e n t l y has a VE s t a f f member, TTI found
t h a t Arizona is f o r f e i t i n g p o t e n t i a l savings because it has no a c t i v e ,
ongoing VE program.
Value engineering is the systematic review of engineering design
procedures and p o l i c i e s i n order t o reduce c o s t . This review can be
performed by both the department and by c o n t r a c t o r s who are then allowed
t o r e t a i n a percentage of the savings. TTI found t h a t VE is most
e f f e c t i v e when applied t o standards and s p e c i f i c a t i o n s a t the
preconstruction stage but can s t i l l save money a t the c o n s t r u c t i o n stage.
Other s t a t e s ' experiences show value engineering is p a r t i c u l a r l y
a p p l i c a b l e t o p r o j e c t s which have:
Costs t h a t s u b s t a n t i a l l y exceed the i n i t i a l e s t i m a t e s ,
Complex design f e a t u r e s ,
D i f f i c u l t o r unusual c o n s t r u c t i o n procedures,
R e l a t i v e l y expensive m a t e r i a l s , and
High maintenance c o s t s over t h e i r s e r v i c e l i v e s .
Other s t a t e s r e p o r t c o n s i d e r a b l e savings through t h e u s e of VE. The most
extensive and best documented use of value engineering is done by
Pennsylvania. Pennsylvania estimates t h a t it generates $ 100 i n savings
for each d o l l a r invested i n value engineering. F u r t h e r , Pennsylvania
found t h a t it saved 5 percent of o r i g i n a l project c o s t s during 1980- 82.
If Arizona were t o o b t a i n a s i m i l a r percentage of savings TTI estimates
the p o t e n t i a l savings over the next f i v e years could be a s much a s $ 50
@ million.
Currently, ADOT has no ongoing value engineering program. Although one
s t a f f member i s assigned t o t h e f u n c t i o n , he is performing o t h e r d u t i e s .
TTI recommends the formation of a functioning VE group and, i f necessary,
the use of o u t s i d e c o n s u l t a n t s t o a s s i s t i n t h i s task. TTI a l s o
recommends t h a t t h e L e g i s l a t u r e i n s i s t on value engineering and provide
a d d i t i o n a l resources, i f necessary, t o achieve the p o t e n t i a l savings.
Roadside Management - TTI estimates t h a t $ 644,000 can be saved through
changes i n roadside management. Further, t h i s is a net savings a s TTI
recommends, f o r s a f e t y reasons, some design changes which would a c t u a l l y
increase sone c o s t s .
Roadside management encompasses such areas as s i g n a l s and l i g h t i n g ,
signing and marking, roadside b a r r i e r s , drainage and landscaping. TTI's
review of these a r e a s l e a d s it t o project the following p o t e n t i a l savings
over the next f i v e years.
TABLE 1
AREAS FOR POTENTIAL SAVINGS I N ROADSIDE MANAGEMENT
Area
P o t e n t i a l Savings
Dollars
E l e c t r i c a l Surge P r o t e c t i o n NIL*
Use of Span Wire Nounted Signal When Feasible $ 25,000
Increasing the L a t e r a l Placement of Certain Signs 50,000
Using High Performance Sheeting i n Lieu of Lighting
on Overhead Signs i n Rural Areas 85,000
Redesign of I n e r t i a Crash Cushions for the Smaller Vehicle** ( 17,000)
Replacement of S l i p Base Breakaway Sign Supports
by a More Economical Frangible Breakaway System NIL
Changing the Policy of Only Buying Two- Pound- Per- Foot
Mild S t e e l Sign Supports N I L
Redesign of Roadside Dykes t o be Safer NIL
Elimination of the Flared Terminal W- Beam End Section 100,000
End Anchorages of W- Beam a t Bridges*" NIL
S l i p Formed Concrete Pledian B a r r i e r Design 180,000
Glare Screen Used on Concrete Median Barrier NIL
Revision of Breakaway Cable Terminal Standards*" ( 4,000)
Redesign of Culvert and Pipe Headwalls i n Lieu of B a r r i e r 125,000
Roadside Mowing, Vegetation Control and Snow Removal 100,000
I r r i g a t i o n Water Monitoring on Use of Drip I r r i g a t i o n NIL
Downscoping Roadside Development Standards
i n Urban AreasICaretaker f o r Roadside Rest Areas NIL
Roadside Development Section S t a f f i n g With S p e c i a l i s t s NIL
FIVE- YEAR PLAN TOTAL = $ 6 44,000
* NIL = l e s s than $ 500 savings per year
The bulk of t h e savings is on one item, s l i p formed concrete median
b a r r i e r , which is f a r overdesigned i n the opinion of the research team.
