International Journal of Academic Engineering Research (IJAER)   Year: 2020 | Volume: 4 | Issue: 9 | Page No.: 4-8 Investigating the Effect of Highway Geometric Design on Safety, Using a Safety Indicator within the Design Manual in Uganda. LION ENGR. ITAFE VICTOR ADACHA, HND (Civil), PGDPM, MNATE, MNSE, COREN Abstract: This paper investigates the effect of highway horizontal and vertical alignments design on safety within the context of design provisions in the Design Manual for Roads and Bridges (DMRB) using the Stopping Sight Distance (SSD) and Braking Distance (BD) as safety indicators. The curve radius/superelevations and gradient were investigated. The losses in SSDs and BDs were evaluated as provisions for curve radius/superelevations and gradients beyond the minimum desired values in the manual are adopted in a design. These losses were evaluated for several design speed bands using available geometric design formula and Microsoft Excel Software. At one step and two design speed steps below minimum desired radius, the SSDs lost on average across various design speed band was 25% and 44% respectively while the BDs lost was 35.8% and 63.6% respectively. The loss in SSDs and BDs across design speed bands increased at an average rate of 2.2% and 2.9% as the gradient increases by one percent. The BD which is a component of the SSD showed higher values meaning they are very sensitive. The relationship between the design of the considered parameters and the losses in SSDs and BDs may help give the highway design engineer a measure of how a design parameter that must exceed the minimum desired limit within a section of the entire design is impacting on the safety of the design. Keywords: Design Manual for Roads and Bridges, Geometric design, Highway, Horizontal alignment, Safety.