October's Surface - Reading the Post-Monsoon Road
The monsoon season is over. The afternoon thunderstorm window that ran from late June through September 30 is closed for the year, but what monsoon left behind stays on the road for weeks. October's surface is post-storm debris layered over four months of sediment transport, and it reads differently than the surface you were riding in June. What Changes During monsoon, afternoon storms drop water faster than the roadway drains it. Water moves across pavement, carrying sand, gravel, and organic material from the shoulders and the surrounding terrain. When it drains or evaporates, that material stays where the water deposited it - typically at pavement edges, in low spots, and at the inside radius of curves. Four months of that accumulation is now baked onto the road. Without the daily flushing action of afternoon rain, it compounds. Dust settles on top of it. Morning dew or an overnight sprinkle puts a moisture layer underneath without washing anything away. A surface that looked cl...