Rumble Strips On Slow Narrow Curving Indian City Lanes

The U.S. Department of Transportation states that:

"A rumble strip is applied along the direction of travel following an edge line or centerline, to alert drivers when they drift from their lane."

Now consider the brilliance of adding Rumble Strips to slow narrow curving city lanes, that are barely 5 feet across.

Possibly second only to traffic signals on top of flyovers.