The bearing capacity of subgrade soils is necessary for the design and construction of transportation
infrastructure, such as roads, and airfields. The determination of bearing strength of soil could be
tedious, expensive and time-consuming. There is need to establish models that would predict the
bearing strength parameters such as California bearing ratio (CBR) using simple and less time-
consuming laboratory tests. This study examines the relationship between CBR and index properties of
Makurdi shale. Forty-five samples of the shale were collected; index properties and CBR were
determined and correlated. Using multiple linear regression analysis, it was established that the soaked
CBR could be predicted from the shale index properties such as moisture content, specific gravity,
liquid limit, shrinkage limit, optimum moisture content and maximum dry density with adjusted 𝑹𝟐 of
0.838. Also, soaked CBR may be predicted from the soil properties like moisture content, liquid limit,
plastic limit, shrinkage limit, optimum moisture content and maximum dry density with adjusted R2 of
0.838. Based on the results of this study, it is recommended that models 1 and 2 could be used for
prediction of soaked CBR of Makurdi shale using corresponding soil index properties such as moisture
content, specific gravity, liquid limit, plastic limit, shrinkage limit, optimum moisture content and
maximum dry density.