Whilst true this is also misleading in that road wear is not completely from trafficking, and so the 1400x just looks at the marginal difference. The proportion

Whilst true this is also misleading in that road wear is not completely from trafficking, and so the 1400x just looks at the marginal difference. The proportion of wear accountable to your relatively fixed externalities (weather, water, utilities) depends on the type of road and the location. But say if 60% of the wear is due to weather and water, the 1400x factor comes across very misleading. To put more simply - if you banned semis roads would not last 1400x longer, nowhere near in fact.