** Recommended f o r s a f e t y reasons
Other P o t e n t i a l Cost Savings - TTI developed other recommendations f o r
p o t e n t i a l cost savings but did not attempt t o quantify the p o t e n t i a l
d o l l a r amounts. Included among these recommendations were the following
ones:
Allow the use of uncrushed gravel on n o n c r i t i c a l p a r t s of the
pavement on a project- by- project b a s i s . Where s u f f i c i e n t t e s t i n g
shows t h a t performance w i l l not be s a c r i f i c e d , t h i s could c r e a t e
s u b s t a n t i a l savings i n a few p r o j e c t s by allowing t h e use o f
l o c a l l y a v a i l a b l e m a t e r i a l s .
Use a l e s s r e s t r i c t i v e requirement f o r stopping paving work due
t o ambient temperature. Currently ADOT r e q u i r e s c e s s a t i o n a t
45OF; however, more northern s t a t e s use l e s s r e s t r i c t i v e
requirements depending upon the nature of the job.
Safety
In a d d i t i o n t o p o t e n t i a l c o s t savings, the review i d e n t i f i e d three design
changes which should be made t o increase the s a f e t y of the Arizona
motorist and reduce p o t e n t i a l l i a b i l i t y t o the S t a t e . These t h r e e changes
r e l a t e t o crash b a r r i e r s , sign supports and the manner i n which g u a r d r a i l s
are anchored t o bridges.
Crash B a r r i e r s - ADOT's crash b a r r i e r s a r e " very advanced with regard t o
the state- of- the- art" with one small but s i g n i f i c a n t exception. They do
not meet d e c e l e r a t i o n standards f o r vehicles weighing 2,250 pounds o r
l e s s . TTI reported
" An i n j u r y t o the occupant of a vehicle weighing 2250
pounds o r l e s s which impacted an i n e r t i a b a r r i e r would
be most d i f f i c u l t t o defend i n court since the design
is o u t s i d e t h e accepted standard f o r more than f i v e
years . "
TTI reconunends t h a t ADOT review and update the design o f the i n e r t i a
b a r r i e r s t o comply w i t h t h e AASEITO standards.
Sign Supports - TTI found the type of s t e e l used by ADOT f o r sign supports
was leading i n d i r e c t l y t o p o t e n t i a l s a f e t y problems.
To save c o s t s ADOT buys mild s t e e l s i g n p o s t s t o allow s t r a i g h t e n i n g and
reusing bent posts. However, the sign posts do not have s u f f i c i e n t
s t r e n g t h t o support some of the l a r g e r s i g n s . When more support is
needed, f i e l d personnel use m u l t i p l e p o s t s . These a d d i t i o n a l posts
i n c r e a s e t h e momentum change t h a t occurs i f a car s t r i k e s the sign. TTI
noted ADOT signs which had momentum change values were from 330 t o 550
percent g r e a t e r than allowable standards and from 500 t o 845 percent
g r e a t e r than d e s i r a b l e standards.
The consequences of these increased momentum change values are very
s e r i o u s . TTI reported t h a t i f c a r s h i t some of these signs ". . . t h e
d r i v e r and occupants w i l l be k i l l e d on impact." F u r t h e r , where ADOT's
signs do not comply with Federal policy, TTI believes t h a t persons injured
by a c a r h i t t i n g these signs
". . . would have an overwhelming l e g a l b a s i s for a
t o r t claim against the S t a t e of Arizona." ( emphasis
added)
TTI s t a t e d t h a t ADOT could both make the signs s a f e r and save a
" s u b s t a n t i a l amount" of money by using more modern designs f o r sign
supports .
