HomeMy WebLinkAbout02/16/1988, 6 - CONSIDERATION OF PAVEMENT MANAGEMENT PLAN AND PASSAGE OF ORDINANCE AMENDING THE MUNICIPAL CODE REGARDING THE DESIGN OF STREET PAVEMENT. MEErIN
cityo San tins OBISPO Feb. 16, 1
REM NUMB
mmawn mW COUNCIL AGENDA REPORT
FROM: David F. Romero David P Pierce
Public Works Director 1255C Projects Manager
SUBJECT*Consideration of Pavement Management Plan and passage of
Ordinance amending the Municipal Code regarding the design of
street pavement.
CAO RECOMMENDATION:
Adopt Resolution Establishing a Pavement Management Plan and
pass-to-print Ordinance amending Traffic Indexes .
BACKGROUND:
For approximately 25 years prior to 1983 , City staff conducted annual
street surveys to determine which streets required maintenance. In
1983 the City decided to update its approach to Pavement Management
and accordingly hired CHEC Consultants Inc. to conduct a study.
Specific Objectives of the study are:
a. Evaluate pavement design and maintenance standards of the
City.
b. Develop a procedure to determine which maintenance actions
and priorities are most cost effective.
C. Develop a long term maintenance program which will prevent
deterioration of the City street pavements from the present
condition.
d. Protect the capital investment that has been made in
pavement systems.
The consultant has substantially completed his work which provided
the basis for the Pavement Management Plan prepared by staff . The
Plan discusses the City of San Luis Obispo street system, the
development and operation of the Pavement Management System, pavement
design and maintenance practices, and the backlog of pavement
maintenance and rehabilitation projects . The most important area of
the Plan is the recommendation of Policies.
POLICY DISCUSSION
A. Existing Policies
The City policies and standards are quite comprehensive for the
development of new streets . The City took the first step in
developing comprehensive policies pertaining to street maintenance by
adopting the following policies as a part of the FY 1987-89 Financial
Plan:
1 . The City will reconstruct, overlay or chip seal its streets at
standards and frequencies which will ensure the lowest street
life-cycle cost.
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COUNCIL AGENDA REPORT
Council Agenda Report
Pavement Management Plan
Page 2
2 . The City will not reconstruct or overlay its streets unless
proposed locations have been recommended and scheduled through an
approved Pavement Management Plan. Projects in the Pavement
Management Plan ,will be developed consistent with the policies
for capital improvement management.
3 . When outside parties necessarily make utility cuts in the street
pavement or run overweight vehicles over streets , the City will
recover from these parties the full costs of repairing damage or
deterioration caused by their actions .
B. Proposed Policies
The Council should consider the following policies which are proposed
in Chapter II of the Pavement Management Plan:
1 . Design
POLICY:
The Desicrn of Street Pavements should provide for the most
economical life-cycle costs to the City.
ACTIONS:
Modify City Engineering Standards to provide:
a) A Design Period of 20 years, unless a shorter period is
approved for a specific reason.
The design period is the length of time a street should last
if no rehabilitation work is performed. A 20 year design is
the accepted standard recommended by Caltrans . A shorter
design period may be appropriate if the configuration of the
street will be changed within 20 years.
b) The Traffic Index (TI) is a measure of traffic that will use
the pavement during the design period. A 10 percent
increase in Traffic Index represents doubling of traffic.
The TI used for pavement design should be based on a 20 year
projection of traffic. The minimum values in the current
development standards are based on 10 year traffic volumes.
These values should be increased to the 20 year values shown
in the table below. This change will increase construction
costs about 15 percent and will double the pavement life.
Thoroughfare 10.0 - presently specified as 9 .0
Arterials 8.0 - presently specified as 7 . 0
Collector 7 .0 - presently specified as 5 . 5
Local 5.5 - presently specified as 5 . 5
Commercial 8 .0 - presently specified as 7 .0
/Industrial
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Council Agenda Report
Pavement Management Plan
Page 3
C) An R-value of 5 should be used for all designs, unless the
value is determined by testing. The R-value is a measure of
resistance or strength of the soil on a scale of 0 to 100 .
Strength increases with increasing numbers.
I
The expansive clay soils within the city provide very little
strength for a pavement structure. Tests of native soils
typically give R-values between 5 and 10. Conservative
designs provide adequate streets at a low life-cycle cost .
d) Street Profiles should be designed to allow a minimum of
three inches of overlay to be added without causing problems
with driveway approaches or drain inlets .
When pavements are overlayed there are frequently problems
with automobiles striking the -pavement due to the change in
the angle between the driveway and the street . The
solutions are to reconstruct the pavement without the
increased crown, to replace the sidewalk and driveway
approach, or to thin the overlay which creates a weak area
in the pavement . The latter is often chosen as it is the
only economical solution; however, it creates a dip for
through-traffic and will require spot repairs of the
pavement at a later date.
e) Design Procedures and Engineering Standards should generally
follow CalTrans practices.
These are accepted practices that have been followed in the
past.
2 . Maintenance Seal Coats
POLICY:
Chip Seal Coat should continue to be the primary seal used on all
Local , Collector, Arterial , and Thoroughfares throughout the city
except in the downtown core.
DISCUSSION:
Seal coats are required to separate the asphalt pavement from
sun, oxygen and water in order to prevent premature breakdown of
the asphalt cement. The Chip Seal is the most economical seal
coat . A chip seal lasts 8 to 10 years on local streets and costs
half of a one inch overlay which would last 10 to 15 years. Most
significantly, the chip seal adds only 3( on an inch to the
thickness of the pavement. The build up of the crown of the
street determines when reconstruction is required. The chip sea
has not been used in the downtown because of the disruption, and&V5
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Council Agenda Report
Pavement Management Plan
Page 4
dust caused during the construction and because the volume of
traffic would require the seal to be replaced every four to six
years.
3 . Maintenance in the Downtown
POLICY:
Maintenance in the downtown business area should be designed to
avoid frequent disruptions.
ACTION:
The primary maintenance in the downtown should be joint sealing
and asphalt overlays that will require less frequent disruption
than seal coats and will provide a more aesthetically pleasing
appearance.
DISCUSSION:
This reflects past practice that the streets in the downtown area
between Palm and Pacific from Santa Rosa to Nipomo have not been
chip sealed. These streets were overlayed in the early 1970 's to
improve appearance.
4 . Level of Maintenance
POLICY:
The City should maintain the higher volume streets to a higher
level of repair.
ACTION:
Maintenance or rehabilitation of a street should be scheduled
when the defect rating scores computed by the CHEC Inc Pavement
Management System exceeds:
Class of Street Defect Score*
Thoroughfares 100
Arterials 100
Collectors 150
Locals 200
s
The Defect Score is the sum of • the values assigned to each of
the defects identified during the visual inspection. A higher
number indicates that the street is in worse condition.
DISCUSSION:
User costs increase as the condition of the pavement
deteriorates. Maintenance of high volume streets will give the
best returns in reduction of vehicle operating costs . Also the
high volume streets have the most rapid rate of deterioration
when maintenance is delayed.
����!lti►ivillllll�ll° ��llll city of san Lina osispo
COUNCIL AGENDA REPORT
Council Agenda Report
Pavement Management Plan
Page 5
5 . Damage to Streets
POLICY:
Development and construction projects should pay for the cost of
deterioration of the existing streets .
ACTIONS:
The City should implement a fee for construction and development j
to compensate for the damage caused to Local and Collector.
The methods of assessing and collecting the fee would be
developed while the City Financial Study is being completed.
DISCUSSION:
Local and Collector streets are designed for automobile traffic
and truck traffic associated with home deliveries , trash pickup,
street sweeping and other occasional use by trucks. However, the
loadings associated with construction of houses and with the
development of property at the end of existing streets is not
normally accounted for in the original design. The cost of
constructing a standard residential street and adding a two inch
overlay at a later date is $525 ,000 per mile. Over the life of
the pavement, the cost to the public for each truck that travels
on the street is :
Type of vehicle Cost per mile
Large Two Axle Truck $8 . 20
3 Axle Truck $9.85
3 Axle Dump Truck 20. 50
3 Axle Dump with Trailer 27 . 90
Standard Tractor Trailer 18 . 85
6 . Bus Routes
POLICY:
Bus routes should be restricted to streets which have been
designed specifically for the additional loads.
ACTION:
When bus routes are changed to travel over Local or Collector
streets an evaluation of the increased cost in street maintenance
should be part of the decision process.
DISCUSSION:
The bus traffic is a very substantial part of the loading on any
street because of the weight and the frequency. Buses account
• for over 30% of the loading on Arterials and for between 60% an
90% of the loading on collector streets that have bus traffic . •
����►�hildlllllh��hl���l City Of Say i LUIS OBISPO
_ COUNCIL AGENDA REPORT
Council Agenda Report
Pavement Management Plan
Page 6
The cost of the additional wear on the street should be
considered along with factors such as service to customers and
route timing when a route change is being evaluated.
