Imperial Valley press., 1920-04-12
COM MISSION !:
RECON- MMENDS
) inch BASE
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apparent to all who take the troubl
10 investigate, have forced us to loo
Tor the pavement having the longes
IKE. 1t is our earnest desire t
ADOPT for San Diego county a pave
ment which we can assure the tax
payers will continue to give goo
service at low maintenance cos
fo< more than the average life O
the bonds
SADDLED WITH DEBT
'We believe the people of thi
county and of the state are educated
beyond the point of approving tn,
construction of cheap, makeshift O,
substitute pavements in order t,
stretch a certain appropriation over
a certain distance. The experienc,
OF some of the California countie:
which have already bonded them
selves to the limit for highway paving
added to the experience of the Cal
ltornia highway commission itself
! shows that such construction cannot
be justified financially, not from the
standpoint of satisfaction to the
travelling public. Some of the wealthy
eastern states which have been con-
structing highways on the basis of
cheap cost for 20 years, are now
awakening to the fact that they are
saddled with debt, and have little in
the way of permanent construction
to show it. 1t is our ambition that
San Diego county will not find herself
SJn1Ilar fay,
hence. Low first cost should not be
too seriously considered.
Our personal investigation, and
the digest of the expert opinions of
paving authorities in this, as we'll as
other states, force us to the convic-
ton that the safest type of pavement
to build for county highway use,
consists of hydraulic Portland cement
concrete base, covered with a bitum-
inous surface ofe one and one-half to
two inches of Warrenite, Topeka
asphalt, sheet asphalt or other SIM
liar surfacing. The structure of
such pavement satisfies all practi-
cal as well as theoretical require
ments. Its adoption is sound from
any angle. The resistent qualities
of the earth sub-grade, often unreli-
able, are reinforced and aided by the
foundation of concrete, which in trun,
supports and is protected by the re-
silent covering of a more or less
elastic material. The base should
outwear more than one surfacing coat.
The two prime factors in a success
full pavement are thus present, the
foundation and the wearing surface.
This type of pavement, with a cement
concrete base not less than five inches
in thickness which should be made
heavier and reinforced where the
sub-grade is treacherous, will be the
most economical pavement for San
Diego county, and will give longest
life, with least repairs.
I'VE have no quarrel with any
other type of pavement now being ad-
vocated for use on the county highway
sistem. There is, undoubtedly, merit
in all of the other types, but we can
not reconcile their general adoption
and use to the long term of our
bonds. The minimum thickness of
six and one-half or seven inches of
pavement, which we favor, composed
of course designed for foundation,
and a separate course designed for a
wearing surface is unquestionably
superior to lessor thickness of all
elastic and yielding materials. There
should be no disagreement on this
point.
CONCRETE CONSTRUCTION
"Under date of September 26, 1919,
we filed with your honorable board
our report, which described the main
highways to be improved, and rec
commended the type of construction in
the following words:
we recommend that said roads
be improved by permanent concpete
construction
GAS this report, was adopted by
your honorable board, and referred to
in your call for the election as a
description of the plan of procedure
to be followed if the bonds carried
the voters of San Diego county have
adopted the report and it's terms
and it is now beyond our jurisdic,
ton to change to any other type OF
pavement than the type mentioned
in the report. At another place II
the same report we referred to data
secured regarding the average cos'
of concrete roads, which data wa!
used in compiling our estimate. Thi!
plainly indicated that the type o.
road upon which the report wa
based was to be of concrete construc
ton. We do not believe we can g
back of the report as made to you
honorable board and approved by tn
people.
"Further analysis of the type o
pavement which we believe shoul
be adopted shows that it has bee
the experience in the state of Cali
fornia, and eastern states, that, elm
mating urban traffic conditions, tn
placing of an asphaltic wearin
surface upon a hydraulic concret
foundation may safely be delayed TO
a period which will vary in accord
ance with the traffic, and with tn
quality of workmanship and mater
ial used in the concrete base.
| ONLY SAFE CONCESSION
| "This fact indicates to us the onl
safe concession to be made to firs
cost. An asphaltic wearing surface
as described above, which should u
timately be constructed, would, on tn
L I L fxt,~is