There is still a street in Pittsburgh that is end-grain wood blocks. (In Shadyside, a short residential street.) They continue to treat it with tar. So I wonder if it was a similar idea.
Here's a street view link: https://goo.gl/maps/smQp7BpkgHF2
It's a bit of a random little stub street, so I'd never noticed it during my 4 years of undergrad, but it's a neat lil artifact.
https://www.ianvisits.co.uk/blog/2015/01/10/the-time-when-lo...
This seems to be a topic which animates a certain kind of urbanist nerd (of whom Ian Visits is the prince):
http://www.roadswerenotbuiltforcars.com/wood/
http://www.endgrain.org.uk/history/
That last page is from some Welsh applied research project on using more endgrain wood for surfaces; there's lots more interesting material on that site.
http://www.philly.com/philly/living/20151225_Changing_Skylin...