How can I tell if my car tyres are worn?

Is there an easy way to know if the tread on my car tyre is worn? I know that worn tyres will fail my car's MOT. How do I check?
Amanda, September 2003


done
hiya on all new tyres now there is a yellow tag which becomes prominent when the tyre gets to the minimum tread, hope this helps....

m.staniforth, October 2007
I'm not a car driver but can't you tell just by looking? Bald patches etc? Sorry if that appears obvious. Michelin recommend this though:

Whether you have front or rear wheel drive, we recommend that you use newer tyres for the rear set, for extra safety in unforeseen or difficult situations (emergency braking, tight bends etc) particularly on wet surfaces.

Apparently front wheels are easier to control.

Mickey @ www.thedailypunt.com, December 2005
take a penny and hold it so Lincoln's head is pointed toward the center of the tire at the top of the tire. Place the penny inbetween the tread and if the tread comes above his head, you have some tread left. If it comes to the top of his head or less, replace the tires immediately

mcneel, October 2005
Amanda,

As you are aware

MOTOR VEHICLES
Chapter 90: Section 7Q Tire tread depth regulations; compliance; operation of vehicle prohibited

Section 7Q. No person, knowing that any tire of a motor vehicle fails to comply with regulations promulgated by the registrar relative to the minimum standards for visual and tread depth, shall operate such vehicle upon any way; and no owner of a motor vehicle, knowing that any tire of such vehicle fails to comply with such regulations, shall permit such vehicle to be so operated

Try and use some common sense there love eh?

kompressaur @ www.punterslounge.com, April 2004
Amanda, your tyres probably have Tread Wear Indicators. Look in the groves of your tyres. Some of them will have extra little lumps/moulded bits of plastic. These are the Tread Wear Indicators. These should be deep in the grove. If your tyres have worn down to the point where the Tread Wear Indicator is level with the tyre's rubber (not deep in the grove) then it is time to change your tyres.

Steve Kitchen, September 2003