Guardrail Anchorage - TTI found t h e s p e c i f i c a t i o n s f o r anchoring the ends
of g u a r d r a i l s t o bridges did not meet c u r r e n t n a t i o n a l s a f e t y standards.
TTI f e l t the current design could allow ". . . an impacting v e h i c l e t o
p a r t i a l l y snag on the concrete end and be dramatically r e d i r e c t e d i n the
r a i l on t h e o p p o s i t e s i d e of the roadway."
TTI recommends design changes t o c o r r e c t the problem.
Improved Procedures
In a d d i t i o n t o the recommendations f o r achieving cost savings and
e l i m i n a t i n g p o t e n t i a l s a f e t y problems, TTI a l s o developed numerous
recommendations f o r improving t e c h n i c a l procedures followed by ADOT.
While some of these recommendations may u l t i m a t e l y t r a n s l a t e i n t o cost
savings through improved r e s u l t s , no attempt was made t o quantify such
possible savings. Among the areas addressed i n these recommendations are
m a t e r i a l s t e s t i n g , compaction s p e c i f i c a t i o n s , pavement design procedures
and methods used t o s e l e c t p r o j e c t s .
Materials Testing - TTI recommended two changes i n m a t e r i a l s t e s t i n g t o
b e t t e r evaluate m a t e r i a l s s u s c e p t i b l e t o moisture damage and t o improve
t h e e v a l u a t i o n of m a t e r i a l s compaction.
TTI found t h a t moisture damage is believed t o have caused ( o r is a t l e a s t
r e l a t e d ) t o some of the pavement f a i l u r e s i n Arizona. TTI recommended
t h a t ADOT adopt on an experimental b a s i s a more r e l i a b l e t e s t f o r moisture
s u s c e p t i b i l i t y ( the Lottman ~ r o c e d u r e ) which is c u r r e n t l y being used by
other s t a t e s . TTI s t a t e d t h a t
" It would take very few p r o j e c t s i d e n t i f i e d a s being
s u s c e p t i b l e t o moisture damage t o j u s t i f y the use of
t h i s procedure over t h e c u r r e n t method. For example,
i f a n a d d i t i o n a l overlay p r o j e c t was i d e n t i f i e d i n the
5- year program a s being moisture s e n s i t i v e r e q u i r i n g
the use of l i m e or cement, it is estimated t h a t a
savings of approximately $ 20,000 per c e n t e r l i n e mile of
maintenance c o s t ( s e a l c o a t s ) would r e s u l t within the
f i r s t f i v e years of performance."
TTI a l s o recommended a new method f o r compacting l a b o r a t o r y samples of
m a t e r i a l s which produces r e s u l t s more r e p r e s e n t a t i v e of t h a t achieved by
the a c t u a l pavement.
Compaction S p e c i f i c a t i o n s - TTI found t h a t ADOT's s p e c i f i c a t i o n s
adequately address undercompaction ( t o o l i t t l e ) but may allow f o r
overcompaction ( too much) t o occur. This has important engineering
implications a s the s t r e n g t h and d u r a b i l i t y of pavements a r e d i r e c t l y
a f f e c t e d by the amount of compaction. Too l i t t l e - or too much compaction
can severely weaken a pavement.
TTI recommends t h a t ADOT consider r e v i s i n g t h e i r s p e c i f i c a t i o n s t o provide
an upper l i m i t on the acceptable degree of compaction. Even i f an upper
l i m i t is not developed, TTI recommends current s p e c i f i c a t i o n s be modified
t o encourage compaction t o t h e d e s i r e d amount, but not beyond.
Change t o Mechanistic Design Procedures - TTI recommends t h a t ADOT begin a
t r a n s i t i o n from " f l e x i b l e " t o " mechanistic" pavement design procedures.
ADOT c u r r e n t l y uses the " f l e x i b l e " design procedure which focuses on the
performance of t h e c r o s s - s e c t i o n of the highway. However, f r e q u e n t l y
there a r e f a c t o r s which cause surface problems ( such a s cracking) t o
develop, but which do not a f f e c t the remainder of t h e c r o s s s e c t i o n of the
highway. TTI recommends t h a t ADOT begin using the " mechanistic" design
procedure which focuses more heavily on the f a c t o r s which a f f e c t surface
q u a l i t y .
