Annual average daily traffic

Annual average daily traffic (AADT) CONTOUR — 2,000-12,000 — 12,000-18,000... 

Figure 8.8 An overlaid map of the soil pollution index (Cu, Pb and Zn) and annual average daily traffic (AADT) data of the city of Hong Kong proposed by Lee et al. (2006).

T = annual average daily highway traffic, P = proportion of traffic required to slow down... 

The hazard assessment and bnffer/proximity analysis for the school identified both highway and indnstrial threats in the vicinity of Lufkin Middle School, as well as a CSX-owned railway located approximately one-half mile to the west of the school. The Clande M. Pope Memorial Freeway (US 1), lies only 75 meters from the school. This stretch of the freeway had an average annual daily traffic volume of eighteen to forty-one thousand vehicles. 

For the most performance requirement in the most common VRS application (roadside barriers), it is factors such as the presence of stractures and railway lines, the presence and proximity of bodies of water and non-deformable roadside obstacles, the average annual daily traffic and actual speeds and the presence of adverse road geometry which are most prominent. While factors such as aesthetics and cost are mentioned in some national guidelines and standards, their frequency is low. While the majority of the countries have guidelines and/or standards related to roadside and median barriers, there is generally limited guidance for other VRS systems such as crash cushions, transitions and MRS. 

To calculate the cumulative number of ESAL over a period of n years (design period), the daily number of ESAL and the average annual increase of commercial traffic must be known. 

Traffic analysis consists of estimating the axle load distribution spectrum (single, tandem, tridem and squad axle loadings) applied to the pavement structure. These data are obtained from WIM studies default values for axle load distribution are also available in case limited WIM data are available. The MEPDG does not use ESAL and hence does not require load equivalency factors. The MEPDG procedure, apart from average annual daily truck traffic, lane distribution, truck growth factor and axle load distribution, also utilises some new input data. These are the operational speed, the monthly and hourly distribution of traffic and the lateral wander of axle loads. 

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