Abstract: An 11 km long section of the Kazancı-Gümiişova Motorway is located on a soft alluvial soil. It is considered that determinationof consolidation characteristics of the alluvium soil, forming the basal soil along the studied motorway route and having low bearing capacity, is essential for the selection and design of art structures and for the in-profile optimization of the motorway embankment.In this study, data obtained from detailed in-situ and laboratory tests carried out on the basal soil at preliminary design andconstruction stages were evaluated. Based on the evaluated data, studied section of the motorway was divided in