TTI noted the following a s p e c t s of mechanistic design:
1. The general trend n a t i o n a l l y is toward a mechanistic procedure.
2. Mechanistic design procedures a r e based on c r i t e r i a ( f o r example, •
surface q u a l i t y ) which a r e used t o t r i g g e r maintenance
a c t i v i t i e s . Therefore, these procedures would complement ADOT1s
e x i s t i n g pavement management and maintenance programs.
3. Mechanistic design appears t o provide pavement thicknesses which
a r e about the same as the ADOT procedure except on weak s o i l s
where surface f a i l u r e , the c r i t e r i o n of the mechanistic design,
would be g r e a t e r . Therefore, c o s t s should be s i m i l a r except
where j u s t i f i e d by t h r e a t s t o surface q u a l i t y .
According t o TTI, mechanistic design w i l l help prevent overdesign or
underdesign of pavements and w i l l generally r e s u l t i n a more c o n s i s t e n t
pavement l i f e from highway t o highway.
Optimizing P r o j e c t S e l e c t i o n - To improve procedures f o r s e l e c t i n g highway
p r o j e c t s , TTI recommended t h a t ADOT adopt and implement optimization
techniques now a v a i l a b l e and used by other s t a t e s . Using computerized
a l g o r i t h m s , t h e s e techniques permit s e l e c t i n g those combinations of
p r o j e c t s t h a t produce the g r e a t e s t b e n e f i t s f o r each given budget l e v e l .
By considering d i f f e r e n t l e v e l s of improvements ( and defining the c o s t s
and b e n e f i t s ) f o r each highway l o c a t i o n under c o n s i d e r a t i o n , t h e s e
techniques can be used t o compare the many d i f f e r e n t p o s s i b l e combinations
of p r o j e c t s and then s e l e c t the combination which produces the g r e a t e s t
t o t a l b e n e f i t f o r a given expenditure. Experience shows the t o t a l
b e n e f i t s wtuch can be achieved using optimization techniques exceed the
b e n e f i t s which can be obtained through a simple cost- benefit ranking and
s e l e c t i o n of p r o j e c t s . TTI noted t h a t a few s t a t e s now use optimization
techniques and t h a t computer programs are already a v a i l a b l e .
Tort L i a b i l i t v
TTI found t h a t i n Arizona
" The l i a b i l i t y f o r t o r t s r e l a t e d t o highway d e f e c t s has
gradually been s h i f t e d from no l i a b i l i t y t o absolute
l i a b i l i t y over t h e p a s t twenty years."
This s h i f t i n l i a b i l i t y has a l s o been accompanied by increasing d o l l a r
l o s s e s and increasing numbers of claims. TTI addressed s e v e r a l concerns
r e l a t i n g t o l i a b i l i t y from an engineering p e r s p e c t i v e i n c l u d i n g :
a Keeping a l l highway hardware up t o the l a t e s t standards,
a Unknown highway d e f e c t s ,
a Control of access t o the highway, and
a Length of time t o f i l e a claim.
These concerns were addressed because the nature of TTI's review--
examining possible changes i n design and materials s p e c i f i c a t i o n s - -
n e c e s s i t a t e d a review of the p o t e n t i a l l i a b i l i t i e s t o the S t a t e t h a t might
r e s u l t from such changes. These i n t u r n lead t o a review of t h e c u r r e n t
t o r t l i a b i l i t y provisions i n Arizona as they relate t o highway d e f e c t s .
Their findings a r e discussed below.
Keeping Hardware t o Standards - From an engineering viewpoint, it is not
c o s t - e f f e c t i v e , nor generally necessary, t o keep a l l highway f e a t u r e s up
t o the l a t e s t accepted standards. Although many claims often involve
hardware not being up t o the l a t e s t accepted standards, TTI noted
". . . t h a t b i l l i o n s of d o l l a r s would be needed
annually t o keep the highway hardware c u r r e n t with a
constantly changing vehicle s i z e and constant upgrading
of standards. . . ."
