The article says "safest roads," but the statistic used to demonstrate that is deaths per 100K people rather than deaths per kilometer driven.

Seems to me the latter would be a much better metric for the safety of the physical roads.

Yes, and the footnote also says that "this metric is age-standardized". I did not easily find an explanation of what that means, which made me distrustful of the data.

Fortunately, good old Wikipedia has what we are both looking for:

https://en.wikipedia.org/wiki/List_of_countries_by_traffic-r...

For me the upshot is that UK still comes out quite good amongst its European peers, but the difference appears to be smaller.

Not sure I completely agree (if the definition of vehicles is cars). That disregards miles travelled by cyclists and pedestrians etc. If 10% of the population switched from driving to cycling to work but the death numbers stayed the same, that metric would go up but really nothing would have changed, either mortality wise or in terms of number of people using the roads.

This would introduce a bias towards countries that are large and have extensive motorway networks. They would appear safer than countries that have a smaller portion of motorway miles.

> If we look at the number of deaths per billion miles driven, we see that motorways are roughly four times safer than urban roads, and more than five times safer than rural roads. This is not specific to the UK: among 24 OECD countries, approximately 5% of road deaths occurred on motorways.5 In almost all countries, it was less than 10%.

I prefer the death per people metric as I am more interested in how likely I am to receive some bad news than some metric based on distance.

Both measures have bias, the "per people" metric doesn't take into account when people are actually driving while the "per kilometer" metric puts too much emphasis on long distance driving, which is usually done on motorways where it is the safest. Maybe the best metric would be "per time spent on the road, including as a pedestrian on the sidewalk", but I guess it is harder to estimate.

Anyways the UK is doing well on both metrics.

Possibly even per trip? I'm confident my bicycle trips to the supermarket in the Netherlands is safer than a trip to Walmart in the US by car, but I spend way fewer kilometres doing the same job. That only makes it even safer, but I think is discounted in per-KM statistics?

Montana would be amazingly safe based on your metric.