Defendant was charged with aggravated DUI and aggravated driving while license revoked (DWLR). Officer's observations justified investigatory traffic stop, when he twice saw Defendant deviate from his own lane into another lane for no obvious reason. Motor Vehicle Code provision for improper lane usage contains no distance requirement; thus, it is irrelevant to officer's justification for investigatory stop whether motorist has driven for any appreciable distance in more than one lane. (KILBRIDE, FREEMAN, THOMAS, GARMAN, BURKE, and THEIS, concurring.)