--------------------+----------+-------+-----+-----+-------+---------- | |Granite|Wood | | Sheet | Pavement Qualities |Percentage| Block |Block|Brick|Asphalt|Bitulithic --------------------+----------+-------+-----+-----+-------+---------- Cheapness | 14 | 8 | 8 | 13 | 14 | 12 Durability | 21 | 21 | 16 | 12 | 15 | 15 Easiness of cleaning| 15 | 10 | 14 | 15 | 14 | 14 Light resistance to | | | | | | traffic | 15 | 13 | 14 | 15 | 11 | 12 Non-slipperiness | 7 | 7 | 4 | 6 | 5 | 6 Ease of maintenance | 10 | 10 | 8 | 6 | 6 | 6 Favorableness to | | | | | | travel | 5 | 2 | 5 | 3 | 4 | 4 Sanitariness | 13 | 9 | 13 | 10 | 12 | 12 +----------+-------+-----+-----+-------+---------- Total | 100 | 80 | 82 | 80 | 81 | 81 Less cheapness | | 72 | 74 | 67 | 67 | 69 --------------------+----------+-------+-----+-----+-------+---------- The Forest Service of the U. S. Department of Agriculture presents the following table: --------------------+----------+-------+-------+------+-------+----- | |Granite| Sheet | | | Wood Pavement Qualities |Percentage| Block |Asphalt|Brick |Macadam|Block --------------------+----------+-------+-------+------+-------+----- Cheapness | 14 | 4 | 6¹⁄₂ | 7 | 14 | 4¹⁄₂ Durability | 20 | 20 | 10 | 12¹⁄₂| 6 |14 Ease of maintenance | 10 | 9¹⁄₂ | 7¹⁄₂ | 8¹⁄₂| 4¹⁄₂ | 9¹⁄₂ Ease of cleaning | 14 | 10 | 14 | 12¹⁄₂| 6 |14 Low resistance to | | | | | | traffic | 14 | 8¹⁄₂ | 14 | 12¹⁄₂| 8 |14 Non-slipperiness | 7 | 5¹⁄₂ | 3¹⁄₂ | 5¹⁄₂| 6¹⁄₂ | 4 Favorableness to | | | | | | travel | 4 | 2¹⁄₂ | 4 | 3 | 3 | 3¹⁄₂ Acceptability | 4 | 2 | 3¹⁄₂ | 2¹⁄₂| 2¹⁄₂ | 4 Sanitary qualities | 13 | 9 | 13 | 10¹⁄₂| 4¹⁄₂ |12¹⁄₂ +----------+-------+-------+------+-------+----- | 100 | 71 | 76 | 74¹⁄₂| 55 |80 --------------------+----------+-------+-------+------+-------+----- Crosby gives three sets of ideal crusts for country roads: _V_ for main roads, carrying a fairly heavy mixed traffic, _W_, secondary roads carrying moderate traffic, and _X_ on minor roads with light farm travel almost wholly.[186]