LA,eq,1h calculation:

- The calculation of the LA,eq,1h needs the knowledge of the number of passenger cars (PC) and the number of heavy trucks (HT) on a 1h-period.

LA,eq,24h (and Lden) calculation:

- The LA,eq,24h calculation needs the knowledge of the number of passenger cars (PC) and the number of heavy trucks (HT) for every hour of the day.
- In order to be as representative as possible of a yearly-averaged day, only working days are considered (from Monday till Friday).
- Within the DEUFRABASE, a mean behavior of the traffic flow of PC and HT can be considered, as well as, user-defined traffic data.

For both calculations, one need to consider the distribution of the PC and HT traffics on the road lanes:

- Two representative road situations are considered: (2 x 1) and (2 x 2) lanes. The width of each lane is 3.5m. In the (2 x 2) lanes case, a safety lane of 2m width is considered between the two directions.
- By default, the distribution of vehicles per lane (VPL) is obtained as a percentage of the number of vehicles per direction (VPD), following this rule:

Number of lanes | PC distribution/lane | HT distribution/lane |
---|---|---|

(2 x 1) | VPL = 100% * VPD | VPL = 100% * VPD |

(2 x 2) | Slow lane: VPL = 50% * VPD Fast lane: VPL = 50% * VPD | Slow lane: VPL = 90% * VPD Fast lane: VPL = 10% * VPD |