highly significantp < 0.001
In the “Out-of-sample validation” section, the text “we obtained digitised maps of AADT” has been amended to “we obtained digitised maps of AADT (work day averages)”; the text “27 and 87 empirical AADT values” has been amended to “28 and 87 empirical AADT values”; the text “highly significant ( p < 0.001) and positive (0.60 and 0.70, respectively)” has been amended to “highly significant ( p < 0.005) and positive (0.55 and 0.70, respectively)”; the text “The percentage of observations that fell within the 90% prediction interval was 85.2%” has been amended to “The percentage of observations that fell within the 90% prediction interval was 89.3%”; and the text “These percentage dropped to 63.3% and 77.4%” has been amended to “These percentage dropped to 63.6% and 77.4%”.