Our study of the Tunnel-Lining Crack Index based on information about lining cracks obtained from a detailed inspection of a road tunnel which is managed by West Nippon Expressway Company Limited provides the crack configuration caused by shrinkage strain. We also inspected the actual environment inside the tunnel and measured the shrinkage strain of lining concrete that occurred in a short period of time. Through the analysis of shrinkage strain, the crack configuration of the lining concrete was analytically determined. Comparison of the crack configurations acquired by the inspection study and analysis reveals the correlation between the actual crack configuration due to shrinkage strain and the crack configuration based on the analysis. Regarding the cracks of the tunnel lining caused by internal factors, it is assumed that such factors, other than shrinkage strain, may be caused by uneven lining thickness, therefore, we studied effects of uneven lining thickness on cracks as well.