Which of the following increases the chances of a vehicle hydroplaning?

Worn tires significantly increase the chances of a vehicle hydroplaning because their tread depth is insufficient to effectively channel water away from the tire's contact patch with the road surface. Tread grooves are designed to disperse water, allowing the tires to maintain grip on the road. When tires are worn down, they lose their ability to perform this function, and even a small amount of water on the road can create a situation where the tires lose contact with the surface, leading to hydroplaning.

In contrast, new tires typically have deeper treads, which enhance their water displacement capability, reducing the likelihood of hydroplaning. Maintaining proper tire pressure is also crucial; overly high or low pressure can affect tire contact with the road, but worn tires pose a more direct risk in wet conditions. Weather conditions such as cold might influence the overall road conditions, but they do not directly cause tire degradation like worn tires do.