Referring to those loads placed on the superstructure after the deck has cured and begun to work with primary members in resisting loads: sidewalks, railings, parapets, signing, utilities and the wearing surface.   

It is specified by 3 components:

• a uniform surface load to be applied over the roadway width (sdl) – referred to in AASHTO as load type DW (i.e. dead load of wearing surfaces and utilities). For this load both Roadway width (rww) and Roadway eccentricity (rwe) can be defined.
• 2 line loads acting on the left (lll) and right (llr) side of the superstructure cross-section – referred to in AASHTO as load type DC (namely DC2 in literature, i.e. dead load of nonstructural attachments like barriers, railings, sidewalks). The eccentricity of both line loads (ell and elr) can be specified with respect to the CG of the superstructure.

A proper distinction between DW and DC2 loads is required for considering the respective load factors for the particular load types stored in the summation load cases of self-weight and SDL loads which are used in the combination table. I.e.:

SUM-SW = DC (DC1 + DC2) loads

where DC1 are the loads as defined in the window for Self-Weight

and DC2 the line loads (lll + llr) as defined in the window of SDL

SUM-SDL = DW loads as defined in the window of SDL for the uniform surface load (sdl)

Informatively both summation load cases will be summed up in one load case for the total dead load, i.e.:

SUM-DW = SUM-SW + SUM-SDL