Table 2: Original statistics for the length and mileage.

Area Number Mean length Minimum Maximum Std. deviation Mileage Rural 374 0.968 0.063 5.998 0.989 362.100 Urban 2387 0.301 0.051 3.992 0.382 719.239 Network 2761 0.392 0.051 5.998 0.525 1081.339