Pavement Roughness Modeling Using Regression And Ann Methods For Ltpp Western Region
Table 1: SPSS: Correlation between variables considered in the analysis
| CN = Construction Number | Combined CN1 to CN4 | |||||
| Yearly IRI (m/km) | Initial IRI, IRI0 (m/km) | Pavement Age (Year) | Structural number (SN) | Cumulative ESALs | ||
| Pearson’s R | Yearly IRI (m/km) | 1.000 | 0.464 | 0.197 | -0.145 | -0.128 |
| Initial IRI, IRI0 (m/km) | 0.464 | 1.000 | 0.225 | -0.009 | -0.149 | |
| Pavement age (Year) | 0.197 | 0.225 | 1.000 | -0.132 | 0.458 | |
| Structural number (SN) | -0.145 | -0.009 | -0.132 | 1.000 | -0.077 | |
| Cumulative ESALs | -0.128 | -0.149 | 0.458 | -0.077 | 1.000 | |
| Sig. (2-tailed), ɑ = 0.05 | Yearly IRI (m/km) | 0.000 | 0.000 | 0.001 | 0.003 | |
| Initial IRI, IRI0 (m/km) | 0.000 | 0.000 | 0.840 | 0.000 | ||
| Pavement age (Year) | 0.000 | 0.000 | 0.002 | 0.000 | ||
| Structural number (SN) | 0.001 | 0.840 | 0.002 | 0.072 | ||
| Cumulative ESALs | 0.003 | 0.000 | 0.000 | 0.072 | ||
| Number of Sample, N | 544 | 544 | 544 | 544 | 544 | |
| Sample Mean, x̅ | 1.401 | 1.274 | 20.8 | 5.4 | 3,511,167 | |
| Standard Deviation, SD | 0.561 | 0.374 | 7.5 | 1.4 | 5,001,990 | |
| Coefficient of Variation, COV (%) | 40.0% | 29.4% | 35.8% | 25.9% | 142.5% | |