If the road is continually flooded with clean water or clean water is running, bubbling or trickling down the road even if it appears to be draining away (especially if there has been recent excavation work in the vicinity) then this is likely to be a water leak.
If the road is flooded with dirty, smellywater or it is running, bubbling or trickling down the road (especially if there has been recent excavation work in the vicinity) then this is likely to be a foul sewer problem.
In both cases you should contact your local Water Authority particularly if the water is causing a hazard or is threatening property.