Trucks over 10,000 are already restricted to designated routes
except for making pickups and deliveries to buildings that are
not on a truck route. (MC 10. 48 . 040)
C . INCREASED FUNDING FOR FY 1988-89
Staff is recommending that an additional $140, 000 be identified
from unappropriated General Fund revenues for the Streets/-
Pavement Program of the Capital Reinvestment Plan in FY 1988-89
to prevent an increase in the backlog of overlay and
reconstruction projects during the current two year Financial
Plan.
The Pavement Management Plan identifies a $2 , 430, 000 Backlog of
Overlay and Reconstruction Projects. In addition to the backlog
the Plan identifies an annual need of $370, 000 for contract
overlay and reconstruction projects in order to prevent further
deterioration of the street pavement system. A total of $740 , 000
is required during the two year period of the current financial
plan to keep the backlog from increasing. The Financial Plan
already identifies a total of $585 , 000 for projects on the
overlay and reconstruction list . ($540 ,000 on page E-7 and $45 , 000
within the Higuera Widening on page E-12) The additional
$140, 000 will raise the two year total to $725 ,000 which will
prevent a net deterioration of the streets system during these
two years.
Funding of any backlog reduction would be deferred until the next
Financial Plan
D. DEFERRED POLICY AREAS
Policies are needed regarding the acceptable level of backlog and
the additional finances that are needed to reduce or prevent the
increase of the backlog. Specific policies in these areas are
deferred until the completion of a scheduled Financial Study that
will look at all City revenues and expenses .
ACTIONS:
City staff will prepare recommended policies regarding acceptable
levels of backlog and on methods of financing street
rehabilitation work while the Financial Study is being completed.
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COUNCIL AGENDA REPORT
Council Agenda Report
Pavement Management Plan
Page 7
DISCUSSION: I
This plan addresses only the maintenance and rehabilitation of
street pavements. Finances have to be considered along with
other street requirements and other demands on City resources .
The County in conjunction with the Cities is considering an
increase in sales tax for transportation needs and the City is
reviewing all other sources of revenue. Upon the completion of
these two timely actions, a more comprehensive and accurate
picture of the financing available for street work will be
available.
The present operating budget provides $460,000 per year for
pavement maintenance which is sufficient to Chip Seal ten percent
of the streets, repair potholes and isolated failures , repair
trenches, and paveout to new curbs and gutters. This funding is
adequate for these tasks provided the funding for the overlay and
reconstruction program is increased.
Several options will be evaluated in the formulation. of a policy
on the level of the backlog. These include accepting some level
of backlog as being tolerable, and reducing the backlog to that
level over a period of years or even through a bond issue . No
alternative has been selected as being preferred. Options that
have been talked about include:
a") . Accepting the $2 ,430 ,000 backlog as the best we can afford
and not allowing it to increase. The Pavement Management Plan
indicates that $370 ,000 per year is required for overlay and
reconstruction projects to keep the street system in its present
overall condition.
b) . Eliminating the $2 ,430 ,000 overlay and reconstruction
backlog during a given time period which would cost the $370, 000
per year plus a portion of the backlog reduction. The annual
cost would be:
Years to eliminate backlog Annual cost
5 $870,000
10 $620 ,000
15 $540 ,000
20 $500,000
c) . Reducing the backlog to $1 , 000,000 during a given period of
time which would cost the $370 ,000 per year plus a portion of the
backlog reduction. The annual cost would be:
Years to eliminate backlog Annual cost
5 $670 ,000
10 $520,000
15 $470,000
20 $450,000 /_
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COUNCIL AGENDA REPORT
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Pavement Management Plan i
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d) . Sale of $2 ,430,000 worth of 20 year bonds to eliminate the
backlog at this time would require the expenditure of
approximately $545 ,000 ( 1987 $) per year for the next 20 years.
The repayment of 8 . 5% bonds would be cost $255 ,000 per year for
20 years. When adjusted for an inflation rate of 4 percent, the
$255 ,000 becomes $175,000 in 1987 dollars. Adding the $370,000
annual cost of future deterioration gives a cost of $545 ,000
( 1987 $) per year .
D. PAVEMENT MANAGEMENT SYSTEM PRIORITY
The project priority assigned by the Pavement Management System is
based on the visual defect score, the truck traffic, and the total
traffic on the street. A heavily traveled street will deteriorate
more rapidly and will cause greater cost to the motorist than the
short local street that has few cars, essentially no trucks and low
speeds . Therefore the program will recommend maintenance on a fairly
good arterial ahead of reconstruction of a minor local street that
has a high defect score.
E. ENVIRONMENTAL DETERMINATION
The Pavement Management Plan received a negative declaration during
environmental review on October 21 , 1987 .
