Truth behind Mumbai’s potholes: There’s no method, only madness
Why do potholes resurface? Because BMC and PWD don’t follow the prescribed method of cutting out the area around a crater and letting it dry fully.Updated: Jul 25, 2018 16:20 IST
For Mumbaiites, the monsoon is synonymous with potholes. Every year, the first few heavy showers convert the city’s roads into adventure sport tracks, putting motorists’ driving skills, health and patience to ultimate test. But according to experts, this can easily be prevented. How? By following the scientific procedure to repair the existing potholes.
Experts claim both the Brihanmumbai Municipal Corporation (BMC) as well as public works department (PWD) don’t follow the prescribed steps while fixing potholes. The result is for all to see – BMC has recorded more than 1,400 complaints of potholes in June and July, with some on roads that were repaired recently.
CLAIM AND THE COUNTER
Civic officials blame potholes on waterlogging, and a bad drainage system. “Immediate action is taken against contractors found guilty of shoddy work. The city’s drainage system is old and seepage is common. This weakens the roads. Wherever there is waterlogging, there are potholes,” said a BMC official.
This may not be entirely true. Sanjay Singh Gaharwal, from the research wing of Central Road Research Institute (CRRI), said, “Potholes are mainly a result of poor quality road construction and unscientific method of repairing them. This, combined with waterlogging, causes roads to lose their durability.”
According to Gaharwal, the standard operating procedure to fix a pothole involves cutting out the area around the pothole in a rectangle, removing loose gravel and cleaning it. The portion has to be dried and then refilled with the mix.
“Potholes can’t be wet during repairs. Even a small quantity of water is enough to unsettle the mix,” Gaharwal said. “Also, cutting out the area is important to fix that part of the road.”
Under pressure with heavy vehicular traffic, BMC officials hardly follow the entire procedure. “Some potholes are repaired as they are, without cutting out the edges, as the method is quicker. As potholes surface during the monsoon, there is hardly a long spell of no rain to let the crater dry.”
EXPLANATION AND EXPERT SPEAK
While your ride remains bumpy, BMC believes the cold mix is working well. Municipal commissioner Ajoy Mehta said, “BMC has recorded fewer potholes this year in comparison to the previous years. Our response time is shorter. The new cold mix is showing good results. We have seen it work on wet patches too.”
Explaining why they can’t wait for a pothole to dry, CP Joshi, secretary (roads), PWD, said, “The prescribed scientific method for filling potholes is essentially for work after the monsoon. During the rains, we can’t use anything other than the cold mix. That too is mostly a temporary measure for three-four months. While repairing potholes during the monsoon, we sometimes adopt a quick method to fill the pothole for convenience of motorists.”
Proper categorisation and study of potholes could help. Ashok Datar, a transport expert, said, “Mumbai is more vulnerable to potholes because of intensive rainfall and heavy traffic. The civic body needs to have a measurement mechanism to map, compare, analyse and measure potholes. This is presently not done. For instance, a 500m stretch having eight-nine potholes is a serious concern. It should be studied and such potholes should be categorised, similar to the study of waterlogging spots in the city.”
DRYING POTHOLE: According to experts, irrespective of the type of mix being used, the area around the pothole can’t be wet. Water prevents the repair mix from drying, ensuring potholes resurface
SHAPE: It is important to create a rectangular cavity around a pothole, clean it and fill it with the repair mix. In some cases, BMC does not do this and fills the pothole directly to save time. This causes potholes to reappear
HURRY: Ideally, the repaired area should be opened for traffic only after one hour, but this is not followed strictlyHOT MIX VERSUS COLD MIX
2010-11: The civic body starts to use hot mix – hot asphalt and hot-sprayed bitumen with stone chips –to fill potholes. It faces criticism as potholes continued to appear
2012: BMC decides to try cold mix – a bitumen-based formula – as it can be used even when it rains, if the pothole is wet, and dries faster. BMC allots Rs50 crore for the project
2014-2018: BMC uses hot mix, which needs dry spell
2018: BMC reintroduces cold mix technology, which is procured at a cheaper rate, claiming the mix imported from Austria and Israel gave good results in June 2017. To bring down the cost further, BMC decides to buy the ingredients from a German firm, and uses its own raw material to manufacture the mix at its Worli plant. The patented mix is said to have strong chemicals to prevent it from disintegrating.