HomeMy WebLinkAbout- - Measure M Eligibility Attachment 3 - 6/15/2010The condition of each street segment is rated on a scale of "0" to "100" with 100 being
the best rating. The result of surface distresses called the Pavement Condition Index
(PCI) provides a basis for comparing the relative condition of each street segment. By
comparing the calculated PCI for each segment against an established PCI for a
roadway segment deemed acceptable (PCI= 89), staff is able to determine future
rehabilitation needs based on cost effectiveness, and determine present status of the
arterial streets in the system. In addition, projections are made to determine the effect
a variety of funding scenarios have on the condition of the overall street system.
uallty
Index
Proposed Treatment
Ve Good
90-100
None proposed
Good
84-89
Slurry Seal
Fair
73-83
Thin Overlay
Poor
60-72
Thick Overlay
Very Poor
0-59
Reconstruction
The City's pavement management software evaluates each deficient street segment
by using a list of possible rehabilitation strategies with a unit cost assigned to each
strategy. These strategies are used in the outcome branches at the bottom of decision
trees. The decision trees utilized to select cost effective repair strategies are
illustrated in the Parametric Data Report in Appendix G. Each street analyzed will fall
into one of these branches based on the conditions tested in the decision tree. The
rehabilitation strategies identified in each branch will repair, the condition that caused
the street segment to fall into that branch. If more than one strategy occurs in a
branch, the most cost effective strategy will be selected.
The cost effectiveness of each rehabilitation project is calculated based on the benefit
of implementing the improvement strategy divided by its cost.
The benefit of implementing the strategy is the "area" under the projected performance
curve as shown on the figure below. This accounts for both the initial increase in PQI
or service level and the extended life. Total benefit is derived by multiplying the "area"
by the user miles on the street section (street length X AADT).
F4,70170,10"',
final analysis involves applying the available budget to the needs and determining
what project should proceed if sufficient funding is available to meet all the needs.
The projects are selected on the basis of highest cost effectiveness ranking to ensure
that greatest benefit will be derived for the funding available in each year.
The analysis of the collected data indicates that the majority of the City's arterial
pavements are in a serviceable condition. A "needs driven" report (Appendix D)
shows those streets with a PCI equal or lower than PCI of 89, which are currently in
need of rehabilitation or reconstruction. It is estimated the City would have to spend a
total of $82,517,322 in 2010 to address the arterial street rehabilitation requirements.
Included with this report are updated Geometric, Traffic and Structural data on the
City's arterial streets. Appendices A, B, and C present these data.
Surface Distress Data is illustrated in Appendix E for each arterial street. The Surface
Distress Data provides a useful reference, which shows what surface defects are
present on each street segment. The rating includes both the severity (how wide are
the cracks) and the extent (how much of the street is affected) for each distress. The
individual ratings for each distress on a street segment are combined into an overall
Surface Distress Index (SDI) for each section.
Using Performance Prediction models, the deterioration of each street segment is
projected over the life of the street, starting from its present condition.
The point in time each street segment will need some form of rehabilitation can be
determined by applying a minimum acceptable PGI or service level of 89. The year
each street will reach this point can then be determined. The resulting Need Driven
Rehabilitation Report for the next ten years is contained in Appendix D.
84-89
11.8%
The City of Costa Mesa
2010 Pavement Condition Index (PCI)
First Year of Analysis: 2010
90-100
9 a.y°r° 60-72 0-59
8.7% 5.9%
Pavement Information Table
PCI Range
0-59
60-72
73-83
84-89
90-100 Total
No. of Sections
19
28
35
38
202 322.0
% of Sections
5.9%
8.7%
10.9%
11.8%
62.7%
Lane Miles 1
15.1
19.4
27.0
38.9
172.6 273.0
of Lane Miles
5.5%
7.1%
9.9%
14.2%
L 63.29