I recall seeing something a year or two ago where a consultancy came in to examine the problem of flooded roundabouts. They concluded that it was cheaper and easier to pump water out of flooded gutters on the few rainy days a year than it was to dig them all up and install drains.

The problem to me isn't really the lack of drains to take water away from the side of the road, it's the poorly built and maintained roads where potholes and uneven surfaces pool with water in the middle of the road. Personally I don't think drains are that necessary, but resurfacing and leveling the roads might not be a bad idea.