The cause of brake pads cracking is usually because the brake pad is not releasing from the brake rotors far enough when you remove your foot from the brake.
When the brake pads are not moving away from the brake rotor then the brake rotor continues to rub against the brake pad which heats the brake pad up and causes it to crack.
Overuse of the brakes or riding the brakes can also cause the brake pads to crack and when you have brake pads that are cracked you may need to replace the brake calipers as well if they are stuck.
If the brake pad is just broken meaning the friction material is broken but still attached to the backing plate of the brake pad then it's safe to drive for a little bit until you can get the broken brake pads replaced.
However it's best to replace the broken brake pads with new ones before it comes apart completely and prevents you from stopping.
Although your back brakes and your other brakes in the front will help stop you.
But it's best to be safe and get your brake pads replaced before they break even further and come apart or wear down too much.
You need your brakes to stop that vehicle or you could get into a serious auto wreck.
Replacing brake pads yourself is cheaper than having a shop replace the brake pads.
When you replace the brake pads yourself you only spend your time and the cost of the brake pads.
You do need some tools such as sockets, ratchets and a caliper compressing tool to compress the caliper piston back in to allow the brake caliper to fit with the new brake pads.
You can buy those tools pretty cheap and if you have a jack, jack stands, and are not afraid to get dirty then replacing the brake pads yourself can save you some money.
There's lots of good videos on YouTube showing how to replace the brake pads yourself and it can be down within an hour or less.
Brake pads cost between $15.00 to $50.00 per set depending on the make and model of vehicle.
If your brake rotors are bad then you also need to replace the brake rotors especially if they are really rusty, thin, glazed, cracked etc.
I replace my brake rotors along with my brake pads every 2nd set of brake pads as it's just as easy to replace the brake rotors then as well.
I buy my brake pads and brake rotors online through Ebay which saves me money.