TTI a l s o noted t h a t t h e v a s t majority of a l l hardware is reasonably s a f e
f o r a very high percentage of v e h i c l e s . Further, it is impossible t o make
hardware s a f e for every vehicle. For example, breakaway signs cannot be
made safe f o r motorcyclists.
TTI s t a t e d
'' It is not suggested t h a t t h e S t a t e should not be
responsible f o r unsafe f e a t u r e s . Rather, it is
suggested t h a t the S t a t e of Arizona should not be held
l i a b l e when roadside f e a t u r e s were designed t o the
accepted standard a t the time they were designed, f o r
which an e x t e n s i v e a c c i d e n t h i s t o r y has not been
observed, and which are reasonably safe f o r a
s u b s t a n t i a l majority of a l l expected impacts."
Unknown Highway Defects - TTI noted t h a t even on highways designed t o
standards, unsafe conditions can l a t e r ' d e v e l o p due t o a c c i d e n t s , weather
o r o t h e r f a c t o r s . To c o r r e c t such conditions requires t h a t ADOT be
n o t i f i e d and be given reasonable time t o e f f e c t r e p a i r s .
Control of Access - TTI found t h a t even though ADOT designs proper access
c o n t r o l s i n t o i t s highway system, c o u r t s have held ADOT responsible when
o t h e r p r o p e r t y owners have l e f t fence gates open t o allow c a t t l e t o graze
on the highway right- of- way.
Time t o F i l e Claims - According t o TTI
" The two year l i m i t a t i o n on the f i l i n g of claims f o r
highway d e f e c t s is a serious problem i n providing an
adequate defense f o r the S t a t e . Often, claims a r e
f i l e d eighteen t o twenty months a f t e r the incident
occurs which means accurate information about the s i t e
is v i r t u a l l y impossible t o o b t a i n . T h i s time gap
provides the p l a n t i f f with a s u b s t a n t i a l advantage over
the S t a t e . "
Suggested Guidelines - TTI suggests t h a t the S t a t e e s t a b l i s h guidelines
governing the S t a t e ' s l i a b i l i t y . TTI s t a t e d
" Providing the s t a t e a reasonable chance t o defend
i t s e l f through more s p e c i f i c l i m i t s on the conditions
f o r which the s t a t e w i l l be l i a b l e is a p r a c t i c a l way
t o l i m i t claims l o s s e s . The guidelines suggested i n
several s t a t e s involved t h r e e b a s i c t e s t s :
1. Was the purported highway defect the d i r e c t cause
of the incident?
2. Was the purported highway defect one t h a t had an
extended accident h i s t o r y o r one of which Arizona
Department of Transportation o f f i c i a l s had been
formally n o t i f i e d and had f a i l e d t o respond i n a
reasonable time?
3. Was the purported highway defect designed and
maintained i n accordance w i t h t h e s t a n d a r d s which
existed a t the time of its design?"
TTI believes t h e a r e a of t o r t l i a b i l i t y is s u f f i c i e n t l y s e r i o u s t o warrant
c o r r e c t i v e l e g i s l a t i o n . A model b i l l prepared by TTI t o address the
concerns l i s t e d above is included i n TTI's f u l l report.
a
ARIZONA DEPARTMENT OF TRANSPORTATION
206 South Seventeenth Avenue Phoen~ x, A r~ zona8 5007
BRUCE 6ABBITT
Governor
Mr. Douglas Norton
Auditor General
1 1 1 West Monroe
Suite 600
Phoenix, AZ 85003
March 31, 1983
Wl LLlAM A. ORDWAY
Dtrector
Dear Doug:
Thank you for the opportunity to review the
performance audit of ADOT Design and Materials
Specifications. This audit differed somewhat from
previous audits in that it was performed by an
out of state consultant. Our comments concerning
the Texas Transportation Institute recommendations
are attached.
As you point out, your audit report is a summary
of the major elements of the Texas Transportation
Institute final report. Our comments have been
summarized as well and we are retaining the vol. um-inous
backup data. If you, or members of your staff,
would like to review any of this data, please feel
free to call me.
