Evening star., 1935-11-03
Highway System Development
Problem for american Cities
Reouiirements of Modern Traffic and
Pedestrian Safety Must Be Met
in improvements.
in improvements.

rect tramc lnCo Inc QeSlred ana Te.
quired channel Of flow. In effect, Ian.
ing is to free-wheeled vehicles what
the rails are to the street cars and
trains.
Results Of Laning.
The results to, be expected from
laning are: ~ The lessening Of con.
fusion. (2) reduction Of accidents.
90 classification between slow mov-
ing and heavy-duty vehicles and the
lighter, faster-moving passenger cars,
90 orderly arrangement Of vehicles
at the approach to intersecting streets,
90 more expeditions movement Of
trafic and 60 increased street ca
pacity.
Lanes, arrows and sometimes q
word or two marked on the pavei
ment to direct trafic into proper
position to make q left or right turn
or to rotate around the circle lessons
confusion. Such markings In q short
time become familiar to regular drivers
and are in the best possible place
to give information to strangers.
When lines are marked there is a
degree Of assurance to each driver
who keeps within his own proper
lane that he may proceed with rea-
sonable security and not expect his
right Of way to be taken by some
other driver. Both Of these reasons
have q tendency to reduce accidents.
With proper laning and proper width
4f ~f~ AZ infArxarfiNnS three
more vehicles abreast can get away
as one when the signal changes, but
three in line require much more time
to get into motion. one after the
other. In the case Of segregating
trafic, lane marking permits the
fastest vehicle lane to proceed unin-
terrupted. II slow-moving vehicles
are all over the street, the entire
tratic movement is reduced to the
speed Of the slowest.
I think that those Of you who have
driven cars in Washington before the
director of vehicles and traflc started
to lane our streets will agree with me
that we have been able by laning
the principal intersections on our
main streets to greatly increase the
capacity of those streets. The de-
partment of highways has adopted as
standard in asphalt pavements the
construction of permanent center line
marking in all roadways Of 40 feet
and over in width. With proper
laning and proper use Of those lanes
I am satisfied that any street system
will carry from IS to so per cent more
traffic than II the streets were not
laned.
New Problems In Auto.
Most Of our streets were designed
and laid out in the days Of the horse
drawn traf1ic. Since those days con-
ditions have changed and the auto
mobile has brought new problems to
be solved by the highway and trafic
engineer. One Of these involves the
curb radius at street intersections.
Traffic and street improvements have
now progressed to the point. In most
cities. where 1t Is obvious that wide
curb returns are not only advantageous
but necessary for the smooth fiow Of
trafflc. It Is equally obvious that as
the radius of curhs Is increased the
speed of vehicles making turns In
cfeases with resultant rise in hazard
and Inconvenience to the pedestrian.
These facts, therefore, have to be
taken into account in increasing the
radit Of curbs. =
In general, 1t may be stated that
the proper curb radius Is one that will
at least allow the turning vehicle to
proceed in its new direction without
interrupting more than one moving
lane of trafic, provided. however. that
the crosswalk distance is not increased
to such an extent as to cause addi-
tional hazard to the pedestrian.
Washington has another problem
that is even more complex than that
If trafic lanes. curb radii or street
width, and that Is the handling OF
traffic at our multiple intersections
and circles.
The City Of Washington has more
circles than any other city in the
world, and, for this reason. 1t is in
teresting to know something about
their development.
Salient Features in Plan.
The original city plan Of Washing
ton. as designed by Maj. L'Enfant, the
French engineer and city planner, had
for its salient features the Capitol
and the Washington Monument, which
determined the axis for the Mall, and
the Executive Mansion. which, with
the Capitol and the Monument, formed
a right-angled triangle.
The street system was laid out with
the Capitol as q center, the lettered