Another objection to asphaltic roadways is that they cannot with safety be constructed of greater gradient than 1 in 60, and it must also be borne in mind that fine weather is necessary both for the construction and repairs of a roadway of this description.
Very little smell, and that not of an unpleasant character, arises from the work when compressed asphalte is being used, the mastic is however temporarily unpleasant to those who dislike the odour.
With reference to the question of the cost of compressed asphalte for roadways: it is of course a matter depending upon local circumstances as to the first cost, but it must be remembered that the compressed asphalte hitherto laid has been nearly all that of the Val de Travers Company, who charge a fixed price per square yard for laying according to thickness required, the distance of the locality from London, and other local circumstances. With reference to maintenance, this is a question dependent mainly upon traffic, but here again the company will undertake to keep in repair at so much per square yard per annum for a certain number of years.
It would, however, perhaps be a better plan not to enter into such an agreement, but to arrange for repairs under a schedule of prices, but this must greatly depend upon the character of the work in the first place, and other local considerations.
Mr. Ellice Clarke gives the following as the cost of Val de Travers compressed asphalte.[95]
The cost is reduced to 100,000 tons per annum per yard of width.
| Original Cost per Square Yard. | Interest on original Cost. | Maintenance per Square Yard. | Scavenging per Square Yard. | Total. | ||||
|---|---|---|---|---|---|---|---|---|
| s. | d. | d. | d. | d. | s. | d. | ||
| 18 | 0 | 9·7 | 3·6 | 0·4 | 1 | 1·7 | ||
Nothing is charged for renewal, as the annual sum for maintenance provides the asphalte in perpetuity.[96]
The following table[97] may here be of use:
Table showing the agreed Cost per Annum of certain
Asphalte Carriageway Pavements in the City of London.