Again, thanks for this opportunity to comment and
for the cooperation extended by you and your staff.
Cordially,
W. A. ORDWAY
Director
WA0: ejs
Attachment
HIGHWAYS AER0NAUT: CS ' hWTOR VEHICLE . PUBLIC TRANSIT ' ADMINISTRATIVE SERVICES ' TRANSPORTATION PLANNING
COMMENTS ON THE AUDITOR GENERAL'S PZRFORMRNCE AUDIT
After reviewing this complex and wide- ranging audit, ADOT
agrees with many of the recommendations, partially agrees with
others and, in one instance, strongly disagrees. ADOT also noted
a few recommendations that are currently provided for in existing
ADOT Standards. The chart following these comments provides a
breakdown of these four categories.
AGREE
The recommendations with which ADOT agrees cover a broad
range of topics. The page number shown provides an easy reference
to the Auditor General's report.
1. Redesign of inertia crash cushions for the smaller vehicle:
Page 6 & 7
ADOT's standards have been revised to accommodate this
recommendation.
Revision of Breakaway Cable Terminal Standards: Paye 6
ADOT1s standards have been revised to accommodate this
recomnendation.
3. Roadside mowinq, veqetation control and snow removal:
Page 6
The recommendations of TTI are currently being reviewed
and it is anticipated that standards will be revised in
accordance with these recommendations.
4. Uncrushed gravel: Page 6
TTI correctly points out that a substantial savings in
construction costs could be obtained by using uncrushed
river- run gravel. They also point out, however, that
I1 substantial savings in construction costs may be offset
by increased maintenance or rehabilitation costs in
excess of the initial savings." It is ADOT's feeling
that this is what would happen and the decision has been
made not to use uncrushed gravel and thus reduce overall
maintenance costs.
5. Compaction specifications: Page 9
ADOT agrees with TTI's comments that " under compaction"
is as important as " over compaction". ADOT has an on- going
program of compaction test analyses and if a problem is
indicated, the s2ecifications will be modified accordingly.
6. Tort Liability: Page 1 1
The TTI comments concerning tort liability are very timely
and point the way to substantial savings in state funds.
As TTI points out, however, additional legislation would
be required in order to relieve ADOT of near- absolute
liability that currently exists. ADOT is currently sup-porting
Senate Bill 1391 which, if passed, will provide
many of the features recommended by TTI.
PARTIALLY AGREE
ADOT partially agrees with the following recommendations made
by TTI.
1. Value Enqineering: Page 4
ADOT recognizes the importance of Value Engineering. Value
Engineering is not a new application but a formalization
of one segment of what has always been a part of good
engineering practice. In a broad sense, Value Engineering
has been practiced for many years by ADOT in the constant
review of new materials, methods and alternative design
features.
TTI stated that $ 10 to $ 13 million dollars could be saved
using Value Engineering techniques on a regular basis.
Analysis of the five- year construction program denonstrates
that approximately $ 162 million dollars of the total program
could be subject to a Value Engineering analysis. Therefore,
if the optimum conditions were present and Arizona could
realize the same percentage of savings as demonstrated by
the most successful state practicing Value Engineering, the
total savings would be $ 8.1 million over five years.
The actual savings would be much lower than this fiqure
since Value Engineering is practiced to some extent today.
The actual potential savings, considering the level of Value
Engineering practiced to date and the level of projects
on which it could be demonstrated may be $ 2 to $ 3 million
dollars over a 5- year period. To accomplish this level
of evaluation, resources in the form of space and added
personnel would be required at a cost of $ 200,000. per year.
Over a five- year period, the cost of conducting the recom-mended
study would be approximately $ 1,000,000., leaving a
net potential savings of approximately $ 2,000,000.
-
ADOT does, however, recognize the value of a program of this
type and will begin a inore formalized Value Enyinecring pro-gram.
2. Usinq High- performance sheeting in lieu of lightinq on over
head signs in rural areas: Page 6 •
ADOT agrees that the use of high- performance sheeting would
provide a savings over the use of lighting. In order to
realize this savings, however, sign installati- on must take
place. Since ADOT does not plan to replace any rural
illuminated signs during the next five years, or construct
any new signs, there will be no savings.
