Research Article
Development of a Relationship between Pavement Condition Index and International Roughness Index in Rural Road Network
Table 4
T-test results for predicted and observed pavement condition index.
| | 
 |  | IRI range |  | Paired differences | t | df | Sig. (2-tailed) |  | Mean | Std. deviation | Std. error mean | 95% confidence interval of the difference |  | Lower | Upper |  | 
 |  | 2.5–3.5 | PCIO–PCIP | −0.244 | 1.15 | 0.081 | −0.40 | −0.08 | −2.98 | 779 | 0.483 |  | 3.5–5 | PCIO–PCIP | 0.070 | 1.37 | 0.10 | −0.13 | 0.27 | 0.67 | 163 | 0.499 |  | 5–7 | PCIO–PCIP | −0.085 | 1.41 | 0.09 | −0.26 | 0.09 | −0.92 | 144 | 0.357 |  | 
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| PCIO,  observed pavement condition index; PCIP,  predicted pavement condition index. |