Info

6 m < w

—(f)

3 m

w- 3 X /7|

Note : For example, for a carriageway width of 11m, n\ = Intjj-jJ = 3, and the width of the remaining area is 11 - 3x3 = 2m.

Note : For example, for a carriageway width of 11m, n\ = Intjj-jJ = 3, and the width of the remaining area is 11 - 3x3 = 2m.

(2) For variable carriageway widths, the number of notional lanes is defined in accordance with the principles used for Table 4.1. The number of notional lanes will be :

-1 where w < 5,4 m -2 where 5,4<w<9m -3where 9m<w<12m

(3) Where the carriageway on a bridge deck is physically divided into two parts separated by a central reservation, then, unless otherwise specified :

(a) each part, including all hard shoulders or strips, is separately divided into notional lanes if the parts are separated by a fixed safety barrier;

(b) the whole carriageway, central reservation included, is divided into notional lanes if the parts are separated by demountable safety barriers or another road restraint system.

NOTE : A departure from these rules may be justified depending on envisaged future modifications of the traffic lanes on the deck.

4.2.4 Location and numbering of the lanes for design

The location and numbering of the lanes should be determined in accordance with the following rules :

(1) The locations of notional lanes are not necessarily related to their numbering.

(2) For each individual verification (e.g. for a verification of the ultimate limit states of resistance of a cross-section to bending), the number of lanes to be taken into account as loaded, their location on the carriageway and their numbering should be so chosen that the effects from the load models are the most adverse ; see however clause 4.3.4(3a).

(3) However, for infrequent, frequent and fatigue representative values and models, the location and the numbering of the lanes may be specified for particular projects to correspond to the traffic conditions normally expected. For characteristic values, departures of location and numbering from (2) above may only be specified for particular projects where it can be shown that they result in effects approximating to the most adverse, or by the client.

(4) The lane giving the most unfavourable effect is numbered Lane Number 1, the lane giving the second most unfavourable effect is numbered Lane Number 2, et cetera (see Figure 4.1).

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