The groove where the wear indicator is located is 1/16 inch (1.6 mm) shallower than elsewhere on the tire. If the tread has worn so that the indicator is exposed, replace the tire.
Worn out tires have poor traction on wet roads.
Honda Civic Service Manual. Steering Tie-Rod End Ball Joint Boot Replacement
5111A8 LEFT
5111A9 RIGHT
5111B0 BOTH
1.
Vehicle Lift
1.
Raise the vehicle on a lift, and make sure it is securely supported.
2.
Front Wheel
...