A MERCHANT, who shouted abuse at a police superintendent over a traffic incident in the presence of the officer's actress wife, yesterday agreed to be bound over to keep the peace. Lam Chun-wai, through the prosecution, also apologised to Chief Superintendent Chau Foo-cheong and his wife, Katherina Wu Kau-lam, also known by her stage name, Liu Ying-hung. Binding Lam over in the sum of $2,000 in his own recognisance for six months or four weeks' jail in default, magistrate Alan Wright at Eastern Court described the case as a ''silly'' incident. Lam, 44, represented by Cheng Huan QC, leading Bernard Chung, had pleaded not guilty to disorderly conduct in a public place and common assault. Crown Counsel Philip Ross said Mr Chau and his wife were travelling in their car along the eastbound carriageway of Tin Hau Temple Road on February 21. As they reached the junction of Dragon Road, they avoided a collision with a vehicle driven by Lam. Lam got out from his vehicle and shouted at Mr Chau, using abusive language, and twice tried to grab the officer. Although he revealed his identity, Lam also slapped the back of the policeman's hand.