3. Elimination of the flared terminal W- beam end section:
Paae 6
ADOT agrees with TTI that a significant savings would be
accomplished by eliminating the flare terminal W- beam end
sections. The benefits in safety to the traveling public
exceed the benefits associated with the cost savings. A
continuing review of this item is part of ADOT's on- going
procedures.
Redesign of culvert and pipe headwalls: Page 6
Many attempts have been made to find an economical, traffic
safe headwall that does not reduce the capacity of the
culvert or increase maintenance costs. Any real improvement
in this difficult feature would be most welcome. Until
that design is accomplished, there can be no savings
associated with this recommendation.
5. Less restrictive temperature requirements: Page 7
TTI recommends a less restrictive requirement for stopping
pavement work due to ambient temperatures. ADOT will
examine compaction records to ascertain of the temperature
restriction should be amended.
6. Materials: Page 9
TTI recommends the use of the Lottman procedure for testing
asphaltic concrete aggregates and the use of the Texas
Gyratory Compactor for asphaltic concrete mix design
purposes. A30T will review each of these items to
determine if they have practical application in Arizona.
Chanqe to mechanistic design procedures: Page 9
Mechanistic design is a new concept which is to be the sub-ject
of a national study and possible inclusion in the
AASHTO Interim Guide. ADOT will await the results of this
study before making any decision on the applicability of
this procedure.
Project selection and prioritization: Page 10
The possible use of the optinurn transportation investment
analysis model may have some use in Arizona. ADOT will
continue to study this and other ways to improve our
project selection and prioritization procedure.
STRONGLY DI SAGREZS
1. Geometric Desiqn: Paqe 3
ADOT strongly disagrees with the TTI recommendations
concerning changes in geometric design standards.
Specifically, ADOT disagrees with the savings that TTI
associates with changes in ADOT standards on lane widths,
shoulder widths, sod shoulders and passing lanes.
TTI has recommended the use of minimum 6- foot shoulders
with 4- feet being sod. TTI has failed to recognize that
sod or earthen shoulders are not practical in desert
areas. It is only at considerable expense that any grass
areas are developed and in order to have sod shoulders,
irrigation would have to be provided. This type of
construction is totally impractical and would not be
considered since the cost would be in excess of $ 30 million
dollars over a five- year period.
TTI has also suggested side slopes of 3: 1 for fills over
five feet and 4: 1 for fills under five feet. This is an
ideal which ADOT has not yet reached. Current standard
sections for low volume roads include 14: 1 fill slopes
for higher fills and vary between 4: 1 and 1+: 1 for inter-mediate
fills. Considerable added cost would be exper-ienced
in construction and right of way if the flatter
slopes were adopted.
Beginning as early as 1955, ADOT has had a policy of
providing extra climbing lanes for trucks in lieu of
full widening. ADOT will continue to carry out this
policy.
TTI also recommended that ADOT adopt federal 3R standards
and that if we were to do so, a considerable savings could
be realized. To date, the 33 program has remained
undefined regarding minimum acceptable standards. FHWA
is currently working up standard guidelines which would
be the minimum for federal- aid projects. ADOT has maintained
the Arizona Highway System at the lowest possible cost
consistent with safety and service. To achieve those
standards suggested by TTI, the five- year program cost
would increase by as much as $ 300,000. per mile for the
3,750 miles projected for construction during the next
20 years. THE ADDITIONAL COST FOR TfIE NEXT FIVE YEARS,
WOULD BE BETWEEN $ 45 MILLION AND $ 260 MILLION DOLLARS.
EXISTING PHOCEDUi? ZS
There are two recommendations made by TTI that cover existing
ADOT procedures.
1. Use of span- wire mounted siqnal: Page 6
ADOT does use span- wire mounted signals when feasible in
accordance with our existing policies.
2. Increasing the lateral placement of certain siqns: Paye 6
It is ADOT'S policy to locate signs as far from the road
edge as is practical to enhance safety conditions.
3. Concrete median barrier: Paqe 6
This option is now made available to contractors in those
construction projects where a pre- cast concrete median barrier
is applicable.
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