That's why I carry a sharp folding knife on me at all times wherever (legally) possible. I have been involved in several rescue situations where I needed to cut webbing or ropes quickly. For many years now my primary EDC has been a Spyderco Endura with the Wave feature. I really like the Wave because it lets me deploy the knife pretty much instantly and doesn't require any fine motor skills. Of course, keeping the blade hair-popping sharp helps, too. It cuts webbing like a demon. A serrated blade might be even better, but less versatile for other purposes.

I have several other seatbelt cutters and rescue tools but for some reason I find them less practical and less efficient in terms of sheer cutting performance.

Now I'm thinking EMT shears might be a really good idea in places where carrying a knife is prohibited. I don't really have a whole lot of good hands-on experience with EMT shears, though. The ones I've handled were mostly low quality, cheap imports, more or less disposable stuff that wouldn't handle tougher jobs very well. Does anyone have any good recommendations? I noticed Leatherman has come up with new EMT shears, too. A bit pricy IIRC, but seemed pretty sturdy and well thought-out.