Structural road design aims to ensure the road is strong enough for the expected number of vehicles in a certain number of years. The input of a calculation is the number expected of vehicles (e.g 10,000,000) divided in groups (f.e. lorries, vans, cars) and the number of years that the road has to function before the road structure has to be fully renewed (e.g 20 years).
In the given example of 20 years, it doesn't mean that there is no maintenance during this period. There is a certain amount of maintenance, but it can be scheduled and is low.
Engineered roads in the age of horse-drawn transport aimed for a maximum gradient of 1 in 30 on a macadamized surface, since this was the steepest a horse could exert to pull a load up hill, which it could manage easily on the flat.
Roads (except those on private property not accessible to the general public) are typically paid for by taxes (often raised through levies on fuel), though some public roads, especially highways are funded by tolls.
On the side of the road there may be retroreflectors on pegs, rocks or crash barriers, white toward the direction of the traffic on that side of the road, and red toward the other direction.
Feeds |
Contact