Knokke-Heist is easily accessible by car via the major traffic axes E34, E40 and A11:
From Amsterdam, Düsseldorf, Antwerp, among others: E34 direction Knokke-Heist
From Cologne, Luxembourg, Brussels: E40 direction Bruges, then N31/A11
From e.g. London, Calais: E40 direction Bruges, then N31/A11
From e.g. Geneva, Paris: E403 direction Bruges, then N31/A11