Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-12-08
Takes Issue With Engineers
Recommendations to Change
Present System:
DIRECTOR ASKS SURVEY
OF TRAVEL ON AVENUE
Would Learn Needs to Put Flexible
Progressive Signals
in Use.

q
visibility of placing WaShingtons traf-
f1c light system on a central control
basis, Traffic Director william H. Har-
land has filed a report with the Dis
trict Traffic Council answering recon-
mendations by j. Rowland Bibbins,
consulting engineer, that such a Sys-
tenn be installed here.
Mr. Harland, however, recommended
that a survey be made of the traffic
conditions on Rhode Island avenue
northwest from Twelfth to First street.,
where traffic light signals are now in
operation, to determine what will be
required to change the present Tim
tied progressive system" to the "flex-
ibie progressive system" advocated by
Mr.. Bibbins.
There is considerable difference of
opinion between the traffic director
and Mr.. Bibbins as to the system of
traffic light operation best adapted to
the needs of Washington. Mr.. Har-
lands report was in effect a reply to
statement by Bibbins to the council
several weeks ago advocating certain
substantial changes.
Speed Reported Lower.
"In the first place." Mr.. Harland
said, 1.-The average rate of speed re-
ported by Mr.. BibbinS for some of our
the average rate of speed made on
these streets"
Mr.. Bibbins has told the council that
with master or central cycle speeds
may be raised or lowered at any time
to accommodate both non-rush and
rush hour conditions"
To this Mr.. Harland replied: eff 1t is
to be understood from this statement
that the entire signal system of the
~ fNy DC 10 ha
timer there is, In my opinion, grave queS-
ton as to whether Mr.. Bibbins' plan
will be satisfactory. For example, the
total cycle of the downtown business
area will be different from the cycle
which would be advisable on certain
outlying streets and the outlying streets
in one part Of the city may operate
on different cycle from the outlying
streets in another part"
Mr.. Harland pointed out that in
Pittsburgh, where the latest and most
modern installation in the country is
in operation, there are 10 different mas
ter timers in different parts Of the city
and 81 isolated intersections controlled
by signal lights. Although these sig
mails are not centrally controlled. Mr..
Harland declared, it is true that in
the downtown section Of that city the
signals are controlled by one master
timer.
Still an Experiment.
"This plan in Pittsburgh and in some
other cities is still in the experimental
stage" he said, "but it Is very doubtful
whether it could be considered good
practice to connect all timing signals
and equipment to one master timer"
Mr. Harland also devoted some time
to a discussion of Mr.. BibbinS' conten-
ton that the average traffic speed In
Washington can and should be raised.
Attention is called to the fact" he
declared, that no traffic control should
raise the speed beyond the known safe
capacity of the street. for to do so
would segregate the vehicles into two
Such a segregation would result in such
traffic confusion as to diSarrange the
flexible progressive system"
After expressing his conviction that
traflc speed in Washington compares
very favorably with other cities, Mr..
Harland stated:
However, while I am not fully In
accord with Mr.. Bibbins' plan to refine,
as understand. our entire signal system,
do agree that it may be possible by
such refinement to increase the speed
and capacity of some of our main
arteries, but that no steps should be
taken in this direction without a
thorough study OF traffic conditions.
Recommends Survey.
with this in view I recommend, sub
ject to the approval Of the Board of
Commissioners, that a survey be made
Of traffic conditions on Rhode Island
avenue northwest from First to Twelfth
streets, where traffic-light signals are
now in operation, to determine Just
what will be required to change the
present limited progressive system to
the flexible progressive system in order
that we may determine under actual
operating conditions just what can be
expected of a system of this kind and
how far it would be advisable to extend
it to other signaled streets in the
District.
ut is believed the selection of Rhode
Island avenue for this experiment Is an
ideal one, as the traffic there is of con-
siderable volume.
IF such recommendations are to be
carried out the necessary funds will
have to be provided for the survey. 1
quite agree with Mr.. BibbinS that we
need some funds in the District with
which to carry on trafdc survey work,
to make traffic counts and to analyze
such studies SO that we can make our
installations on basis Of fact"
The traffic council has voted to ask
Congress to appropriate $11 200 for this
survey, and to provide the mechanical
means Of putting into effect the change
on Rhode Island avenue.
According to Mr.. Bibbins, this change
will permit traffic to move from First
to Twelfth streets at speedy and even
rate without encountering any red
lights.