Guide rail/In-car equipment

The guide rail is what allows for the safe and precise movement of the car and counterweight.
This rail offers a path for the elevator to ascend and descend. The component which comes into contact with the guide rail and the car is called the guide shoe. The guide shoe reduces friction through the application of lubricant. Roller guides, which have more friction-reducing functionality, are used for high-speed elevators.

Guide Rail is a term that was created because of the accident lawyers suing the state, claiming that "Guard Rails" didn't guard vehicles from crashing through them.  This claim was made again a few years ago by a lawyer working for the father of a kid who got tanked well over the limit, then crashed through numerous signs and rails and drowned in the Union Canal.

The rails were never designed to prevent all vehicles from crashing through them, but rather to re-direct errant vehicles back on to the travelled way.  Despite the sad feelings of a family losing a loved one, they were never intended to guard drunk drivers from meeting tragic ends to their lives. 

Yet lawyers still try to make that claimt, so the word "Guard" was replaced with "Guide" in all of the legal documents.  A few of the design geek-types that Val referred to will always use that term to sound official, but everyone else uses the word guard in ordinary speech.