Accounting the dynamic effect of vehicles using the dynamic load allowance factor has beenrnwidely accepted in bridge engineering. However, consensus on the evaluation of the dynamic loadrnallowance factor is yet to be reached and this is because large number of parameters affects therndynamic load allowance factor. Bridge span length, fundamental frequency of the bridge andrnvehicle, bridge type, bridge material, damping, vehicle speed, vehicle weight, number of axles,rnnumber of vehicles and vehicle loading position are the parameters used to study the dynamic loadrnallowance factor by different researchers and national bridge codes. rnMany national bridge codes have stated different provisions for the dynamic load allowance (DLA)rnfactor. The different codes have specified the DLA factor in terms of bridge span length, as arnfunction of road surface condition, based on different limit states, bridge fundamental frequencyrnand design loading configurations. This indicates significant variation in bridge code provisionsrnfor dynamic load allowance factor exists and this thesis paper tries to asses and determine newrnappropriate dynamic load allowance formula for reinforced concrete Slab and Girder highwayrnbridges. rnIn this study, a complex finite element software called CSI Bridge 20 is used. In modelling;rnstandard bridge lane width, different span length for both Slab and Girder bridges, design loadingrnconfigurations and vehicle speeds used to determine the appropriate dynamic load allowancernfactor. rnMoving load analysis is done to get the static response and time history analysis is done to get therndynamic response. The static analysis using the finite element software is validated using influencernline method and the dynamic analysis is validated using analytical solution and field investigationrnconducted on KOKA bridge. rnFinally, new dynamic load allowance formula is set as a function of bridge span length and vehiclernspeed using regression analysis. Conclusions and recommendations drawn based on the researchrnfindings.