they were not slippery that I noticed in my town. not sure why. my town used dirt as the "mortar" between bricks, so there was no solid joint to degrade over

they were not slippery that I noticed in my town. not sure why. my town used dirt as the "mortar" between bricks, so there was no solid joint to degrade over time. I do remember crews going around and spreading small amounts of dirt on those roads, to refill what little rinsed away after spring thaw. they'd just have a guy following behind the truck with a push broom moving the dirt so it fell between bricks. dirt is dirt cheap.