 Keeping West Sussex moving is a top priority for the County Council, and tackling these things is a key part of that. Officially, they're highways defects, otherwise known as potholes. After record levels of rain and freezing temperatures, even more have been appearing all over the UK, and they can be anything from an irritation to a downright danger. The number of potholes in West Sussex can triple after heavy rain or snow. We've been watching the gangs at work to find out how they mend them and to take a look at some of the reasons that they can suddenly appear. A big problem is water seeping in between the layers of the road surface. It could be from something like this blocked stream, and even an earlier repair can then break up. If the water freezes, the expanded ice makes things even worse. Operation Watershed is a County Council initiative focused on flooding, but it also means the number of pothole patrols has been tripled to keep up with the faster rate at which they're appearing. It's a two-man gang that will go out to those areas where we're getting a significant number of potholes on a particular road, and they'll work their way along that road and repair all the potholes along it in one hit. The gangs start by cutting a rectangle around the uneven patch and preparing it for filling. There are different ways to fill potholes using hot and cold fillers depending on the size and type of pothole and what sort of road it's on. The process begins by sealing the edges of the rectangle with a spray bitumen. Then the hot tarmac is tipped in and smoothed out. The gangs, by the way, are pretty good at doing a straight line by eye. And this is the machine that hammers it all into place. It's a vibrating plate known as a wacker because, well, it delivers a whacking movement and this is the tamper which ensures the corners are properly tamped down. In emergencies, this glue can be poured in to help the tarmac stick and then there's this remarkable bag of tarmac which is actually laid cold and, unfortunately, you can't buy it in the shops. When it's finally been whacked and tamped, the repair cools very quickly. Then it's safe to walk on or even to drive a vehicle over. How long will the pothole repair last? A temporary job is done if the road is due to be resurfaced otherwise it'll be a more lasting one. What can you do to help? In an emergency, you can report a pothole by calling 01243 642 105. You can also use the Love West Sussex website or smartphone app and don't worry that someone may have reported it before you, tell them anyway.