For the buckets of rain that drenches this city at this time of the year and the lack of proper drainage, and the sheer number of vehicles we drive, our roads are pretty decent. That's because some wise guy about 2 decades back set the concrete-isation of the roads rolling. I wish other cities in India would do the same too.
The rain, sea, humidity and the heat are not very kind to the roads, the city and the people who live here. If we humans were to abandon the city, it will take Mother Nature just a couple of monsoons to reclaim this city and return it to the original islands. However there's a good chance that the concrete roads will remain.