321 
PARK AND CEMETERY . 
1 
CONSTRUCTION and MAINTENANCE of PARK DRIVES 
' Paper read befo''e American Association of Park Superintendents 
bv H. S. Richards, Asst. Superintendent South Parks, Chicago 
One of the most serious problems 
the Park Superintendent has to deal 
with is the maintenance of driveway 
surfaces, and it becomes specially 
serious if his jurisdiction extends over 
a system of city boulevards which 
are used for more than merely pleas- 
ure driving. It is a problem shared 
in common with other city o.fficials 
who have charge of streets, but the 
case of the park man is often the 
worst. With him there is no regu- 
larly organized street department 
with its recognized needs for a defi- 
nite appropriation, and the money 
used for driveway maintenance most 
generally is taken from what would 
otherwise be available for landscape 
work, buildings, plantations, floral dis- 
play and others of the more obvi- 
ous functions of the park. After all, 
drives and boulevards are only means 
to other ends. They provide access 
to the park and are in themselves or- 
namental only when properly set off 
by trees, lawns or flowers and thus 
become part of the picture. They 
are permissible only w'hen they lead 
to buildings, to desirable points of 
view, or provide necessary routes of 
travel. 
Being then so essentially utilitarian 
in their nature, their construction 
should be from the standpoint of 
utility. Build as few as we need and 
as w^ell as we can afford. A well 
built driveway should be free from 
dust or mud, reasonably permanent, 
and agreeable to the eye under a 
bright sun. If it is free from dust and 
mud it will be reasonably permanent, 
for dust and mud are caused by 
grinding away the surface. Macadam 
or crushed stone in some form is 
the most universally used material on 
road surfaces. It provides a con- 
siderable degree of permanence, but 
is by no means, even wdien made of 
the best material, free from dust and 
mud. Travel is increasing every- 
where, both in quantity and speed, 
and the standard of street and road 
maintenance demanded by the public 
is growing higher and higher, espec- 
ially since the automobile has come 
into such extensive use. For these 
reasons the park superintendent, in 
common with the superintendent of 
streets and country roads, is hard 
pressed to find some means of per- 
manently improving his macadam sur- 
faces, or some substitute therefor. 
Macadam' i-s 'comparatively cheap, 
while any form of street asphalt, 
stone or wood block or brick pave- 
ment heretofore available for city 
streets is comparatively expensive be- 
sides objectionable for other reasons. 
Something between the two in cost 
is demanded ; something that will 
utilize the existing macadam, and 
which can be supplied without an ex- 
pensive plant or a highly trained 
force. An application of oil or tar to 
the surface which in either case might 
be crude or refined, was first sug- 
gested as an improvement in this 
direction, and the use of these ma- 
terials, either neat or in the form 
of emulsions has been quite extensive 
throughout this and other countries, 
as various published reports show. 
]\Iuch benefit has been derived from 
the use of oil and tar in suppressing 
dust and holding the surface particles 
together, but where the traffic attains 
a considerable volume they have been 
found only temporary in their effects 
— palliatives rather than cures for an 
existing evil. To have any value as 
a binder the tar or oil must penetrate 
beneath the surface, and this it can- 
not do in a well filled and compressed 
macadam, if heavy enough to have the 
desired binding qualit}n The neces- 
sarily small quantity and thin layer 
used deteriorates rapidly, is much af- 
fected by moisture and freezing, and 
especially in the case of tar, becomes 
brittle in cold weather and rapidly 
w-ears away. Dust and moisture on 
the road surface at the time of appli- 
cation prevents penetration and 
proper adherence and when once the 
thin protecting surface is broken 
through the macadam below crumbles 
easily for lack of needed moisture. 
The use of these materials has been 
quite extensive in Chicago on the 
boulevards and park drives, and, as 
much of the work there was done 
under the writer’s supervision, these 
statements are made as the results of 
ab.'olute experience. 
The failure to obtain the desired 
permanent result or economy of 
maintenance by surface applications on 
ordinary macadam suggests the ad- 
visability of specially preparing the 
surface for the reception of the tar 
or oil by cleaning off dust, spiking up 
and bringing the coarse stone to the 
surface, or by the application of a 
layer of new stone, all for the purpose 
of securing greater penetration and 
better binding effect. This, too, has 
been tried on our Chicago boulevards 
with variable results. In some cases 
the result seemed to justify the in- 
creased expenditure, while in others 
the results were not good on account 
of the use of too much tar or oil, 
moisture in the road surface, or the 
unequal distribution of the coarse and 
fine stone. 
The cost of one surface application 
of refined tar, applied hot without 
dilution, is from six to seven cents 
per square yard without anything al- 
lowed for redressing or new stone. 
A heavy California or Texas oil may 
be applied in the same way for ten 
cents, while if the surface is specially 
prepared or new stone used, the cost 
of a macadam surface treated with tar 
or oil preparations may vary from 15 
to 40 cents, per square yard. "Very 
few macadam surfaces that have been 
used for any length of time are in a 
condition to receive this sort of sur- 
face treatment without some redress- 
ing or new stone, so the minimum 
figure given above will nearly always 
be exceeded, and often very greatly. 
The method of treatment I refer 
to above is what may most properly 
be called the Penetration Method, 
which generally implies that the 
bitumen used is heavy enough to act 
as a binder between, the particles of 
stone, that it must be heated when 
applied, and to be effective it must 
penetrate a certain depth. The 
method of application is briefly as 
follows: 
The bitumen, either heavy oil or 
tar, is heated in portable wagon tanks 
to approximately 200 degrees Fahren- 
heit and then spread upon the road 
surface from pouring cans or hose 
attached to the outlet pipe of the 
tank. If cans are used they may have 
spouts with a very broad thin outlet 
so as to spread the bitumen in a thin 
sheet. The same sort of nozzle may 
be used on the hose, but perforated 
spouts or nozzles are too easily 
choked up for this sort of material. 
As the bitumen is distributed it is 
brushed evenly over the surface with 
brooms and allowed to stand until 
cold so as to secure as much penetra- 
tion as possible. An average of from 
two-thirds to three-quarters of a gal- 
lon per square yard is generally used. 
'When cold the surface is covered with 
