Roads: An estimated 6% of Kolkata's area is under roads, whereas a standard modern city demands 25–30% of the area be under roads. "Pucca" (surfaced) road construction started in Kolkata only after 1839, and pavements were provided along the main roads only to facilitate erection of gas lights. In 2010–11 KMC maintained 1,909 km of roads (1,670 km surfaced and 239 km unsurfaced). In 2011, the number of registered motor vehicles (including two and three wheelers) on the roads of Kolkata was 687,918.