3. In this Schedule—
“on-slip road” means a slip road intended for use of traffic entering the M25;
“off-slip road” means a slip road intended for use of traffic exiting the M25;
“spur road” is a reference to lengths of carriageway forming a spur of the M25; and
“linking carriageway” is a reference to a carriageway (or specified length of the carriageway) linking a part of the M25 to another part of that motorway or to another motorway.