The relatively wide pavement, formed by the recommended five
lanes, and the flat character of the terrain, suggested to
you that specialized grading treatment may have to be applied
to the section to be reconstructed. Our comments in this re-
garca are as follows: ,

Current road-centre-line grade is about 0.16%. If, at Sta. -1+50
a pavement crossfall of 1% was applied from the ceritre line, the
gutter elevation would be (24' x 0.01) .24' below the road crown.
If at. Sta. 11450 a pavement crossfall of 3% was applied, the
gutter elevation would be (24' x 0.03) .72' below the road crown,
providing a relative difference of .48' between the two stations.
The combination of this difference with the existing road grade
would resuit in a gutter grade of 0.21%. This is a Marginal im-
provement. However, a 0.2% grade is considered by municipal eng-
ineers working in flood-plan areas, as a tolerable minimum if a
suitable increase in the number of catch~basins is provided. In
addition; north of the road, the swale can be designed for steeper
‘gradients and. larger capacity, and that is the side where the 36!
wide pavement will be draining to.

Another consideration is the hierarchy of Kingsway and Tyner Street.
In this regard it would be desirable to superelevate Kingsway along
the R. 150' curve; increase the gutter height at Sta. 1450, and
consequently steepen the gutter gxvade to about 043%. Such a solu-
tion would favour the major flow of traffic, while it would not
encumber the minor flow on Tyner Street. We would be pleased to
discuss with you the implications of such a grading.

It is to your discretion to consider either of these alternatives
or a combination of them for the most suitable solution to local
conditions.

We thank you for the Opportunity to be of service to you again.
Yours very truly,

| At (. uccy

ZOLTAN J.K. KUUN, P.ENG.

ZIKK/ jh

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