【正文】 ffer economic alternatives for shortspan bridges in the United States and particularly in developing countries where castinplace concrete is mon practice. The main advantage of castinplace concrete slab bridges is the ability to field adjustment of the roadway profile during construction. Typically, the design of highway bridges in the United States must conform to the 3 American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Highway Bridges (2021) or AASHTO Load and Resistance Factor Design (LRFD) Bridge Design Specifications (2021). The analysis and design of any highway bridge must consider truck and lane loading. However, truck loading provisions govern for shortspan structures when considering AASHTO Standard Specifications. AASHTO specifies a distribution width for highway loading to reduce the twoway bending problem into a beam or oneway bending problem. Alternately, an empirical expression for liveload bending moment is provided. Therefore, reinforced concrete slab bridges are designed as a series of beam strips. AASHTO Standard Specifications design procedures were originally developed in the early to mid 1900s based on research work by Westergaard (1926, 1930), Jensen (1938, 1939), and Newmark (1948). The goals of AASHTO LRFD Bridge Design Specifications were to develop prehensive specification and achieve more uniform margin of safety for all bridge structures. AASHTO LRFD procedures specify HL93 live load which is a bination of HS20 trucks or design tandem with lane loading. AASHTO permits a reduction in liveload intensity on a bridge deck due to the improbability of having all lanes of bridge superstructure loaded simultaneously. These liveload reduction factors are used to account for the probability of having all lanes loaded at the same time and at locations along the bridge deck producing the maximum bending moment in an element of a bridge superstructure. AASHTO Standard Bridge Specifications and LRFD procedures specify that results obtained from analyses of three and fourlane bridge decks where all lanes are loaded simultaneously are to be multiplied by reduction factors. Sanders (1984) summarized and dated the various changes in the AASHTO Standard Specifications over the years and noted that these reduction factors were originally introduced in 1941 in the third edition. However, Sanders (1984) also reported that the greatest confusion appears to be in the appropriateness of using the provisions of reduction in load intensity for determining the design bending moments in a girder. Some engineers permit the reduction of live load, while others do not. Taly (1996) reported that bridge designers 4 disagree on the correct interpretation of AASHTO regarding the reduction of live load in longitudinal beams for bridges carrying more than two traffic lanes. The load reduction on steel girder bridges was investigated by Mabsout et al. (2021). In this study, a parametric study was conducted to assess the effect of multiplepresence design trucks on wheelload distribution for bending moments and deflections in three and fourlane bridges. The results of bridge cases with reduced truck loading were pared to fullyloaded bridges and assessed with AASTHO procedures. Mabsout et al. (2021) reported the results of a parametric investigation using the 3D finite element analysis (FEA) of straight, singlespan, simply supported reinforced concrete slab bridges. The study considered various span lengths and slab widths, varied number of lanes, and varied live loading conditions for bridges with and without shoulders. Longitudinal bending moments and deflections in the concrete slab