F. FISCAL IMPACT
The identification of $140,000 from unappropriated General Fund
Revenues to the Streets/Pavements Capital Reinvestment Program will
prevent an increase in the backlog during the current two year
Financial Plan. Policies pertaining to the reduction of the backlog
and sources of revenue are deferred until the completion of a
scheduled Financial Study.
STAFF RECOMMENDATION
Staff recommends that the council rebiew, modify and adopt a
resolution establishing a Pavement Management Plan with the policies
contained therein and pass-to-print Ordinance amending Traffic
Indexes.
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RESOLUTION NO. (1988 SERIES)
A RESOLUTION OF THE COUNCIL OF THE
CITY OF SAN LUIS OBISPO APPROVING A
PAVEMENT MANAGEMENT PLAN
WHEREAS, The City retained the services of CHEC Consultants Inc. to
evaluate the pavement design and maintenance practices of the City and to
prepare and install a pavement management system; and
WHEREAS, said evaluation of design and maintenance practices has been
campleted; and
WHEREAS, Said Pavement Management System is installed and operational;
and
WHEREAS, The Pavement Management System has identified a backlog of
overlay and reconstruction projects costing $2,430,000
NOW THEREFORE BE IT RESOLVED by the Council of the City of San Luis
Obispo as follows:
SECTION 1. The Pavement Management Plan hereto marked Exhibit "A" and
incorporated herein by reference is hereby approved. This plan includes
policies, goals, and actions for implementation and will guide management
of pavement design, maintenance, rehabilitation and reconstruction.
SECTION 2. The policies will be incorporated into Engineering
Standards as the Standards are revised.
SECTION 3. An additional $140,000 is identified from unappropriated
General Fund revenues for the Streets/Pavement Program of the Capital
Reinvestment Plan in FY 1988-89.
SECTION 4. The City Clerk shall furnish a copy of this resolution and
a copy of the approved Pavement Managenent Plan to the Directors of the
Public Works, Community Development, and Finance Departments
On motion of secozded by
and of the following roll call vote:
AYES:
NOES:
ABSENT:
the foregoing Resolution was passed and adopted this day of
198 .
MAYOR RON D'JNIN
ATTEST
CITY CLERK PAM VOLES
s : s s s +� •
APPROVED:
City ninistrative Officer City Atttey
Fi irector Public Works Director
----------
Car
�Car nity Development Director .-City
ORDINANCE NO. (1988 SERIES)
AN ORDINANCE OF THE COUNCIL OF THE CITY OF SAN LUIS OBISPO
AMENDING SECTION 16.36.140 (STREET TYPE AND REQUIREMENTS)
OF CHAPTER 16.36 (SUBDIVISION DESIGN AND IMPROVEMENTS)
OF THE SAN LUIS OBISPO MUNICIPAL CODE
WHEREAS, The Traffic Indexes established in Section 16.36.140 are based
on a 10 year design life; and
WHEREAS, the Traffic Index is a measure of the number of vehicles that
will drive over a pavement during the design life; and
MM AS, California Department of Transportation and most other design
agencies recommend a 20 year design life; and
WHEREAS, The City of San Luis Obispo has adopted a Pavement Management
Policy that the design of street pavements should provide for the most
economical life-cycle costs to the City; and
VAERFAS, the increase in Traffic Index will double the design life of
pavements and increase the time until reconstruction is needed by at least
10 years at an estimated increase in construction cost of fifteen percent;
NOW, TFER]M'ORE, BE IT ORDAINED by the Council of the City of San Luis
Obispo as follows:
SECTION 1. Section 16.36.140 is hereby amended to updated the Traffic
Indexes for the following Street types in the "Chart of street types and
requirements"
STREET TYPE TRAFFIC INDEX
CUL-DE-SAC (access court) 5.5
HILLSIDE CUL-DE-SAC 5.5
RESIDENTIAL COLLECTOR 7.0
OOMHKCIAL/INDUSTRIAL MINOR 8.01
ARTERIAL 8.0
THOROUGHFARE (highway) 10.0
(I
Ordinance No. (1988 Series)
Page 2
SECTION 2. This Ordinance, together with the ayes and noes, shall be
published once in full, at least three (3) days prior to its final pawn
in the Telegram-Tribule, a newspaper published and circulated in said City,
and the same shall go into effect at the exparation of thirty (30) days
after said final passage.
INTRODUCED AMID PASSED-TO-PRINT by the Council of the City of San Luis
Obispo at a meeting held on the day of 198 , an
motion of seconded by
and on the following roll call vote:
AYES:
NOES:
ABSENT:
MAYOR RON DUNIN
ATTEST
CITY CLERK PAM VOGES
APPROVED:
City strative Officer City At V
Vrney
Cc mmmity Development Director Public Works Director
ty Engineer <Q I
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