yes, they are residue from road repairs. called 'snakes' because they are a tar (or something) dribbled onto cracks which wind all over the road surface, this is usually done to asphalt road.
the snakes are most dangerous when newly poured or in very hot weather, which makes them very slippery. The random direction of the snakes allows your tires be thrown just about any direction that you do not want to go. hitting one at a high lean angle is especially exciting.

they do seem to be localized to the northern parts of the US and Canada. Or at least I haven't noticed them in the south or out west.

05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter